francys k. v. moreira, ph.d. national nanotechnology laboratory for agribusiness (lnna) embrapa...
TRANSCRIPT
Francys K. V. Moreira, Ph.D.National Nanotechnology Laboratory for Agribusiness (LNNA)
Embrapa Instrumentation, São Carlos (SP), Brazil
Continuous casting: a soft processing approach to fabricate polysaccharide-based bioplastics
Biopolymers & Bioplastics-2015 “Bio World Innovation: Smart, green and environmentally sustainable biopolymers
BackgroundNon-biodegradable plastics – Versatile
materials
Images from Internet.
BackgroundNon-biodegradable plastics – The
“dark side”
Images from Internet.
Background
4
Celullose
Chitin
Pectins
Hemicelluloses
Starch
Carragenan
Alginates
Polysaccharides
Green raw-materials for
plastic production
BackgroundConsiderable potential for short time
applications
Biodegradable plastic
wraps
Edible films
Fully biodegrada
bleRelatively cheap
Neutral and hydro-soluble Abundant as a natural
resourceImages from Internet.
Background
Blow Molding Extrusion Single Screw Extrusion Twin Screw Extrusion Fiber Spinning Dry Spinning Melt Spinning Wet Spinning Filament Winding Film Blowing Injection Molding Mixing and Compounding Batch Intensive Mixing Twin Screw Extrusion Pultrusion Reaction Injection Molding Spin Coating Transfer Molding.
*http://www.polymerprocessing.com/operations/index.html
Polymer Processing Methods
Images from Internet.
BackgroundCasting as a processing method for biodegradable polymers
BackgroundCasting is not applicable to large scale production
Blow Molding Extrusion Fiber Spinning Mixing and Compounding Pultrusion Transfer Molding
Injection molding.
Casting
Image from Internet.
CONTINUOUS CASTING AS A SCALABLE-UP METHOD FOR POLYSACCHARIDE FILM PRODUCTION
Background
Low temperatures involved (90 °C);Precise control of film thickness;Short time-related process (4 min);Applicable for industrial production of biodegradable films.
CONTINUOUS CASTING
To determine the suitability of the continuous casting as a processing method for the production of bioplastic films from polysaccharides.
GENERAL OBJECTIVE
Study of different
polysaccharides;
Rheology of
polysaccharide
solutions;
Delineation of
processing conditions;
Mechanical
characterization.
Sample* Concentration range (wt.%)
Pectin 4 - 10
Chitosan 5 - 8
Hydroxypropyl Methyl-cellulose (HPMC) 4 - 12
Carboxymethyl-cellulose (CMC) 1-2
Corn starch 4-10
Alginate_Na+ 1 - 5
Carragenan 1-4
Experimental – Polysaccharide samples
*HPMC: Methocel E19FG (Dow); Pectin: Citrus Pectin USP-B (CKPelco); Chitosan (Polymar); CMC: Murta Ing.; Starch: CascoTM (Ingredion); Alginate: (GastronomyLab): Carragenan GENUGEL® (CPKelco)
Aqueous polysaccharide solutions used in the CC.
Experimental – Labcoater casting unit*
*KTF Devices: (1) – Substrate roll; (2) Foulard of Transport; (3) Coating device; (4) IR pre-dryer; (5) First hot air drying chamber; (6) Foulard of lamination; (7) Lamination roll; (8) Second hot air drying chamber; (9) Collecting roll.
ExperimentalMathis KTF-B Coating Device
2 - Doctor Knife Type B
1 - Substrate
3 - Comparative
clocks (± 0.001 mm)
Continuous casting - Step 1: Casting
Continuous casting - Step 1: Casting
Continuous casting - Step 2: Drying
Continuous casting - Step 3: Rolling up
CONTINUOUS CASTING
- HIGHLIGHTED RESULTS-
HIGHLIGHTED RESULTS
Rheological Aspects
IDEAL UNDESIRABLEUNDESIRABLE
Low viscosity High viscosity Too high viscosity
Molecular mass, Solid content
HPMC 2 wt.% PEC 8 wt.% CMC 2 wt.%
LiquidLiquid Gel
HIGHLIGHTED RESULTSRheological Aspects
-20 -10 0 10 20 30 40 50 60 70 80 90 100 110
0
2
4
6
8
10
12
2 wt.%4 wt.%
6 wt.%
10 wt.%
Vis
cosi
ty (P
a s)
Shear rate (s-1)
HPMC 12 wt.%
Flow curves (25 °C) of aqueous HPMC solutions with different concentrations.
IDEAL
-20 -10 0 10 20 30 40 50 60 70 80 90 100 110
0
20
40
60
80
100
120
HPMC 12 wt.%
PEC 8 wt.%
Vis
cosi
ty (P
a s)
Shear rate (s-1)
Rheological Characterization
HIGHLIGHTED RESULTS
Comparison of flow curves (25 °C) between a HPMC solution (12 wt.%) and pectin solution (8 wt.%)
0 100 200 300 400 500-200
0
200
400
600
800
1000
1200
1400
1600
1800
G''>>G'
HPMC 12 wt.%
Loss modulus, G''
Mod
ulus
(P
a)
Angular frequency (rad s-1)
Storage modulus, G'
HIGHLIGHTED RESULTSRheological Characterization
Frequeny sweep at 25 °C: Dependence of storage modulus (G’) and loss modulus (G’’) on the angular frequence for an aqueous HPMC solution (12 wt.%).
HIGHLIGHTED RESULTS
Sample Concentration (wt.%)
Temperature (°C)
Processing speed*
(m min-1)
Film thickness
(μm)**
Coef. Of variation
(%)***
Pectin 8 130 0.15 14 - 50 4
Chitosan 5 120 0.15 15 - 80 9
HPMC 12 130 0.12 30 - 100 8
CMC 1.55 140 0.08 20 - 40 18
Starch 5 100 0.12 20 - 30 9
Alginate 1.5 - 2 140 0.08 20 - 40 17
Carragenan 2 140 0.08 20 - 40 17
Summary of the best CC conditions for some polysaccharides
*Maximum value; ** Wet solution layer thickness = 0.05 - 0.2 mm;***n = 10.
HIGHLIGHTED RESULTSMechanical Characterization
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34
0
5
10
15
20
25
30
35
40
0.20 mm
0.125 mm
0.1 mm
0.175 mm
For
ce (N
)
Deformation (mm)
Chitosan, 5 wt.%, Acetic acid 2 v.%
0.150 mm
Force (N) – deformation (mm) curves of chitosan films with varying thickness.
19 μm
25 μm
34 μm
45 μm
42 μm
HIGHLIGHTED RESULTSSummary of Mechanical Properties*
Polymer Elastic Modulus (MPa)
Tensile Strength (MPa)
Elongation at Break (%)
Pectin 3000 - 4000 20 - 100 2 - 4
Chitosan 1900 - 3000 20 - 50 2 - 18
HPMC 1500 - 2000 30 – 40 4 - 10
CMC 1000 - 1200 6 – 17 6 - 20
Starch 1000 - 1200 15 - 20 2 - 5
LLDPE** 130 - 520 9 – 20 100 - 1200
LHDPE** 60 - 290 10 - 60 N.D.
Data were collected following the ASTM D 882 protocol, cross-head speed of 10 mm min-1* , load cell of 10 Kgf. A. Prasad, Polymer Data Handbook, J. E. Mark, Ed. Oxford University Press, Oxford, 1999, 524.
Concluding Remarks
Continuous casting could be a suitable method for the production of bioplastic films at large scale from any type of polysaccharide;
Homogeneous polysaccharide film sheets can be properly fabricated only from liquid- or weak gel-like formulations. Formulations with high solid content are always desirable;
The mechanical parameters of the polysaccharide-based bioplastic films can be easily tuned by setting the thickness during the continuous casting process.
CONTINUOUS CASTING
- OUTLOOKS-
POLYMER PROCESSING OF DELICATE COMPOUNDS
Dr. Tara McHugh, leading scientist in fruit puree edible films for food packaging (WRRC-ARS/USDA).
POLYMER PROCESSING OF DELICATE COMPOUNDS
Nori
Watermelon
Passion fruit
Red guava
ASTM-D638 Type I specimens for red guava, passion fruit, and watermelon-based bioplastics.
INTENSIFICATION OF BIONANOCOMPOSITES’
PROPERTIES
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.50
10
20
30
40
50
60
70
80
Tens
ile S
treng
th (M
Pa)
Mg0.75
Al0.25
(OH)2 (wt.%)
Bench Labcoater
Tensile strength evolution of pectin-hydrotalcite bionanocomposites made by continuous (CC) and bench (BC) casting. Tensile tests were carried out using an Instron Machine at speed of 25
mm min-1.*
Bench casting vs. continuous casting
*Moreira, F. K. V., Materials Science and Engineering. Thesis (2014), Federal University of São Carlos, Brazil
Luiz H. C. Mattoso
Tara McHugh
Don Olson
Roberto Bustillos
Caio Gomide
Marcos Lorevice
Acknowledgments
Scientific Staff
Contacts: Francys Moreira ([email protected])
Financial Support
EMBRAPA
FAPESP (Project no 2012/87216-0)
FINEP/MCT
CNPq (CNPq/Sisnano 402287/2013-4)
CAPES