Biodegradable Polymer Nanocomposite Films &

Coatings for Barrier Applications

Prof. Funda TIHMINLIOGLU

İzmir Institute of Technology,

Chemical Engineering Department, İzmir, TURKEY

16th International AMETEK MOCON

Technical Conference 14 th of Febrıuary 2019

OUTLINE Polymer usage

Biodegradable polymers

Coating applications

Polymer nanocomposites

Silicate layered polymer nanocomposites

Permeability properties of biodegradable polymers

Gas and water vapor

Conclusion

Polymer consumption > 335 million tonnes/year *

Poor biodegradabilityRecycle problems

Waste disposal

Environmental concern and regulation

Biodegradable polymer usage

Thermoplastics

POLYMER USAGE

* Plastics Europe Facts and Figures 2017

BIODEGRADABLE POLYMERS

*(Siracusa,2008)

o Degrade by the enzymaticaction of microorganisms such asbacteria, fungi, and algae or byhydrolysis

o non-toxic

o Mainly used in

o Medical

o Textile

o Packaging

o Coating

Life cycle of BPs*

PBS PBSL

PCL PBST

PBSAT PBSA

PTMAT

PCBS

PE PP

PET PBT

PA6,66 PVC

PUR ABS

Epoxy resin

Synthetic rubber

BIOBASED vs BIODEGRADABILITYB

IOD

EG

RA

DA

BIL

ITY

BIOBASED RAW MATERIAL

Starch blends(with biodegradable fossil-based copolymers )

PLA blends(with biodegradable fossil-based copolymers )

Starch blends (with polyolefins)PA610PTT (from biobased 1,3-PDO )PET PVC (from biobased ethylene)Epoxy resin(from biobased glycerol)ABS SBR PBT( biobased succinic acid )

TPSStarch blends(with biobased and biodegradable copolymers)

PLA PHA PO3G Zein

Cellulose acetate

Biobased PE

Biobased PB

PA 11

NO

N-B

IOD

EG

RA

DA

BLE

FU

LLY

BIO

DEG

RA

DA

BLE

FULLY FOSSIL-BASED

PARTIALLY BIOBASED FULLY BIOBASED

5

*european-bioplastics.org

COATING APPLICATIONSMEDICAL DEVICES

Drug release

Biocompability

PAPER

Mechanical properties

Barrier propertiesHISTORICAL MONUMENTS

Protection studies

Barrier properties

FOOD

Antimicrobial activity

Food degradation

FOOD PACKAGING

“Food packaging deals with preparation of foodproducts for transport, distribution, storage and retailing end use”*

➥ Barrier to oxygen and water vapor

➥ Mechanically strong

➥ Good appearance, transparency

➥ Environment friendliness

Multilayer Films

Polymers are widely used in food packaging

* UK Institute of Packaging

PHYSICAL PROPERTIES

Physical properties not enough

for industrial usage

Mechanical

Barrier

High hydrophilicity

Processibility*(Weber, 2000)

High cost

POSSIBLE SOLUTIONS Blending with other polymers

Reinforcements Nanoparticles

Nanosilicates(N-Silicate)

Nanoclays (MMT)

Carbon Nanotubes

Nanotitaniumoxides

Desirable properties of biodegradable films& coatings can be further

improved by employing layered silicate nanocomposites

POLYMER NANOCOMPOSITESNew type of materials utilizing enhanced interaction between

filler and polymer matrix

Improved Properties Disadvantages

Mechanical Properties Dispersion

difficulties

Barrier Properties Optical issues

Dimensional stability Viscosity increase

Synergistic flame retardant

additive

Sedimentation

Thermal properties

Chemical resistance

o Large interfacial area

per volume

o High aspect ratio

Strong interactions

Nanoparticle Polymer

LAYERED SILICATE NANOCOMPOSITES

● High aspect ratio (α=70-1000nm/~1nm)

● Exist in stacks

● Enormous surface area

● Stack openings can be increased

by organomodification! brings in compatibility with

hydrophobic polymers

W

L

by sonication/shear

Aspect ratio (α): L/W

Montmorillonite is the most widely used

BARRIER PROPERTIES

0

0.2

0.4

0.6

0.8

1

1.2

0 0.01 0.02 0.03 0.04 0.05

LS Volume Fraction

Re

lati

ve

Pe

rme

ab

ility

α=1000

α=100

α=10

α=1

High aspect ratio and geometry of layered silicates form tortuous

path for diffusing molecules when effectively dispersed in the matrix

As the effective aspect ratio

of LS in the matrix increases, the

level of barrier improvements

increase

Layered Silicate Nanocomposites

LS

LS

LSpolymer

composite

W

LP

P

)2

(1

1

Permeability depends on:

Dimension of dispersed layer silicate particles

Dispersion of layered silicate in polymer matrix

Micro Nano

WATER VAPOR PERMEABILITY

MOCON PERMATRAN-W

model 3/33

ASTM F1249

37.80C – 90% RH

ASTM D3985230C – 0% RH

O2 AND CO2 GAS PERMEABILITY

ThicknessP

onRateTransmissityPermeabili

GAS BARRIER

O2 permeability of PLA films decreased by 53% for 5wt% OMMT loading

CO2 permeability of PLA films decreased by 27% for 5wt% OMMT loading

* Hale Oğuzlu-Chemical Eng.Master Thesis (IZTECH, 2011)

Polylactide Nanocomposites Films*

0

0.2

0.4

0.6

0.8

1

1.2

0 2 4 8 10

Re

lati

ve

P

erm

ea

bil

ity

Clay content (%)

For oxygen

For carbon dioxide

GAS BARRIER

✔ O2 permeability

of chitosan films

decreased by 87%

for 4 wt% OMMT

✔CO2 permeability

of chitosan films

decreased by 50%

for 4 wt% OMMT

loading

Clay content Permeability

Chitosan Nanocomposites Films*

LS

LS

LSpolymer

composite

W

LP

P

)2

(1

1

Relative

permeability)

BARRIER PERFORMANCE OF CORN ZEIN NANOCOMPOSITE

0

0.2

0.4

0.6

0.8

1

1.2

PPZ CLO10A-1% CLO10A-3% CLO10A-5% CLO10A-7.5%

Sample

Rela

tive P

erm

eab

ilit

y

WVP

Oxygen Perm

✔Both OP and WVP decreased due to increased tortuosity

* Onur Ozcalik , Funda Tihminlioglu ‘Barrier properties of corn zein nanocomposite coated polypropylene films for food packaging applications’,

Journal of Food Eng.,114, 2013

Optimum coating

composition

0

0.2

0.4

0.6

0.8

1

1.2

PP PP-CZ PP-CZNC-1% PP-CZNC-3% PP-CZNC-5% PP-CZNC-7.5%

Rela

tive O

xyg

en

Perm

eab

ilit

y

0

0.2

0.4

0.6

0.8

1

1.2

Rela

tive O

xyg

en

Perm

eab

ilit

y

PP-CZNC

CZNC

GAS BARRIER

✔ 5wt %OMMT loading

decreased OP of CZNC

layers by 65%

✔ Oxygen barrier of coated

PP films increased by 4

times

PP films coated with Corn zein Nanocomposites

*Tihminlioglu et al, 2011 «Effect of corn-zein coating on the mechanical properties of polypropylene packaging

films « Journal of Applied Sci.

*Tihminlioglu, et al, 2010 « Water vapor and oxygen-barrier performance of corn-zein coated polypropylene

films « Journal of Food Engineering,

n

i i

i

P

L

P

L

1L: Thickness of layer

P: Permeability of layer

0

0,2

0,4

0,6

0,8

1

1,2

0 2 4 8 10Clay Content (%)

Re

lati

ve

Wa

ter

Va

po

r

Pe

rme

ab

ilit

y

✔ WVP of chitosan films decreased by 20% for 4wt% OMMT loading

WATER VAPOR BARRIERChitosan Nanocomposites Films

* (Oguzlu Hale, Tihminlioglu,Funda, , Preparation and Barrier Properties of Chitosan-Layered Silicate

Nanocomposite Films, Macromolecular Symposia, 298,2010 )

0

0,5

1

1,5

2

2,5

3

3,5

4

35 40 45 50 55 60 65 70 75 80 85 90

RH(%)

WV

P(g

/m2 d

ay

mm

Hg

)mm

Clay content Permeability

✔97% decrease in WVP of PL65-

10A nanocomposite with 10% clay

loading *

✔53% and 47% decrease in WVP of

GF-10A & GF-93A nanocomposites for

7% and 5% clay loadings

*Hale Oğuzlu-Chemical Eng Master Thesis (IZTECH, 2011)

*Akın et al , 2018 - Book chapter in Advances in Nanostructured Composites

WATER VAPOR BARRIER

0.000

0.500

1.000

1.500

2.000

2.500

3.000

3.500

0 1 2 5 7 10

WV

P(g

/m2d

ay

mm

Hg

)m

m

Clay Content (%)

PL65-10A

WATER VAPOR BARRIER

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 1 3 5

Filler Content (%)

Rela

tive W

ate

r V

ap

or

Perm

eab

ilit

y

OMMT

MMT

Corn Zein

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 3 5

Filler Content (%)

Rela

tive W

ate

r V

ap

or

Perm

eab

ilit

y

OMMT-SonicationOMMT-StirringCorn Zein

Effect of NC Preparation and Organomodification of MMT

✗ Higher WVP for

unmodified clay samples

✗ Effect of processing on

WVP

* Onur Özçalık – Master Thesis (IZTECH, 2010)

TEMPERATURE DEPENDENCY OF WVP

Temperature oC

5 10 15 20 25 30 35 40 45

WV

P

((g

r/m

2 d

ay/m

m H

g)m

m)

0.00

0.01

0.02

0.03

0.04

0.05

PHB-S-N

PHB-S-1

PHB-S-2

PHB-S-3

Temperature oC

5 10 15 20 25 30 35 40 45

WV

P

((g

r/m

2 d

ay

/mm

Hg

)mm

)

0.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035

PHBHV-S-N

PHBHV-S-1

PHBHV-S-3

PHBHV-S-5

Barrier Performance @ 10,

20, 30, 40 oC @ 90% RH

Temperature WVP

Exponential increase in WVP

PHB-S PHBHV-S

Polyhydroxybutyrate and Polyhydroxybutyrate co valerate copolymer

*Akin O.Tihminlioglu F., J Polym Environ (2018) 26:1121–1132

ACTIVATION ENERGY OF WVP

-6.50

-6.00

-5.50

-5.00

-4.50

-4.00

-3.50

-3.00

-2.50

0.0031 0.0032 0.0033 0.0034 0.0035 0.0036

ln(P

)

((gr/

m^2

day

/mm

Hg)m

m)

1/T (K^-1)

PHB-S-N

PHB-S-1

PHB-S-2

PHB-S-3

Sample R-Squared Slope Ea(kj/mol)

PHB-S-N 0.99830 -6350.1 52.79

PHB-S-1 0.98880 -5849.9 48.64

PHB-S-2 0.98940 -6147.1 51.11

PHB-S-3 0.98950 -6992.5 58.14

RTE

o

a

ePP

oa P

RT

EP lnln

Logarithmic

Form

At low amount of

Cloisite 10A, Ea (Energy

that penetrant molecule

owing) decreases.

At higher amount of

Closite 10 A samples Ea

increases

*Akin O.Tihminlioglu F., J Polym Environ (2018) 26:1121–1132

PERMEABILITY MODELS

CP

C

cM

M

1

1

1

Volume FractionDiffusion Direction

Model LS Array Formula Assumptions

2D, rectangular platelets, random

array, platelets align normal to

diffusion direction

2D, rectangular platelets, random

array, platelets align in different

directions to diffusion

2D, rectangular platelets, regular

array, platelets align normal to

diffusion direction

2D, rectangular platelets, regular

array, platelets align normal to

diffusion direction

Nielsen

Cussler (random)

Cussler (regular)

Bharadwaj

21

1

0

P

P

20 )3

1(

1

P

P

4

)(1

12

0

P

P

)2

1(

23

21

)1(

0

SP

P

0

0.2

0.4

0.6

0.8

1

1.2

0 0.02 0.04 0.06 0.08

Rel

ati

ve

Per

mea

bil

ity

Volume Fraction

exp

Nielsen

Cussler Regular

Cussler random

Bharadwaj S=-0.5

Bharadwaj S=1

Bharadwaj S=0

Assumption: good level dispersion of silicate layers WVP OP &CP permeability data

0

0.2

0.4

0.6

0.8

1

1.2

0 0.01 0.02 0.03 0.04 0.05

Rel

ati

ve

Per

mea

bil

ity

Volume Fraction

exp

Nielson

Cussler regular

Cussler random

Bharadwaj S=-1/2

Bharadwaj S=1

Bharadwaj S=0

PL65-10A have better level of dispersion

PERMEABILITY MODELS

PROTECTION STUDIES

Ocak Y., Sofuoflu A., Tihminlioglu F. Boke H. 2009, Progress in Organic Coatings

Coated

uncoated

coated

uncoated

The increase of the water repellency from the stone surface is

the most important issue on the protection of stone.

WETTABILITY

Contact angle Degree of wetting

θ=0o Perfect wetting

0o<θ<90o High wettability

90o≤θ<180o Low wettability

θ=180o Perfectly non-wetting

KSV Attension Theta

Optical Tensiometer

Sample Name*

Av. Contact Angle (θo)

Sample Name**

Av. Contact Angle (θo)

Sample Name***

Av. Contact Angle (θo)

PLA 78.31±1.58 PHB 75.93 ±1.53 PPZ 54.25±0.82

PLA/C-1% 78.85±3.87 PHB/C-1% 81.41 ±2.90 PP-CZNC-1% 56.06±1.45

PLA/C-2% 78.93±1.20 PHB/C-2% 76.27 ±2.34 PP-CZNC-3% 56.62±1.93

PLA/C-5% 83.72±2.80 PHB/C-3% 74.73 ±1.54 PP-CZNC-5% 61.13±0.89

PLA/C-7% 83.37±1.55 PHB/C-5% 73.91 ±1.77 PP-CZNC-7.5% 61.66±1.68

PLA/C-10% 81.00±1.95 PHB/C-7% 69.84 ±1.04 PP-CZNC-15% 63.12±4.89

WETTABILITY

* Hale Oğuzlu-Master Thesis (IZTECH, 2011)

**Okan Akın-Master Thesis (IZTECH, 2012)

***Onur Özçalık – Master Thesis (IZTECH, 2010)

OPTICAL PROPERTIES

Color of the films are critical in most food packaging and coating

applications

222baLE Hunter Values

ΔE<3

OPTICAL PROPERTIES

Sample *Total Color

Difference(∆E) Sample * * Total Color Difference(∆E)

PLA Ref. PHB Ref.

PLA/C1% 0.32±0.11 PHB/C1% 1.29±0.30

PLA/C2% 0.36 ± 0.11 PHB/C2% 0.70±0.11

PLA/C5% 1.12 ±0.21 PHB/C3% 0.94±0.35

PLA/C7% 0.55 ±0.09 PHB/C5% 0.76±0.05

PLA/C10% 0.25 ±0.06 PHB/C7% 0.51±0.29

Polylactide & Polyhydroxybutrayte Nanocomposites Films

✔ Effective dispersion of OMMT in polymer matrix resulted

insignificant color changes to naked eye (ΔE<3)

Permeability properties of biodegradable polymer nanocomposite

films and coatings for barrier applications were investigated.

Barrier to O2 and water vapor was improved successfully by

incorporation of appropriate layered silicate in polymer matrix.

Unmodified montmorillonite loaded samples and stirred coatings

showed less improvements compared to modified clay samples due to

poorer compatibility with hydrophobic polymers.

Nanocomposite film/coating applications may also lead to significant

improvements in many properties (mechanical, thermal, biodegradation

surface without altering optical properties.

Nanocomposites of biodegradable polymers and their films&coatings

can be a good solution to utilize their excellent barrier properties in

packaging applications.

CONCLUSIONS

Thanks for yourAttention…

Funda TIHMINLIOGLUProfessor of Chemical Engineering

İzmir Institute of Technology

İzmir , Turkey

fundatihminlioglu@iyte.edu.tr