viscoelastic, spectroscopic, and microscopic characterization of novel bio-based plasticized...

Research ArticleViscoelastic Spectroscopic and Microscopic Characterization ofNovel Bio-Based Plasticized Poly(vinyl chloride) Compound

Mei Chan Sin1 Irene Kit Ping Tan12 Mohd Suffian Mohd Annuar1 and Seng Neon Gan3

1 Institute of Biological Sciences Faculty of Science University of Malaya 50603 Kuala Lumpur Malaysia2 Centre for Research in Biotechnology for Agriculture (CEBAR) University of Malaya 50603 Kuala Lumpur Malaysia3 Department of Chemistry Faculty of Science University of Malaya 50603 Kuala Lumpur Malaysia

Correspondence should be addressed to Mei Chan Sin meichansin112gmailcom

Received 17 February 2014 Accepted 5 April 2014 Published 5 May 2014

Academic Editor Jan-Chan Huang

Copyright copy 2014 Mei Chan Sin et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Plasticized poly(vinyl chloride) (PVC) is one of the most widely consumed commodity plastics Nevertheless the commonlyused plasticizers particularly phthalates are found to be detrimental to the environment and human health This study aimedto investigate the ability of an alternative greener material medium-chain-length polyhydroxyalkanoates (mcl-PHA) a kind ofbiopolyester and its thermally degraded oligoesters to act as a compatible bioplasticizer for PVC In this study mcl-PHA weresynthesized by Pseudomonas putida PGA1 in shake flask fermentation using saponified palm kernel oil (SPKO) and subsequentlymoderately thermodegraded to lowmolecular weight oligoesters (degPHA) SEMATR-FTIR 1H-NMR andDMAwere conductedto study the film morphology microstructure miscibility and viscoelastic properties of the PVC-PHA and PVCdegPHA binaryblends Increased height and sharpness of tan 120575max peak for all binary blends reveal an increase in chain mobility in the PVCmatrixand high miscibility within the system The PVC-PHA miscibility is possibly due to the presence of specific interactions betweenchlorines of PVC with the C=O group of PHA as evidenced by spectroscopic analyses Dynamic viscoelastic measurements alsoshowed that mcl-PHA and their oligoesters could reduce the119879

119892of PVC imparting elasticity to the PVC compounds and decreasing

the stiffness of PVC

1 Introduction

Poly(vinyl chloride) (PVC) constitutes one of the largestglobally consumed commodity plastics approximately 16million tonnes per annum [1] PVC compounds in theplasticized form are widely used in the industry for variousflexible applications such as packaging toys and medicaland household products Conventional petrochemical-basedplasticizers for PVC particularly phthalates for examplediethylhexyl phthalates (DEHP) and diisononyl phthalates(DINP) are the predominant type of PVC plasticizer andaccounted for almost 86 of the world consumption ofplasticizers in 2008 [2 3]

Nevertheless several issues regarding the use of phthalateswere raised recently concerning the effects of phthalateson the environment human hormones and reproductivesystem as well as their exposures to children via breast milktoys and baby care products Based on a study in Norway

the bronchial obstruction in children was directly related tothe amount of plasticizer-releasing materials present in theindoor environment [4] According to Bornehag et al (2005)plasticizers that are present in the dust are the main elementscausing allergy asthma and inducing puberty among thechildren since they spent most of the time indoors [5]Another study showed that the phthalates actually mimickedfemale hormones and could serve as the endocrine disruptorsin humanbody resulting in feminization of boys [6] Recentlyin the 2011 Taiwan Food Scandal DEHP and DINP werereported as the carcinogenic plasticizer agents implicatedin human infertility problem and developmental problemsin children Research also showed that phthalates wereresponsible for cancer proliferation in mice and rats [7]These phthalate-based plasticizers are found to be harmful tohuman beings through direct contact with skin and tissuesThe risk of them leaching out from PVC compounds duringend-used applications to the environment or human body

Hindawi Publishing CorporationInternational Journal of Polymer ScienceVolume 2014 Article ID 846189 10 pageshttpdxdoiorg1011552014846189

2 International Journal of Polymer Science

is significant Therefore intense researches have been carriedout to seek alternative green plasticizer materials whichimpart low toxicity total or partial biodegradability andare economically and technically viable to substitute theconventional petrochemical-based plasticizers

Medium-chain-length polyhydroxyalkanoates (mcl-PHA) are bacterial polyesters comprised of six to fourteencarbon-chain-length monomers [8ndash10] which have biodegr-adable [11] biocompatible [12] and nontoxic [13] propertiesIn addition mcl-PHA can be synthesized from naturalrenewable resources such as plant oil [14] fatty acids [15] andagricultural wastes [16] Thus mcl-PHA fulfill all the desir-able traits of an alternative eco-friendly plasticizer materialThese bacterially produced polymers have sufficiently highmolecular weight in the range of 50000 to 300000 Dalton[17] As mcl-PHA also exhibit polar properties they havegreat potential to act as compatible plasticizer for PVC Inaddition possible entanglement between the PHA with PVCmay not allow for easy migration of the plasticizers out of theblended compounds Low molecular weight oligoesters canbe produced frommcl-PHA by thermal degradation processThese oligomeric hydroxyalkanoic acids possess favorableend groups and such fragments could be used as PVCplasticizers as well This is different from the conventionalpetrochemical-based plasticizers which are small moleculesthat intercalate into PVC and thusmay have limited residencetime in the PVC compound In the event of accidental ornatural migration from the blended compounds the PHAplasticizers would not be hazardous to human health andthe environment due to their nontoxic biodegradable andbiocompatible properties

In this work saponified palm kernel oil (SPKO)-derivedmcl-PHA and their low molecular weight oligoesters weremixed with PVC at the compositions of 25 and 5 parts perhundred parts (phr) of PVC through solution blending ThePVCPHA binary blends were solvent-casted and character-ized to study the polymer film morphology microstructurePVC-PHA interactions miscibility between the two poly-mers and viscoelastic properties of the PVCPHA polymerblends

2 Experimental Sections

21 Materials Poly(vinyl chloride) (PVC) with molecu-lar weight approximately 100000 gmolminus1 (BDH laboratoryreagent) was used throughout the experiments Mcl-PHAwere produced in a two-stage culture system which consistedof cell-growth phase and PHA-accumulation phase In thefirst phase the Pseudomonas putida PGA1 were grown innutrient broth (80 g Lminus1) a nutritionally rich medium toproduce high concentration of cells After 20 hours ofincubation the cells were harvested by centrifugation at8000 rpm for 30 minutes at 4∘C then washed with 085saline and transferred to the modified nitrogen-limiting M9medium [18] containing 05 (wv) saponified palm kerneloil (SPKO) [19] as the sole carbon source to induce PHAbiosynthesis by the cells The bacteria were further cultivatedin PHA production medium for 72 hours at 200 rpm and

30∘C The bacterial cells were then aseptically harvested bycentrifugationThe cells were washed twice with sterile 085saline and dried at 70∘C in a hot air oven to constant weightThe dried cells were washed with polar solvent to removeresidual carbon substrates and metabolic wastes from thebiomass by suspending them in 95 analytical grade ethanoland shaking for 30 minutes at 22 plusmn 1∘C and 160 rpm inthe orbital shaker incubator Oily residues and other polarlipids attached to the cells would dissolve in the alcoholwhich was decanted off The cells were then dried in ovenat 70∘C to constant weight Intracellular mcl-PHA wereextracted by suspending the dried cells in analytical gradechloroform and refluxed for 6 hours at 70∘C The PHA-chloroform solution was filtered through Whatman number1 filter paper to remove the cellular debris and the filtrate wasconcentrated by rotary evaporation The biopolymers werepurified by drop-wise addition of the extract into rapidlystirred methanol chilled with ice bath Further purificationwas carried out by redissolving the PHA in a small amountof chloroform and reprecipitating it in excess methanol Itwas then dried in a vacuum oven at 37∘C 06 atm for 48hours Lowmolecular weight PHA oligoesters were producedthrough mild thermal degradation of the polymer The mcl-PHA samples were thermally degraded at temperatures of170∘C At such temperature the heat-treated PHA (degPHA)is mainly composed of a mixture of oligomeric hydroxyacid fragments without terminal unsaturated fragments Thethermal degradation process was performed using similarprocedure as described earlier [15 18 20]

22 Gel Permeation Chromatography (GPC) Analysis of PHAand degPHA The number average molecular weight (119872

119899)

weight average molecular weight (119872119908) and polydispersity

index (PDI) of PHA and degPHA used in the blendingwere determined by gel permeation chromatography (GPC)analysis GPCwas performed using aWaters 600-GPC (USA)instrument equipped with Waters Styragel HR columns(78mm internal diameter times 300mm) connected in series(HR1 HR2 HR5E and HR5E) and a Waters 2414 refractiveindex detector Approximately 1000 120583L of 20mgmLminus1 poly-mer sample was eluted by THF at a flow rate of 1mLminminus1at 40∘C The instrument was calibrated using monodispersepolystyrene standards

23 Gas Chromatography (GC) Analysis of PHA and degPHAAnalysis of PHA and degPHAmonomeric compositions wasperformed using a GC 2014 Shimadzu (Japan) equippedwith a SGE forte GC capillary column BP20 (30m times025mm internal diameter times 025 120583m) (Australia) and aflame ionization detector (FID) In the GC analysis 10 120583Lof sample was injected by split injection with a split ratioof 10 1 using a SGE 100 120583L syringe Nitrogen was used asthe carrier gas at a flow rate of 3mLminminus1 The columnoven temperature was programmed from 120∘C for 2minat the start ramped up at a rate of 20∘Cminminus1 to 230∘Cand held at this temperature for 10min The temperaturesof injector and detector were set at 225∘C and 230∘C

International Journal of Polymer Science 3

respectively 3-Hydroxyalkanoic acid methyl ester stan-dards 3-hydroxybutyric acid (3HB C

4) 3-hydroxyhexanoic

acid (3HH119909 C6) 3-hydroxyoctanoic acid (3HO C

8) 3-

hydroxydecanoic acid (3HDC10) 3-hydroxydodecanoic acid

(3HDD C12) 3-hydroxytetradecanoic acid (3HTD C

14) and

3-hydroxyhexadecanoic acid (3HH119909D C16) methyl esters

(Larodan) were used to determine the respective retentiontimes for monomer identification

24 Blending of PHA and degPHA with PVC A 0625wv of PHA solution (200mL chloroform containing 0125 gPHA) and 125 wv of PHA solution (200mL chloroformcontaining 025 g mcl-PHA) were prepared These solutionswere then added to the 5 wv PVC solution (1000mLchloroform containing 50 g of PVC) at two ratios yielding25 phr (parts per hundred PVC resin) and 5 phr (parts perhundred PVC resin) of PVCPHAbinary blends respectivelyThe binary blends were designated as for example PSP

25

and PdeSP25

representing blends of 25-part polymeric PHAand oligomeric degPHAwith 975-part PVC respectively andPSP5and PdeSP

5representing blends of 5-part polymeric

PHA and oligomeric degPHAwith 95-part PVC respectivelyThe lightly plasticized PVC films were prepared by

mixing mcl-PHA at compositions of 25 and 5 parts perhundred (phr) parts of PVC resin by solution blendingusing chloroform (analytical grade Merck) as the commonsolvent The solution blends were poured into glass Petridishes and dried in vacuum oven at 70∘C for one week toremove residual solvent The PVCchloroform solution wasfirst mixed at 500 rpm and refluxed at 55∘C in a flat roundbottom flask connected to Liebig condenser with a reductionadaptor for 30 minutes After the specified reaction time thePHAchloroform solutionwas added to the PVC solution andthe mixture was allowed to mix thoroughly at 500 rpm and55∘C for one hour The reactor was placed in a thermostatedwater bath and the level of the water was kept at least 2 cmabove the level of the solution in the reaction flask forhomogeneous temperature equilibrium Upon completion ofblending the PVCPHA was solvent-casted in a glass Petridish and was stirred to slowly evaporate off the solvent inthe fume hood at room temperature The casted films werefurther dried under vacuum at 60 to 70∘C for two daysfollowed by drying in hot air oven at 70 to 72∘C for one weekto allow for complete removal of the traces of residual solvent

25 Characterizations of PVC-PHABinary Blends ThecastedPVCPHAfilmswere studied by various analytical techniquessuch as scanning electronmicroscopy (SEM) attenuated totalreflectance-Fourier transform infrared spectroscopy (ATR-FTIR) proton nuclearmagnetic resonance spectroscopy (1H-NMR) and dynamic mechanical analysis (DMA) for thepolymer film morphology PVC-PHA interactions miscibil-ity between the two polymers and viscoelastic properties

251 Scanning Electron Microscopy (SEM) The PVCPHAsample filmswere examined by scanning electronmicroscopy(SEM) to study the microstructure and surface morphologyof the thin films SEM microscopy was performed using

a SEM Zeiss Auriga (Germany) under magnifications of500x Uncoated samples were used in this SEM studyusing low operating voltage around 1 kV and LaB

6 Field

Emission as electron source Samples were mounted ontothe specimen holder using conducting carbon-impregnatedtape At normal operating voltages (10 to 30 kV) the contrastdifferences between phases with different compositions areinherently lower in resolution in the backscattered (BS) imagethan the secondary image [21] By working at low operatingvoltages subtle variations in the chemical compositions ofblend components are sufficient to produce contrast in thesecondary images and therefore high-quality images arepossible to be obtained

252 Attenuated Total Reflectance-Fourier Transform InfraredSpectroscopy (ATR-FTIR) The structural and functionalgroups present in the PVC PHA and PVCPHA sampleswere analyzed by Perkin-Elmer FTIR-ATR spectrometer(USA)The IR spectra of the thin films preparedwere scannedat a wavelength of 4000 to 450 cmminus1 with a resolution of4 cmminus1 and recorded after 4 scans

253 Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR) 1H-NMR analysis of PVC PHA and PVCPHAsamples was carried out on a JEOL JNM-LA 400 FT-NMRspectrometer (Japan) operating at 400MHz About 200mgof the sample was dissolved in 1mL of deuterated chloroformThe integration value of 120572-methine proton (ndashCHClndash) of PVCwas chosen as the reference andwas assigned the value of 100

254 Dynamic Mechanical Analysis (DMA) Miscibilitybetween two polymers is usually characterized by usingdynamic mechanical analysis (DMA) DMA is also analternative method to study the viscoelastic properties ofa polymer blend for example storage modulus (1198641015840) lossmodulus (11986410158401015840) and loss angle tangent (tan 120575) [22] Generallyfor an immiscible blend the loss modulus curves show thepresence of two damping peaks corresponding to the 119879

119892s of

individual components [23] For a highly miscible blend thecurve shows only a single peak whereas broadening of thetransition occurs in the case of partiallymiscible systems [24]

In this study viscoelastic properties of PVCPHA poly-mer blends were characterized by TA DMA Q800 dynamicmechanical analyzer using a tension film clamp Beforebeing subjected to the mechanical testing sample films wereprepared using a hot press (Carver Instrument Model CSN 40000-715) Specimens were heated pressed to a specifictemperature at 45 psi applied load and held for 2minfollowed by cooling to ambient temperature Strips of thinfilmswith 300mmfixed length were thenmounted to the TADMA Instrument and the measurements were made underthe temperature scanmode ranging fromminus40 to 120∘C undera heating rate of 5∘Cminminus1 and at a frequency of 1Hz Liquidnitrogen was used in the Cryospeed the cooling accessory toachieve subambient temperature in this testing

Mechanical properties of polymer show profoundchanges in the region of the glass transitions For examplethe elastic modulus may decrease by a factor of over


1000 times as the temperature is raised through the glasstransition region For this reason 119879

119892can be considered the

most important material characteristic of a polymer as faras mechanical properties are concerned Besides that 119879

119892has

important theoretical implications for the understandingof the macromolecular mobility in the polymer 119879

119892can be

determined from the onset of the storage modulus (1198641015840) dropthe onset or peak of loss modulus (11986410158401015840) and the onset orpeak of the tan 120575 curve [25] In our analysis the 119879

119892values

were determined from the maximum peak of loss moduluscurves All temperatures were recorded in degrees Celsius

26 Study of Elastic Modulus of PVCPHA Blends Elasticmodulus is the mathematical description of a polymerrsquostendency to be deformed elastically when a force is appliedto it It is a measure of the stiffness of a component Astiff component with a high elastic modulus will showmuch smaller changes in dimensions In general engineeringapplications view stiffness as a function of both the elasticmodulus and the geometry of a component Elastic modulus(119864) of PVCPHA and PHVdegPHA samples was determinedby adapting the elastic modulus equation from the modelequation in the TA DMA Q800 Equation Guideline withthe relationship of the stiffness elastic modulus and samplersquosgeometry for the sample analyzed on a film tension clamp asshown below

119870 =(119860 times 119864)

119871 (1)

where119870 is stiffness (Nmminus1) 119864 is elastic modulus (GNmminus2)A is sample cross-sectional area (cm2) and 119871 is sample length(cm) As the sample has a very small area as compared toits length no end effects correction is needed therefore themodulus equation is derived as follows

119864 = 119870119904times119871

119860 (2)

where 119864 is elastic modulus (GNmminus2) A is sample cross-sectional area (cm2) 119871 is sample length (cm) and 119870

119904is

measured stiffness (Nmminus1)

3 Results and Discussion

31 MolecularWeight andMonomer Composition of PHA119878119875119870119874

and degPHA119878119875119870119874

The average molecular weight and molec-ular weight distribution of both PHASPKO and degPHASPKOwere determined by GPC analysis and the results weresummarized in Table 1 As shown in the table the numberaveragemolecular weight (119872

119899) andweight averagemolecular

weight (119872119908) of PHASPKO decreased when the polymers were

heat-treated at 170∘C Heating PHASPKO at 170∘C resulted inthe reduction of molecular weight producing a mixture oflow molecular weight hydroxyl alkanoic acids Besides thatan increase in polydispersity index (PDI) in degPHA wasobserved and this indicated that these polymers had broadermolecular weight distribution as various lower-molecular-weight species were generated at high temperature of partialthermal degradation

Table 1 also shows the relative monomer compositionsof PHASPKO and degPHASPKO which were used in the PVCblending The oligomeric PHA contained higher amount ofshorter side chain monomers (C

6and C

8) compared to the

polymeric PHA For example the amount of shorter sidechain monomers for degPHASPKO was 521 wt which washigher than those shorter side chain monomers present inPHASPKO (508 wt)

32 SEM of PVC PHA PVCPHA and PVCdegPHA FilmsSEM is used to examine the surface variations of poly-mer blends and provide qualitative comparisons for blendsmorphology [21] In order to understand how the surfacemorphology of the PVC film changes with the introductionof plasticizers the SEM micrographs of the pure PVC PHAPHAPVC and PHAdegPVC films were taken

As shown in Figure 1(a) cavities were present in theindividual PVC film The pores were distributed throughoutthe surface with the pore size in the range of 1 to 20120583mThese observations were similar to the findings reportedby Stephan et al (2000) [26] Figure 1(b) showed the sur-face morphology of SPKO-derived PHA (PHASPKO) filmPHASPKO physically and morphologically existed as softerand amorphous material and thus appeared as a smooth filmwithout any cavity After mixing the PVC with both PHAand degPHA the cavities were not as clearly observed as inpure PVC film but the PHA and PVC resin molecules wereobserved to be engaged in a continuous solvation-desolvationphase while the PVC resin macromolecules were joining in acontinuous aggregation-disaggregation phase (Figures 1(c)ndash1(f)) As could be seen in the figures the PHA could bepenetrated to some of the porous structures of PVC andinterfused with the PVC polymer segments

33 ATR-FTIR Analysis of PVCPHA System ATR-FTIRspectroscopy is often used in the analysis of polymer blendIn this study ATR-FTIR spectroscopy was used to investigatewhether specific interaction between the PHA and PVC hadtaken place which could be observed from the shift of certainpeaks in the spectrum The characteristic bands of PVC canbe classified into three regions (i) the CndashCl stretching regionin the range from 600 to 700 cmminus1 (ii) the CndashC stretchingin the range from 900 to 1200 cmminus1 and (iii) from 1250 to2970 cmminus1 attributed to numerous CndashH modes in PVC [27]On the other hand themcl-PHApolyesters had characteristicstrong absorbance bands at around 1726 cmminus1 which wereattributed to the C=O stretching Therefore it is convenientto differentiate the PHA from PVC by the carbonyl band

Figure 2 shows the ATR-FTIR absorption spectra ofPVC PHA PVCPHA and PVCdegPHA blends All theblends showed the characteristic peaks of both PHA and PVCcomponents that is the C=O stretching band at around 1737to 1740 cmminus1 and CndashCl stretching around 607 to 610 cmminus1indicating that both polar functional groups of mcl-PHAand PVC were present in the polymer blends As shownin Figure 2(a) the C=O stretching frequency for PHASPKOwas observed at 1726 cmminus1 After mixing the PVC with 25and 5 phr of PHASPKO the peak maximum position was


Table 1 Molecular weight distribution and monomer compositionsof PHASPKO and degPHASPKO determined by GPC and GC analysesrespectively

Sample Molecular weight distribution Monomer composition (wt)1119872119899

2119872119908

3PDI C6 C8 C10 C12 C14 C141

PHASPKO 32700 60000 18 45 463 326 134 16 16degPHASPKO 18200 42000 23 49 472 324 126 17 121119872119899 number average molecular weight 2

119872119908 weight average molecular weight 3PDI polydispersity index C6 3-hydroxyhexanoic acid C8 3-hydroxyoctanoic acid C10 3-hydroxydecanoic acid C12 3-hydroxydodecanoic acid C14 3-hydroxytetradecanoic acid C141 3-hydroxytetradecenoic acid

Cavities

10120583m

(a)

10120583m

(b)

10120583m

(c)

10120583m

(d)

10120583m

(e)

10120583m

(f)

Figure 1 SEM micrograph showing surface morphology of (a) PVC (b) PHASPKO (c) PSP25 (d) PSP5 (e) PdegSP25 and (f) PdeSP5films

(500x magnification)

shifted to higher frequency that is 1737 cmminus1 for PSP5and

1740 cmminus1 for PSP25 Similarly the ester carbonyl stretching

frequency for degPHASPKO was observed at 1727 cmminus1 Aftermixing the PVC with 25 and 5 phr of degPHASPKO the peakmaximum position was shifted to 1738 cmminus1 for PdeSP

5and

1739 cmminus1 for PdeSP25 On the other hand the shift of the

CndashCl stretching frequency from 616 cmminus1 (PVC) to lowerfrequencies was also observed in the blends with PSP at607 to 608 cmminus1 and PdeSP at 609 to 610 cmminus1 From theobservations for the shift of both ester carbonyl and CndashClstretching in all polymer blends it is believed that the C=Ogroup in PHA could be responsible for the miscibility with


1726PHASPKO

PSP5

PSP5

PSP25

PSP25

1737

1741

PVC

PVC616

607

608

3000 2000 1500 1000 4500

0360

034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

A

(cmminus1)

(a)

0350034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

40000 3000 2000 1500 1000 4500

1727degPHASPKO

PdeSP5

PdeSP5

1738

PdeSP25

PdeSP25

1739

PVC

PVC616

610

609

A

(cmminus1)

(b)

Figure 2 ATR-FTIR absorption spectra of (a) PVC PHASPKO and PSP and (b) PVC degPHASPKO and PdeSP

the PVC Therefore it is hypothesized that specific polarinteractions between the PHA and PVC had taken place

The relative intensity ratio between absorbance value forC=O stretching in PHA and nonreactive CH bending inPVC (119860

17391198601426

) for PSP25 PdeSP

25 PSP5 and PdeSP

5

was 047 039 076 and 063 respectively PVC blendedwith PHASPKO (119872

11990860000 gmol) had higher relative ratio of

11986017391198601426

than with those blended with degPHASPKO (119872119908

42000 gmol) since PHASPKO has higher molecular weightand longer polyester chainwhich subsequently hasmore esterC=O carbonyl group Thus the polymeric PHA may haveincreased level of interaction with the PVC On the otherhand PVC blended with 5 phr PHA had higher relative ratioof 11986017391198601426

than with 25 phr PHA As higher amountof PHA is present in the polymer mixture higher amountof polar groups in the polymer is available for possibleinteraction with PVC It should be noted that polar groupsin a plasticizer are essential for good compatibility as it isthe case of like dissolving like When plasticizer moleculesare introduced into the polymer mass polymer chains areseparated by the plasticizer molecules which are able to lineup their dipoles with the polymer dipoles Polymer chainsseparated in this way are more easily moved relative to theones that are bonded very closely In addition highmolecularweight of a plasticizer reduces its ability to shield polymerdipoles with this subsequently reducing the mobility amongthe polymer chain [28]

34 1H-NMR Analysis of PVCPHA System Nuclear mag-netic resonance (NMR) spectroscopy is one of the techniqueswhich could provide information on a molecular dimensionscale for the polymer-polymer interaction Figure 3 showed

the proton NMR spectra for PVC PHA PVCPHA andPVCdegPHA blend respectively

In Figure 3(a) the peaks around 43 to 46 ppm wereassigned to the 120572-methine proton (ndashCHClndash) which attachedto the electropositive carbon atom and peaks around 19 to23 ppm were assigned to the 120573-methylene proton (ndashCH

2ndash)

in PVCThe relative intensity ratio of 120572H (120572-methine proton)to 120573H (120573-methylene proton) was 1 2 in agreement with thestructure of the repeating unit The peak at 15 ppm was dueto the moisture in the D-chloroform This could be due tothe relatively low solubility of PVC in the chloroform andtherefore small amount of water in the solvent could bedetected in the spectrum Figure 3(b) showed the 1H-NMRspectrum of PHA The peak a at 08 ppm and peak b at12 ppm were assigned to the methyl (ndashCH

3) and methylene

(ndash(CH2)119899ndash) group in the PHA side chain respectively Peak

c at around 15 ppm was assigned to the methylene (ndashCH2ndash)

group attached to the carbon adjacent to the oxygen atomThese three peaks a b and c are the characteristic peaksof PHA which could be used to validate the presence ofpolyester in the polymer blendsThepeak d at around 25 ppmrepresented the methylene group at the 120572-position of theester

As could be seen from Figures 3(c)ndash3(f) the spectra ofPVCPHA and PVCdegPHAblends showed almost identicalpeaks as PVC with three additional peaks being detected08 ppm 12 ppm and 15 ppm which are assignable to ndashCH3 ndash(CH

2)119899ndash and ndashCH

2ndash groups in PHA respectively

The integration of these peaks appeared to be much smallerin the PVCPHA blends revealing that only small amountof PHA was present in the blends A new small peak ataround 25 ppm as indicated by the arrows appeared in the


120573-Methylene proton120572-Methine proton

(ppm)4 3 2

100

201

011

Polymer Polymer

H H

H Cl

C C120572120573

1

1

112

22

(a) PVC

CH3

CH2

O CH CH2 C

O

O CH CH2 C

O

O

CH3

CH2

CH

CH

CH2

100 216

218

890

342

(ppm)6 4 2

]n[

a

bc

d e

e d

c

b

a

(CH2)x

(CH2)6

(b) PHASPKO

100

133

067

019

6 4 2

(ppm)

(c) PSP25

6 4 2100

177

069

033

011

(ppm)

(d) PSP5

100

158

042

026

6 4 2

(ppm)

(e) PdegSP25

100

166

066

036

013

6 4 2(ppm)

(f) PdeSP5

Figure 3 1H-NMR spectra of (a) PVC (b) PHASPKO (c) PSP25 (d) PSP5 (e) PdegSP25 and (f) PdeSP5binary blends

PVCPHA and PVCdegPHA blend This peak was ascribedto the 120572-hydrogen adjacent to the ester group in PHA whichwas partially overlapped with the peak broadening of beta-H in PVC From these observations it was proposed thatspecific intermolecular interactions could be present withinthe polymer mixtures and the two polymers may interminglewith each other on a molecular level

35 Dynamic Mechanical Analysis of PVCPHA SystemMechanical compatibility with property conciliation betweenthe components is assured for a miscible and compatible

polymer mixture Dynamic mechanical analysis (DMA) is amethod commonly employed to provide direct quantitativemeasurement of the modulus explicating phase transitionbehavior as a function of temperature [29 30]The differencebetween homogeneous and heterogeneous blends is easilydetected in the mechanical loss and modulus-temperaturedata A miscible polymer blend usually shows a single andunique transition in the modulus-temperature curve [31]

A miscible system is formed when there are specificpolymer-polymer interactions in a mixture of two polymersThese miscible blends are expected to show a single 119879

119892


200000

150000

100000

50000

040 60 80 100 120

Stiffness

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PSP25

PSP5

(a)

200000

150000

100000

50000

040 60 80 100 120

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PdeSP25

PdeSP5

(b)

Figure 4 Temperature variation of filmrsquos stiffness for (a) PVC PSP25 and PSP

5and (b) PVC PdeSP

25 and PdeSP

5

value and a single modulus transition zone which variesregularly with the blend composition [32] In this study 119879

119892

was determined from the maximum peak of loss modulus(11986410158401015840) curve Both PVC and PHASPKO have 119879

119892of 919∘C and

minus368∘C respectively On the other hand dynamic mechan-ical measurements showed a single 119879

119892for all PVCPHA (119879

119892

834∘C for PSP25

and 119879119892 827∘C for PSP

5) and PVCdegPHA

(119879119892 809∘C for PdeSP

25and 119879

119892 797∘C for PdeSP

5) binary

blends revealing that the PHA were highly miscible withPVC Overall the 119879

119892of all plasticized PVC were lower than

the PVC with 119879119892of PVCPHA

5lower than PVCPHA

25and

119879119892of PVCdegPHA lower than PVCPHA A higher content

of PHA in PVCPHA led to a lower 119879119892valueThis means that

the plasticization of PVCwas enhanced by higher amounts ofPHAThis could be due to more PHA embedding themselvesbetween the PVC chains thus spacing the latter furtherapart to increase the polymer chain mobility Polymer blendscomposed of PVC and the oligoesters as plasticizer showedlower 119879

119892than the blends composed of polymeric polyesters

As low molecular weight plasticizers possessed more endgroups this would accordingly increase the mobility amongthe PVC polymer chains thus softer plasticized films withbetter plasticizing effect would be formed

Apart from that a ratio of loss modulus (11986410158401015840) to storagemodulus (1198641015840) is known as the loss angle tangent (tan 120575)which represents the main relaxation associated with theglass-rubber transition It is the dissipation factor whichis defined as the loss modulus over the storage modulusThis value (dimensionless) can be attributed to the changefrom rigidity to flexibility [33] The tan delta peak maximum(tan 120575max) of PVC was about 074 All PVCPHA showedhigher and sharper tan 120575max peak compared to PVC (datanot shown) indicating the high miscibility of the system All

binary blends have higher values of tan 120575max than the PVCshowing some level of dynamic homogeneity in the blendIn other words the blends appear to be miscible and have anarrow range of relaxation timesThismay be due to the closemolecular proximity of the like chains Overall the values oftan 120575max for PVCPHA

5are higher than PVCPHA

25and

PVCdegPHA higher than PVCPHAThe increase in the tan 120575max in PVCPHA was possibly

due to the reduction in the crystalline volume of the PVCsystem in the presence of PHA plasticizer According toMadera-Santana et al (2009) a reduction of sharpness andheight of the tan 120575max peak is due to the restriction of thechain mobility in the polymer [34] Therefore increasing thePHA content of the blend increases the chain mobility in thePVC matrix and led to a sharper and height increment oftan 120575max during dynamicmechanical deformationThe valuesof tan 120575max of all binary blends approach 100 indicatingthat backbone chains in the polymer blends exhibit gradualslippage and result in a springy and rubbery nature ofplasticized PVC compound

It is known that the extent of decrease in stiffness andchanges in the softness of the plasticized PVC depend onboth the level of plasticization and the nature of the plasticizer[35] As discussed earlier introduction of the plasticizer intothe polymer system greatly increased the mobility amongthe polymer chain and this subsequently augmented thesoftening of the polymer Figure 4 revealed the temperaturevariation of filmrsquos stiffness for all the plasticized PVC

As shown in Figure 4 the stiffness of PVCPHA wasdecreased when the proportion of PHA was increasedAccording to Wypych (2004) when larger quantities ofplasticizers were added into the PVC more amorphous areasof the PVC were swollen [36] This would lead to increasedease of movement of the macromolecules thus making the


plasticized PVC more flexible This could be seen from thedecreased stiffness of the binary blends when the amountof PHA was increased in the blend On the other handby comparing the filmrsquos stiffness of the PVCPHA withPVCdegPHAblends at 40∘C it could be seen that addition oflowmolecular weight PHA could provide greater flexibility tothe PVC compared to high molecular weight PHA by intro-ducing greater internal lubrication effectThe effectiveness inthe lubrication effect could be attributed to the widespreadspecific interactions between the shorter chain fragmentsof low molecular weight PHA with PVC promoted by theincreased hydroxyl and carboxyl end groups

36 Comparison of Elastic Modulus of PVC and PVCPHABinary Blends Elastic modulus (119864) is the mathematicaldescription of a polymerrsquos tendency to be deformed elasticallywhen a force is applied to it It is a measure of the stiffnessof a component A stiff component with a high elasticmodulus will show much smaller changes in dimensions Ingeneral engineering applications view stiffness as a functionof both the elasticmodulus and the geometry of a componentFor rigid PVC typical elastic modulus lies between 24and 41 GPa In this study the calculated elastic modulusfor the pure PVC was around 392GPa All PVCPHA andPVCdegPHA blends showed a considerable lower elasticmodulus than pure PVC Overall the effectiveness of reduc-ing the elastic modulus of the polymer was found to bebetter in PVCPHA

5(119864 172GPa for PSP

5and 119864 149GPa

for PdeSP25) as compared to PVCPHA

25(119864 326GPa for

PSP25

and 119864 194GPa for PdeSP25) better in PVCdegPHA

compared to PVCPHADecreased elastic modulus was observed in the polymer

blends with higher amounts of PHA and PHA in the formof oligoesters When higher amount of PHA was addedto the PVC more amorphous areas of the PVC particleswould be swollen and this would lead to increased ease ofmovement of the PVC macromolecules whereas oligomericPHA would augment the degree of chain movement andsegmental flexibility to the PVC chains in a greater extentand would therefore increase the softening properties of theblends

4 Conclusions

SEM micrographs of PVCPHA and PVCdegPHA filmsshowed that introduction of low amount of PHA in the binaryblends results in penetration of PHA polymers into some ofthe porous structures of PVC and subsequently interfusedwith PVC polymer segments Spectroscopic analyses con-firmed the presence of both polar functional groups of PHAand PVC in the binary blends It is postulated that the PVC-PHA miscibility was due to the specific interactions betweenthe polar ester groups of PHA with the CH-Cl group of PVCDMA measurements showed a single 119879

119892for all PVCPHA

and PVCdegPHA indicating that the PHA were misciblewith PVC Decreased 119879

119892 stiffness and elastic modulus were

observed in the polymer blends with higher amounts of PHAand PHA in the form of oligoesters When larger quantities

of PHA plasticizers were added to the PVC more amorphousareas of the PVC particles would be swollen and this wouldlead to increased ease of movement of the PVC macro-molecules On the other hand low molecular weight PHAwould increase the degree of chain movement and segmentalflexibility to the PVC chains to a greater extent and wouldtherefore impart plasticization effect to PVCmore effectivelycompared to high molecular weight PHA In summary mcl-PHA and the oligoesters were shown to be a compatibleplasticizer for PVC as they have reasonable apparent affinitytowards the PVC resin due to the presence of some levelsof intermolecular attraction between the polymers and theycould impart flexibility to the PVC compound

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgment

The authors wish to acknowledge the support of the Univer-sity of Malaya through research Grants 39-02-03-9057 PS1552009A and PS 2952010B

References

[1] PVC Information Council PVC Factsheet No 2 EuropeanCouncil of Vinyl Manufacturers 1995

[2] A Marcilla S Garcıa and J C Garcıa-Quesada ldquoStudy of themigration of PVCplasticizersrdquo Journal of Analytical andAppliedPyrolysis vol 71 no 2 pp 457ndash463 2004

[3] S Bizzari M Blagoev and A Kishi (SRI Consulting MenloPark Calif USA) 2009

[4] Plastermart ldquoAn overview of plasticizers and their effects onhuman health and environmentrdquo Technical articles and reportson plastic industry 2008

[5] C-G Bornehag B Lundgren C J Weschler T Sigsgaard LHagerhed-Engman and J Sundell ldquoPhthalates in indoor dustand their association with building characteristicsrdquo Environ-mental Health Perspectives vol 113 no 10 pp 1399ndash1404 2005

[6] Third national report on human exposure to environmentalchemicals Department of Health amp Human Services Atlanta(CDC U S) 2005

[7] National Toxicology Program No NTP Tech Rep Ser TR no217 1982

[8] A Timm and A Steinbuchel ldquoFormation of polyesters con-sisting of medium-chain-length 3-hydroxyalkanoic acids fromgluconate by Pseudomonas aeruginosa and other fluorescentpseudomonadsrdquo Applied and Environmental Microbiology vol56 p 3360 1990

[9] A Ballistreri M Giuffrida S P P Guglielmino S Car-nazza A Ferreri and G Impallomeni ldquoBiosynthesis andstructural characterization of medium-chain-length poly(3-hydroxyalkanoates) produced byPseudomonas aeruginosa fromfatty acidsrdquo International Journal of Biological Macromoleculesvol 29 no 2 pp 107ndash114 2001

[10] M C Sin S N Gan M S M Annuar and I K P Tan ldquoChaincleavage mechanism of palm kernel oil derived medium-chain-length poly(3-hydroxyalkanoates) during high temperature


decompositionrdquo Polymer Degradation and Stability vol 96 no9 pp 1705ndash1710 2011

[11] S P Lim S N Gan and I K P Tan ldquoDegradation ofmedium-chain-length polyhydroxyalkanoates in tropical forestand mangrove soilsrdquo Applied Biochemistry and Biotechnologyvol 126 no 1 pp 23ndash33 2005

[12] G-Q Chen and Q Wu ldquoThe application of polyhydroxyalka-noates as tissue engineeringmaterialsrdquo Biomaterials vol 26 no33 pp 6565ndash6578 2005

[13] S F Williams D P Martin D M Horowitz and O PPeoples ldquoPHA applications addressing the price performanceissue I Tissue engineeringrdquo International Journal of BiologicalMacromolecules vol 25 no 1ndash 3 pp 111ndash121 1999

[14] M C Sin I K P Tan M S M Annuar and S N GanldquoCharacterization of oligomeric hydroxyalkanoic acids fromthermal decomposition of palm kernel oil-based biopolyesterrdquoInternational Journal of Polymer Analysis and Characterizationvol 16 no 5 pp 337ndash347 2011

[15] M C Sin S N Gan M S M Annuar and I K PTan ldquoThermodegradation of medium-chain-length poly(3-hydroxyalkanoates) produced by Pseudomonas putida fromoleic acidrdquo Polymer Degradation and Stability vol 95 no 12pp 2334ndash2342 2010

[16] J Yu and H Stahl ldquoMicrobial utilization and biopolyestersynthesis of bagasse hydrolysatesrdquo Bioresource Technology vol99 no 17 pp 8042ndash8048 2008

[17] R H Marchessault ldquoTender morsels for bacteria recent devel-opments inmicrobial polyestersrdquoTrends in Polymer Science vol4 no 5 pp 163ndash168 1996

[18] M C Sin I K P Tan M S M Annuar and S N Gan ldquoTher-mal behaviour and thermodegradation kinetics of poly(vinylchloride) plasticized with polymeric and oligomeric medium-chain-length poly(3-hydroxyalkanoates)rdquo Polymer Degradationand Stability vol 97 no 11 pp 2118ndash2127 2012

[19] I K P Tan K Sudesh Kumar M Theanmalar S N Ganand B Gordon III ldquoSaponified palm kernel oil and its majorfree fatty acids as carbon substrates for the production ofpolyhydroxyalkanoates in Pseudomonas putida PGA1rdquo AppliedMicrobiology and Biotechnology vol 47 no 3 pp 207ndash211 1997

[20] M C Sin I K P TanM SM Annuar and S N Gan ldquoKineticsof thermodegradation of palm kernel oil derived medium-chain-length polyhydroxyalkanoatesrdquo Journal of Applied Poly-mer Science vol 127 no 6 pp 4422ndash4425 2012

[21] S Y Hobbs and V H Watkins ldquoMorphology characterizationby microscopy techniquesrdquo in Polymer Blends D R Paul andC B Bucknall Eds John Wiley amp Sons New York NY USA2000

[22] D J Walsh J S Higgins and C Zhikuan ldquoThe compatibilityof poly(methyl methacrylate) and chlorinated polyethylenerdquoPolymer vol 23 no 3 pp 336ndash339 1982

[23] S George N R Neelakantan K T Varughese and S ThomasldquoDynamic mechanical properties of isotactic polypropylenenitrile rubber blends effects of blend ratio reactive compat-ibilization and dynamic vulcanizationrdquo Journal of PolymerScience Part B Polymer Physics vol 35 no 14 pp 2309ndash23271997

[24] K T Varughese G B Nando P P De and S K De ldquoMiscibleblends from rigid poly(vinyl chloride) and epoxidized naturalrubbermdashpart 1 Phasemorphologyrdquo Journal of Materials Sciencevol 23 no 11 pp 3894ndash3902 1988

[25] K P Menard Dynamic Mechanical Analysis A Practical Intro-duction CRC Press New York NY USA 1999

[26] A M Stephan T P Kumar N G Renganathan S PitchumaniR Thirunakaran and N Muniyandi ldquoIonic conductivity andFT-IR studies on plasticized PVCPMMA blend polymer elec-trolytesrdquo Journal of Power Sources vol 89 no 1 pp 80ndash87 2000

[27] S Rajendran M Ramesh Prabhu and M Usha Rani ldquoChar-acterization of PVCPEMA based polymer blend electrolytesrdquoInternational Journal of Electrochemical Science vol 3 pp 282ndash290 2008

[28] AMarcilla andM Beltran ldquoMechanisms of plasticizers actionrdquoin Handbook of Plasticizersin G Wypych Ed ChemTec Pub-lishing Toronto Canada 2004

[29] O Olabisi L M Robeson and M T Shaw Polymer-PolymerMiscibility Academic Press New York NY USA 1979

[30] L F Sin Polymeric Materials Characterization of MaterialsUsing Thermal Analysis Techniques Edited by S Radhakrishnaand A K Arof Narosa Publishing House New Delhi India1998

[31] S Thomas and A George ldquoDynamic mechanical properties ofthermoplastic elastomers from blends of polypropylene withcopolymers of ethylene with vinyl acetaterdquo European PolymerJournal vol 28 no 11 pp 1451ndash1458 1992

[32] L E Nielsen and R F LandelMechanical Properties of Polymersand Composites Marcel Dekker New York NY USA 2ndedition 1994

[33] S Radhakrishna and A K Arof Polymeric Materials NarosaPublishing House New Delhi India 1998

[34] T J Madera-Santana M Misra L T Drzal D Robledo andY Freile-Pelegrin ldquoPreparation and characterization of bio-degradable agarpoly(butylene adipateco-terephatalate) com-positesrdquoPolymer Engineering and Science vol 49 no 6 pp 1117ndash1126 2009

[35] R Hernandez J J Pena L Irusta and A Santamaria ldquoTheeffect of a miscible and an immiscible polymeric modifier onthe mechanical and rheological properties of PVCrdquo EuropeanPolymer Journal vol 36 no 5 pp 1011ndash1025 2000

[36] G Wypych Handbook of Plasticizers ChemTech PublishingToronto Canada 2004

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of



CeramicsJournal of


CompositesJournal of

NanoparticlesJournal of



International Journal of

Biomaterials


NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of


Nano

materials


Journal ofNanomaterials


is significant Therefore intense researches have been carriedout to seek alternative green plasticizer materials whichimpart low toxicity total or partial biodegradability andare economically and technically viable to substitute theconventional petrochemical-based plasticizers

Medium-chain-length polyhydroxyalkanoates (mcl-PHA) are bacterial polyesters comprised of six to fourteencarbon-chain-length monomers [8ndash10] which have biodegr-adable [11] biocompatible [12] and nontoxic [13] propertiesIn addition mcl-PHA can be synthesized from naturalrenewable resources such as plant oil [14] fatty acids [15] andagricultural wastes [16] Thus mcl-PHA fulfill all the desir-able traits of an alternative eco-friendly plasticizer materialThese bacterially produced polymers have sufficiently highmolecular weight in the range of 50000 to 300000 Dalton[17] As mcl-PHA also exhibit polar properties they havegreat potential to act as compatible plasticizer for PVC Inaddition possible entanglement between the PHA with PVCmay not allow for easy migration of the plasticizers out of theblended compounds Low molecular weight oligoesters canbe produced frommcl-PHA by thermal degradation processThese oligomeric hydroxyalkanoic acids possess favorableend groups and such fragments could be used as PVCplasticizers as well This is different from the conventionalpetrochemical-based plasticizers which are small moleculesthat intercalate into PVC and thusmay have limited residencetime in the PVC compound In the event of accidental ornatural migration from the blended compounds the PHAplasticizers would not be hazardous to human health andthe environment due to their nontoxic biodegradable andbiocompatible properties

In this work saponified palm kernel oil (SPKO)-derivedmcl-PHA and their low molecular weight oligoesters weremixed with PVC at the compositions of 25 and 5 parts perhundred parts (phr) of PVC through solution blending ThePVCPHA binary blends were solvent-casted and character-ized to study the polymer film morphology microstructurePVC-PHA interactions miscibility between the two poly-mers and viscoelastic properties of the PVCPHA polymerblends

2 Experimental Sections

21 Materials Poly(vinyl chloride) (PVC) with molecu-lar weight approximately 100000 gmolminus1 (BDH laboratoryreagent) was used throughout the experiments Mcl-PHAwere produced in a two-stage culture system which consistedof cell-growth phase and PHA-accumulation phase In thefirst phase the Pseudomonas putida PGA1 were grown innutrient broth (80 g Lminus1) a nutritionally rich medium toproduce high concentration of cells After 20 hours ofincubation the cells were harvested by centrifugation at8000 rpm for 30 minutes at 4∘C then washed with 085saline and transferred to the modified nitrogen-limiting M9medium [18] containing 05 (wv) saponified palm kerneloil (SPKO) [19] as the sole carbon source to induce PHAbiosynthesis by the cells The bacteria were further cultivatedin PHA production medium for 72 hours at 200 rpm and

30∘C The bacterial cells were then aseptically harvested bycentrifugationThe cells were washed twice with sterile 085saline and dried at 70∘C in a hot air oven to constant weightThe dried cells were washed with polar solvent to removeresidual carbon substrates and metabolic wastes from thebiomass by suspending them in 95 analytical grade ethanoland shaking for 30 minutes at 22 plusmn 1∘C and 160 rpm inthe orbital shaker incubator Oily residues and other polarlipids attached to the cells would dissolve in the alcoholwhich was decanted off The cells were then dried in ovenat 70∘C to constant weight Intracellular mcl-PHA wereextracted by suspending the dried cells in analytical gradechloroform and refluxed for 6 hours at 70∘C The PHA-chloroform solution was filtered through Whatman number1 filter paper to remove the cellular debris and the filtrate wasconcentrated by rotary evaporation The biopolymers werepurified by drop-wise addition of the extract into rapidlystirred methanol chilled with ice bath Further purificationwas carried out by redissolving the PHA in a small amountof chloroform and reprecipitating it in excess methanol Itwas then dried in a vacuum oven at 37∘C 06 atm for 48hours Lowmolecular weight PHA oligoesters were producedthrough mild thermal degradation of the polymer The mcl-PHA samples were thermally degraded at temperatures of170∘C At such temperature the heat-treated PHA (degPHA)is mainly composed of a mixture of oligomeric hydroxyacid fragments without terminal unsaturated fragments Thethermal degradation process was performed using similarprocedure as described earlier [15 18 20]

22 Gel Permeation Chromatography (GPC) Analysis of PHAand degPHA The number average molecular weight (119872

119899)

weight average molecular weight (119872119908) and polydispersity

index (PDI) of PHA and degPHA used in the blendingwere determined by gel permeation chromatography (GPC)analysis GPCwas performed using aWaters 600-GPC (USA)instrument equipped with Waters Styragel HR columns(78mm internal diameter times 300mm) connected in series(HR1 HR2 HR5E and HR5E) and a Waters 2414 refractiveindex detector Approximately 1000 120583L of 20mgmLminus1 poly-mer sample was eluted by THF at a flow rate of 1mLminminus1at 40∘C The instrument was calibrated using monodispersepolystyrene standards

23 Gas Chromatography (GC) Analysis of PHA and degPHAAnalysis of PHA and degPHAmonomeric compositions wasperformed using a GC 2014 Shimadzu (Japan) equippedwith a SGE forte GC capillary column BP20 (30m times025mm internal diameter times 025 120583m) (Australia) and aflame ionization detector (FID) In the GC analysis 10 120583Lof sample was injected by split injection with a split ratioof 10 1 using a SGE 100 120583L syringe Nitrogen was used asthe carrier gas at a flow rate of 3mLminminus1 The columnoven temperature was programmed from 120∘C for 2minat the start ramped up at a rate of 20∘Cminminus1 to 230∘Cand held at this temperature for 10min The temperaturesof injector and detector were set at 225∘C and 230∘C





8) 3-



14) and




25

and PdeSP25








6 Field





119892s of








119892has


119892can be


119892values



119870 =(119860 times 119864)

119871 (1)


119864 = 119870119904times119871

119860 (2)


119904is




and degPHA119878119875119870119874






6and C

8) compared to the









2119872119908

3PDI C6 C8 C10 C12 C14 C141



Cavities

10120583m

(a)

10120583m

(b)

10120583m

(c)

10120583m

(d)

10120583m

(e)

10120583m

(f)






5and




1726PHASPKO

PSP5

PSP5

PSP25

PSP25

1737

1741

PVC

PVC616

607

608

3000 2000 1500 1000 4500

0360

034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

A

(cmminus1)

(a)

0350034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

40000 3000 2000 1500 1000 4500

1727degPHASPKO

PdeSP5

PdeSP5

1738

PdeSP25

PdeSP25

1739

PVC

PVC616

610

609

A

(cmminus1)

(b)




17391198601426

) for PSP25 PdeSP

25 PSP5 and PdeSP

5



11986017391198601426







2ndash)


3) and methylene










(ppm)4 3 2

100

201

011

Polymer Polymer

H H

H Cl

C C120572120573

1

1

112

22

(a) PVC

CH3

CH2

O CH CH2 C

O

O CH CH2 C

O

O

CH3

CH2

CH

CH

CH2

100 216

218

890

342

(ppm)6 4 2

]n[

a

bc

d e

e d

c

b

a

(CH2)x

(CH2)6

(b) PHASPKO

100

133

067

019

6 4 2

(ppm)

(c) PSP25

6 4 2100

177

069

033

011

(ppm)

(d) PSP5

100

158

042

026

6 4 2

(ppm)

(e) PdegSP25

100

166

066

036

013

6 4 2(ppm)

(f) PdeSP5






119892


200000

150000

100000

50000

040 60 80 100 120

Stiffness

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PSP25

PSP5

(a)

200000

150000

100000

50000

040 60 80 100 120

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PdeSP25

PdeSP5

(b)


5and (b) PVC PdeSP

25 and PdeSP

5


119892


119892of 919∘C and



119892

834∘C for PSP25

and 119879119892 827∘C for PSP

5) and PVCdegPHA

(119879119892 809∘C for PdeSP

25and 119879


5) binary




5lower than PVCPHA

25and









25and








5(119864 172GPa for PSP

5and 119864 149GPa


25(119864 326GPa for

PSP25




4 Conclusions









Acknowledgment


References














































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials







8) 3-



14) and




25

and PdeSP25








6 Field





119892s of








119892has


119892can be


119892values



119870 =(119860 times 119864)

119871 (1)


119864 = 119870119904times119871

119860 (2)


119904is




and degPHA119878119875119870119874






6and C

8) compared to the









2119872119908

3PDI C6 C8 C10 C12 C14 C141



Cavities

10120583m

(a)

10120583m

(b)

10120583m

(c)

10120583m

(d)

10120583m

(e)

10120583m

(f)






5and




1726PHASPKO

PSP5

PSP5

PSP25

PSP25

1737

1741

PVC

PVC616

607

608

3000 2000 1500 1000 4500

0360

034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

A

(cmminus1)

(a)

0350034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

40000 3000 2000 1500 1000 4500

1727degPHASPKO

PdeSP5

PdeSP5

1738

PdeSP25

PdeSP25

1739

PVC

PVC616

610

609

A

(cmminus1)

(b)




17391198601426

) for PSP25 PdeSP

25 PSP5 and PdeSP

5



11986017391198601426







2ndash)


3) and methylene










(ppm)4 3 2

100

201

011

Polymer Polymer

H H

H Cl

C C120572120573

1

1

112

22

(a) PVC

CH3

CH2

O CH CH2 C

O

O CH CH2 C

O

O

CH3

CH2

CH

CH

CH2

100 216

218

890

342

(ppm)6 4 2

]n[

a

bc

d e

e d

c

b

a

(CH2)x

(CH2)6

(b) PHASPKO

100

133

067

019

6 4 2

(ppm)

(c) PSP25

6 4 2100

177

069

033

011

(ppm)

(d) PSP5

100

158

042

026

6 4 2

(ppm)

(e) PdegSP25

100

166

066

036

013

6 4 2(ppm)

(f) PdeSP5






119892


200000

150000

100000

50000

040 60 80 100 120

Stiffness

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PSP25

PSP5

(a)

200000

150000

100000

50000

040 60 80 100 120

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PdeSP25

PdeSP5

(b)


5and (b) PVC PdeSP

25 and PdeSP

5


119892


119892of 919∘C and



119892

834∘C for PSP25

and 119879119892 827∘C for PSP

5) and PVCdegPHA

(119879119892 809∘C for PdeSP

25and 119879


5) binary




5lower than PVCPHA

25and









25and








5(119864 172GPa for PSP

5and 119864 149GPa


25(119864 326GPa for

PSP25




4 Conclusions









Acknowledgment


References














































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials







119892has


119892can be


119892values



119870 =(119860 times 119864)

119871 (1)


119864 = 119870119904times119871

119860 (2)


119904is




and degPHA119878119875119870119874






6and C

8) compared to the









2119872119908

3PDI C6 C8 C10 C12 C14 C141



Cavities

10120583m

(a)

10120583m

(b)

10120583m

(c)

10120583m

(d)

10120583m

(e)

10120583m

(f)






5and




1726PHASPKO

PSP5

PSP5

PSP25

PSP25

1737

1741

PVC

PVC616

607

608

3000 2000 1500 1000 4500

0360

034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

A

(cmminus1)

(a)

0350034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

40000 3000 2000 1500 1000 4500

1727degPHASPKO

PdeSP5

PdeSP5

1738

PdeSP25

PdeSP25

1739

PVC

PVC616

610

609

A

(cmminus1)

(b)




17391198601426

) for PSP25 PdeSP

25 PSP5 and PdeSP

5



11986017391198601426







2ndash)


3) and methylene










(ppm)4 3 2

100

201

011

Polymer Polymer

H H

H Cl

C C120572120573

1

1

112

22

(a) PVC

CH3

CH2

O CH CH2 C

O

O CH CH2 C

O

O

CH3

CH2

CH

CH

CH2

100 216

218

890

342

(ppm)6 4 2

]n[

a

bc

d e

e d

c

b

a

(CH2)x

(CH2)6

(b) PHASPKO

100

133

067

019

6 4 2

(ppm)

(c) PSP25

6 4 2100

177

069

033

011

(ppm)

(d) PSP5

100

158

042

026

6 4 2

(ppm)

(e) PdegSP25

100

166

066

036

013

6 4 2(ppm)

(f) PdeSP5






119892


200000

150000

100000

50000

040 60 80 100 120

Stiffness

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PSP25

PSP5

(a)

200000

150000

100000

50000

040 60 80 100 120

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PdeSP25

PdeSP5

(b)


5and (b) PVC PdeSP

25 and PdeSP

5


119892


119892of 919∘C and



119892

834∘C for PSP25

and 119879119892 827∘C for PSP

5) and PVCdegPHA

(119879119892 809∘C for PdeSP

25and 119879


5) binary




5lower than PVCPHA

25and









25and








5(119864 172GPa for PSP

5and 119864 149GPa


25(119864 326GPa for

PSP25




4 Conclusions









Acknowledgment


References














































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






2119872119908

3PDI C6 C8 C10 C12 C14 C141



Cavities

10120583m

(a)

10120583m

(b)

10120583m

(c)

10120583m

(d)

10120583m

(e)

10120583m

(f)






5and




1726PHASPKO

PSP5

PSP5

PSP25

PSP25

1737

1741

PVC

PVC616

607

608

3000 2000 1500 1000 4500

0360

034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

A

(cmminus1)

(a)

0350034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

40000 3000 2000 1500 1000 4500

1727degPHASPKO

PdeSP5

PdeSP5

1738

PdeSP25

PdeSP25

1739

PVC

PVC616

610

609

A

(cmminus1)

(b)




17391198601426

) for PSP25 PdeSP

25 PSP5 and PdeSP

5



11986017391198601426







2ndash)


3) and methylene










(ppm)4 3 2

100

201

011

Polymer Polymer

H H

H Cl

C C120572120573

1

1

112

22

(a) PVC

CH3

CH2

O CH CH2 C

O

O CH CH2 C

O

O

CH3

CH2

CH

CH

CH2

100 216

218

890

342

(ppm)6 4 2

]n[

a

bc

d e

e d

c

b

a

(CH2)x

(CH2)6

(b) PHASPKO

100

133

067

019

6 4 2

(ppm)

(c) PSP25

6 4 2100

177

069

033

011

(ppm)

(d) PSP5

100

158

042

026

6 4 2

(ppm)

(e) PdegSP25

100

166

066

036

013

6 4 2(ppm)

(f) PdeSP5






119892


200000

150000

100000

50000

040 60 80 100 120

Stiffness

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PSP25

PSP5

(a)

200000

150000

100000

50000

040 60 80 100 120

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PdeSP25

PdeSP5

(b)


5and (b) PVC PdeSP

25 and PdeSP

5


119892


119892of 919∘C and



119892

834∘C for PSP25

and 119879119892 827∘C for PSP

5) and PVCdegPHA

(119879119892 809∘C for PdeSP

25and 119879


5) binary




5lower than PVCPHA

25and









25and








5(119864 172GPa for PSP

5and 119864 149GPa


25(119864 326GPa for

PSP25




4 Conclusions









Acknowledgment


References














































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




1726PHASPKO

PSP5

PSP5

PSP25

PSP25

1737

1741

PVC

PVC616

607

608

3000 2000 1500 1000 4500

0360

034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

A

(cmminus1)

(a)

0350034

032

030

028

026

024

022

020

018

016

014

012

010

008

006

004

002

000minus0010

40000 3000 2000 1500 1000 4500

1727degPHASPKO

PdeSP5

PdeSP5

1738

PdeSP25

PdeSP25

1739

PVC

PVC616

610

609

A

(cmminus1)

(b)




17391198601426

) for PSP25 PdeSP

25 PSP5 and PdeSP

5



11986017391198601426







2ndash)


3) and methylene










(ppm)4 3 2

100

201

011

Polymer Polymer

H H

H Cl

C C120572120573

1

1

112

22

(a) PVC

CH3

CH2

O CH CH2 C

O

O CH CH2 C

O

O

CH3

CH2

CH

CH

CH2

100 216

218

890

342

(ppm)6 4 2

]n[

a

bc

d e

e d

c

b

a

(CH2)x

(CH2)6

(b) PHASPKO

100

133

067

019

6 4 2

(ppm)

(c) PSP25

6 4 2100

177

069

033

011

(ppm)

(d) PSP5

100

158

042

026

6 4 2

(ppm)

(e) PdegSP25

100

166

066

036

013

6 4 2(ppm)

(f) PdeSP5






119892


200000

150000

100000

50000

040 60 80 100 120

Stiffness

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PSP25

PSP5

(a)

200000

150000

100000

50000

040 60 80 100 120

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PdeSP25

PdeSP5

(b)


5and (b) PVC PdeSP

25 and PdeSP

5


119892


119892of 919∘C and



119892

834∘C for PSP25

and 119879119892 827∘C for PSP

5) and PVCdegPHA

(119879119892 809∘C for PdeSP

25and 119879


5) binary




5lower than PVCPHA

25and









25and








5(119864 172GPa for PSP

5and 119864 149GPa


25(119864 326GPa for

PSP25




4 Conclusions









Acknowledgment


References














































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





(ppm)4 3 2

100

201

011

Polymer Polymer

H H

H Cl

C C120572120573

1

1

112

22

(a) PVC

CH3

CH2

O CH CH2 C

O

O CH CH2 C

O

O

CH3

CH2

CH

CH

CH2

100 216

218

890

342

(ppm)6 4 2

]n[

a

bc

d e

e d

c

b

a

(CH2)x

(CH2)6

(b) PHASPKO

100

133

067

019

6 4 2

(ppm)

(c) PSP25

6 4 2100

177

069

033

011

(ppm)

(d) PSP5

100

158

042

026

6 4 2

(ppm)

(e) PdegSP25

100

166

066

036

013

6 4 2(ppm)

(f) PdeSP5






119892


200000

150000

100000

50000

040 60 80 100 120

Stiffness

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PSP25

PSP5

(a)

200000

150000

100000

50000

040 60 80 100 120

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PdeSP25

PdeSP5

(b)


5and (b) PVC PdeSP

25 and PdeSP

5


119892


119892of 919∘C and



119892

834∘C for PSP25

and 119879119892 827∘C for PSP

5) and PVCdegPHA

(119879119892 809∘C for PdeSP

25and 119879


5) binary




5lower than PVCPHA

25and









25and








5(119864 172GPa for PSP

5and 119864 149GPa


25(119864 326GPa for

PSP25




4 Conclusions









Acknowledgment


References














































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




200000

150000

100000

50000

040 60 80 100 120

Stiffness

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PSP25

PSP5

(a)

200000

150000

100000

50000

040 60 80 100 120

Stiff

ness

(Nm

)

Temperature (∘C)

PVC

PdeSP25

PdeSP5

(b)


5and (b) PVC PdeSP

25 and PdeSP

5


119892


119892of 919∘C and



119892

834∘C for PSP25

and 119879119892 827∘C for PSP

5) and PVCdegPHA

(119879119892 809∘C for PdeSP

25and 119879


5) binary




5lower than PVCPHA

25and









25and








5(119864 172GPa for PSP

5and 119864 149GPa


25(119864 326GPa for

PSP25




4 Conclusions









Acknowledgment


References














































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






5(119864 172GPa for PSP

5and 119864 149GPa


25(119864 326GPa for

PSP25




4 Conclusions









Acknowledgment


References














































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






































CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



viscoelastic, spectroscopic, and microscopic characterization of novel bio-based plasticized...

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