BIOBIO­­BASED Nano/Micro BASED Nano/Micro COMPOSITE MATERIALS: COMPOSITE MATERIALS: COMPOSITE MATERIALS: COMPOSITE MATERIALS: 

CHALLENGES and OPPORTUNITIESCHALLENGES and OPPORTUNITIES

Professor Lawrence T. DrzalProfessor Lawrence T. Drzal

Dept of Chemical Engineering and Materials ScienceDept of Chemical Engineering and Materials ScienceComposite Materials and Structures CenterComposite Materials and Structures Center

2100 Enginee ing B ilding2100 Enginee ing B ilding2100 Engineering Building2100 Engineering BuildingMichigan State UniversityMichigan State UniversityEast Lansing, MIEast Lansing, MI--4882448824

DRZAL@EGR.MSU.EDUDRZAL@EGR.MSU.EDU

BioPolymers come from…BioPolymers come from…

SugarSugar FermentationFermentation

Future:

Lactic Acid

Mo o eMo o eFuture: Monomer Monomer ProductionProduction

LactideLactide

Polymer Polymer ProductionProductionPolymerPolymer ProductionProduction

PLA

Polymer Polymer ConversionConversion

Ref.: B. S. Glasbrenner (Natureworks) Antec 2005 Ref.: B. S. Glasbrenner (Natureworks) Antec 2005

BioBio­­Based Polymers Based Polymers Commercial ProductsCommercial Products­­ Commercial ProductsCommercial Products

Poly(lactic acid)Poly(lactic acid) ‘‘Natureworks’Natureworks’ ((Cargill) & Mitsui ChemicalsCargill) & Mitsui ChemicalsStarch plasticsStarch plastics Novamont, National StarchNovamont, National StarchCellulosic PlasticCellulosic Plastic Eastman ChemicalEastman Chemical FromFromCellulosic PlasticCellulosic Plastic Eastman ChemicalEastman ChemicalBacterial polyesterBacterial polyester ‘Telles’ Metabolix‘Telles’ Metabolix--ADMADM

Aliphatic / aliphaticAliphatic / aliphatic--aromatic copolyesteraromatic copolyester

RenewablesRenewables

p pp p p yp yEaster BioEaster Bio EastmanEastmanBiomax DuPontBiomax DuPontEcoflex BASFEcoflex BASFBAK BayerBAK Bayer

FromFromPetroleumPetroleum

BAK BayerBAK BayerBionolle Showa High PolymerBionolle Showa High Polymer

Petroleum blend with Renewable ResourcesPetroleum blend with Renewable Resources FromFromSorona (DuPont)Sorona (DuPont)BioBio--based polyurethanesbased polyurethanesBioBio--based Epoxy/Polyesterbased Epoxy/Polyester

FromFromBioBio--+ Petro+ Petro

Ref. A. K. Mohanty, M. Misra, G. Hinrichsen, Macromol. Mater. Sci. Eng. 276/277, 1-24 (2002)

BioBio­­Based Structural Polymer Composites Based Structural Polymer Composites  th  M t i l  f  th  21 th  M t i l  f  th  21stst C t !C t !are the Materials for the 21are the Materials for the 21stst Century!Century!

• Advantages of Bio-Based Polymers:– Biodegradable, made from renewable, sustainable Resources– Very Good processability, Good mechanical properties– Eco-friendly

• Shortcomings:• Shortcomings:– Biodegradable, Brittle, Water Sensitive, Low HDT– Thermally Degrade, inherent variability in composition,

properties, quality– primarily for textiles, packaging and disposables

• Bio-based Structural polymer composite materials have both properties and performance:

Bi C it M t i l– Bio-Composite Materials• Addition of reinforcing fibers or nanoparticles to improve mechanical,

thermal properties and durability– Control of reinforcement orientation and concentration

‘optimizes’ properties‘optimizes’ properties– Adding biobased reinforcing fibers reduces cost

REINFORCEMENTSREINFORCEMENTS

Motivation for BioFibersWeight savings

1.3

2.62

3

4

y, g

/cm

3

Cost comparison

70

6080

100120

Cen

ts/lb

.

1.3

0

1

Glass Biofiber

Den

sity

25

0204060

Glass Biofiber

U.S

. C

Energy savings

23,500

15 00020,00025,00030,000

/1 lb

. fib

er

6,500

05,000

10,00015,000

Glass Kenaf

E (B

TUs)

/

Biodegradable Biodegradable M t i lM t i l

- Mechanical PERFORMANCE- Biodegradable and Recyclable- CO2 Neutral & Sequesterization

MaterialsMaterials

2 q

BIOFIBER REINFORCEMENTS from BIOFIBER REINFORCEMENTS from BIOFIBER REINFORCEMENTS from BIOFIBER REINFORCEMENTS from PLANTSPLANTS

Non-woodBioFibers

StrawBioFibers

WoodBioFibers

CelluloseNano-whiskers

BAST LEAF SEED/FRUIT

Corn,Wheat,Rice Straw Wood

& Non-wood

Kenaf, Flax,Jute,Hemp, Cotton, Coir

& Non-woodFibers Through

AFEX

Grasses

Sisal, Henequen,

Cotton, Coir

ConiferousD idPineapple Leaf Fiber Deciduous

Hierarchical StructureHierarchical Structure­­Bast Fiber Bast Fiber 

microfibril

nanowhisker

H. L. BOS, et al., J. MATER SCI 39 (2004) 2159 – 2168

BioBio­­FIBERSFIBERSFLAXFLAX “Industrial” HEMP“Industrial” HEMP KENAFKENAF

COICOIRR

JUTEJUTE HENEQUENHENEQUEN

Woven Woven JUTE ClothJUTE Cloth

BioComposite Manufacturing BioComposite Manufacturing Process Requirements Process Requirements 

WOODWOOD GrassGrassCorCor• Preserve BioFiber Mechanical Properties

– minimize attrition – minimize mixing degradation

P i t t 200 C– Processing temperature <200oC• High Degree of BioFiber Dispersion and

Wettability• Maximize BioFiber Volume Fraction• Control BioFiber Orientation• Control BioFiber Orientation• High Speed• Low Cost• Environmentally Benign

No organic solvent – No organic solvent – Water process or Dry process

• Low energy consumption

K f Pl t Fib /S  Pl ti  Bi itK f Pl t Fib /S  Pl ti  Bi itKenaf Plant Fiber/Soy Plastic BiocompositesKenaf Plant Fiber/Soy Plastic Biocomposites

6 2

11

9

12

MPa

)

370

2892.7

2.0250

300

350

400

th (J

/m)

2

2.5

3

n Im

pact

m

m)

Impact strengthFiber length on impact surface

2.9 3

4.65.9 6.2

3

6

Mod

ulus

(M

50

125

184

920.8

1.2

0.750

100

150

200

250

mpa

ct s

tren

g

0.5

1

1.5

ber l

engt

h on

surf

ace

(m

0

A B C D E F

A= 30% kenaf 6mm fiber/ soy composites injection molding

0.20

50

A B C D E F

Im

0 Fib

A= 30% kenaf 6mm fiber/ soy composites injection molding B= 33% Kenaf 6mm fiber/ soy compression molding C= 55% Kenaf 2mm fiber/ soy compression molding D= 56% Kenaf 6mm fiber/ soy compression molding E= 57% Kenaf 2 inch fiber /soy compression molding F= 54% Kenaf long fiber/ soy compression molding

Microfibrillated Cellulose (MFC)Microfibrillated Cellulose (MFC)Microfibrillated Cellulose (MFC)Microfibrillated Cellulose (MFC)Cellulose Nanowhiskers (CNW)Cellulose Nanowhiskers (CNW)

Di i t t dDisintegrated cellulose microfibrils - MFC

Crystalline region

Extracted cellulose

Crystalline region

Paracrystalline region

crystals - CNWs

The fringe-micelle modelA schematic of wood cell The fringe micelle model of cellulose microfibrils **

* Yamamoto, H., et al., Journal of Biomechanical Engineering, 124(2002), 432-440** Muhlethaler, Annu. Rev. Plant. Physiol., 1967, 18: 1-24

A schematic of wood cell wall ultrastructure *

Advantages of MFC and CNWAdvantages of MFC and CNW

Raw materials are abundant, cheap, and renewable

Biodegradable

High aspect ratio. Diameter from 3 to 20 nm; Length can be several  g p 3 ; ghundreds of nanometers.

Large relative surface area 

Less energy required in production compared with glass and carbon fibersgy q p p g

High modulus, high strength and low density

Density (g/cm3)

Tensile strength (GPa)

Young’s Modulus (GPa)

E glass fiber [1] 2.54 - 2.62 ~3.4 at 21 °C ~72.4 at 21 °C

Jute fiber [2] 1 3 1 45 0 39 0 77 13 26Jute fiber [2] 1.3 - 1.45 0.39 - 0.77 13 - 26

SiC whisker [3] 3.2 21.0 (max) 700 (max)

Cellulose nanowhisker [4]

1.5 ~10 ~150[4]

[1] Strong, Fundamentals of Composites Manufacturing: Materials, Methods and Applications, Society of Manufacturing Engineers, 1989[2] Mohanty, Misra, and Hinrichsen, Macromolecular Materials and Engineering, 2000, 276/277, 1-24[3] Kelly and Macmillan, Strong Solids, 3rd edition, Oxford University Press, New York, 1986 [4] Helbert, Cavaille, Dufresne, Polymer Composites, 1996, 17, 4, 604-611

Cellulose Micro+Nanowhiskers Cellulose Micro+Nanowhiskers Wheat StrawWheat StrawCellulose Micro+Nanowhiskers Cellulose Micro+Nanowhiskers -- Wheat StrawWheat Straw

Availability of wheat straw1.3-1.4 lb of straw per lb of wheat grain*58.7 million tons of wheat were produced in the US in 2004**627 1 million tons produced wordwide627.1 million tons produced wordwidePartial removal of straw does not hurt soil fertility

Straw as a low-cost feedstock for celluloseContains about 35-40 % celluloseIs being used for cellulosic ethanol production

MFC and CNW extraction strategy in our labMFC and CNW extraction strategy in our labPeracetic acid and alkali treatments High pressure homogenization (MFC)Acid hydrolysis, dialysis and ultrasonication (CNW)

* B.C. Saha and M.A. Cotta, Biotechnol. Prog, 2006,22, 449–453 ** Chen, et al, Appl. Biochem. Biotechnol, 2007, 142:276–290

Microfibrillated Cellulose (MFC) extracted from wheat strawextracted from wheat straw

2μm 100nm

The web-like structure of the MFC The width of the individual microfibrils is about 15 nm.

Cellulose Nanowhiskers (CNW)extracted from wheat strawextracted from wheat straw

500nm 200nm

The length and width of the extracted nanowhiskers are in the range of 100-200nm and 5-10nm respectively.

Aspect ratio: 20+, Modulus ~130 GPa, Strength ~10 GPap g

Polyvinyl Alcohol (PVOH) CompositesPolyvinyl Alcohol (PVOH) Composites

Advantages: PVOH is ater sol blePVOH is water solublePVOH is biodegradableEasy to process

DisadvantagesHygroscopic. Material properties affected by moisture content.Difficult to make bulk samples

Polyvinyl Alcohol (PVOH) CompositesPolyvinyl Alcohol (PVOH) Composites

i i Fil tiCNW suspension

S i ti

A simple solution - film casting method was used:

mixing Film-casting

PVOH water solution

Sonication

Ad tAdvantages: PVOH is water solublePVOH is biodegradableEasy to processy p

DisadvantagesHygroscopic. Material properties affected by moisture content.Difficult to make bulk samples

The thickness of the films was controlled to be approximately 100 micrometers. The films were conditioned in 20% relative humidity

Difficult to make bulk samples

Transparent Composite Films

WS-MFC / PVOH Films0% 1% 3% 5% 10%

WS-CNW / PVOH Films0% 1% 3% 5% 10%

f f % % C/ OAll films reinforced with cellulose nanowhiskers were transparent.

The 5wt% and 10wt% MFC/PVOH films were a little opaque.

WellWell­­Dispersed MFC in compositesDispersed MFC in composites

1 wt% MFC/PVOH 3 wt% MFC/PVOH

5 wt% MFC/PVOH 10 wt% MFC/PVOH

Excellent Dispersion of CNW in CompositesExcellent Dispersion of CNW in Composites

1 wt% CNW/PVOH 3 wt% CNW/PVOH

5 wt% CNW/PVOH 10 wt% CNW/PVOH

CNW/PVOH and MFC/PVOHCNW/PVOH and MFC/PVOHPlasma etched surfacesPlasma etched surfacesPlasma etched surfacesPlasma etched surfaces

With the polymer etched away by Oxygen Plasma, the fillers are exposed ...

10 t% MFC/PVOH 10 t% CNW/PVOH10 wt% MFC/PVOH 10 wt% CNW/PVOH

Notice the network structure formed by the MFC in the polymer matrix.

The white dots - CNWs.

Wheat Straw MFC/PVOH Composites­ Dynamic Mechanical AnalysisDynamic Mechanical Analysis

1 0 0 0 0

1 0 0 0 0 0

MPa

)

N e a t PV O H

1 w t% M F C /PV O H

3 w t% M F C /PV O H

5 w t% M F C /PV O H

1 0 w t% M F C /PV O H 0 .3

0 .4 N e a t PV O H

1 w t% M F C /PV O H

3 w t% M F C /PV O H

5 w t% M F C /PV O H

1 0 w t% M F C /PV O H

1 0 0

1 0 0 0

1 0 0 0 0

- 4 0 - 2 0 0 2 0 4 0 6 0 8 0 1 0 0

Stor

age

mod

ulus

(M

0

0 .1

0 .2

- 4 0 - 2 0 0 2 0 4 0 6 0 8 0 1 0 0

Tan The 

reinforcement effect became more significant above the 

Storage modulus Tan δ

T e m p e r a t u r e ( °C ) T e m p e r a t u r e ( °C )

Wheat Straw Wheat Straw CNWCNW/PVOH Composites/PVOH Composites

significant above the Tg of the polymer.

The improvement Wheat Straw Wheat Straw CNWCNW/PVOH Composites/PVOH Composites­­ Dynamic Mechanical AnalysisDynamic Mechanical Analysis

1 0 0 0 0 0

Pa)

N e a t P VO H1 w t% C N W /P VO H3 w t% C N W /P VO H

5 w t% C N W /P VO H 0 .3 0

0 .4 0 N e a t P VO H

1 w t% C N W /P VO H

3 w t% C N W /P VO H

5 w t% C N W /P VO H

1 0 w t% C N W /P VO H

of the storage modulus was much greater for the MFC filled PVOH than for 

1 0 0

1 0 0 0

1 0 0 0 0

Stor

age

mod

ulus

(MP 1 0 w t% C N W /P VO H

0 0 0

0 .1 0

0 .2 0

Tan

Del

ta

1 0 w t% C N W /P VO H filled PVOH than for the CNW filled PVOH films.   

1 0 0-4 0 -2 0 0 2 0 4 0 6 0 8 0 1 0 0

Te m pe r a ture (°C)

0 .0 0-4 0 -2 0 0 2 0 4 0 6 0 8 0 1 0 0

T e m p e r atu r e ( °C )

Storage modulus Tan δ

Comparison of the storage moduli at 20 Comparison of the storage moduli at 20 °°C + 85 C + 85 °°C C Storage modulus at 20 °C

6000

70008000

9000

us (M

Pa)

Storage modulus at 85 °C

400

500

600

s (M

Pa)

240% increase

0

10002000

30004000

5000

Stor

age

mod

ul

0

100

200

300

Stor

age

mod

ulus

Neat PVOHfilm

1wt% WS-MFC/PVOH

3wt% WS-MFC/PVOH

5wt% WS-MFC/PVOH

10wt% WS-MFC/PVOH

0Neat PVOH

film1wt% WS-MFC/PVOH

3wt% WS-MFC/PVOH

5wt% WS-MFC/PVOH

10wt% WS-MFC/PVOH

Storage modulus at 20 °C Storage modulus at 85 °C

Wheat Straw MFC / PVOH

Storage modulus at 20 C

50006000700080009000

ulus

(MP

a)

Storage modulus at 85 C

400

500

600

ulus

(MP

a)96% increase

010002000300040005000

Neat PVOH 1wt% WS- 3wt% WS- 5wt% WS- 10wt% WS-

Sto

rage

mod

u

0

100

200

300

Neat PVOH 1wt% WS- 3wt% WS- 5wt% WS- 10wt% WS-

Stor

age

mod

u

film CNW/PVOH CNW/PVOH CNW/PVOH CNW/PVOH film CNW/PVOH CNW/PVOH CNW/PVOH CNW/PVOH

Wheat Straw CNW / PVOH

BioBased Materials are a Value AddedBioBased Materials are a Value AddedProduct of a BIOREFINERY

Origin Processing Refining Intermediates Products

Feedstocks

Modifiedstarches

Citric acidItaconateL i

LubricantsCoatingsPolyols

Origin Processing Refining Intermediates Products

FeedstocksCornSoyWheat

Carbohydrate

Glucose

Fermentationfeedstocks

LysineLactic acidEthanolIsosorbide

PolyolsPlasticizersThermoplasticsUrethanesP lCanola

SugarFlaxSunflower

OilsFatty acids

IsosorbidePolyestersPlastic

intermediatesBioCompositesSunflower

GrassesBiomass

GlycerolBioComposites

BioFibersBioFibersMFC & CNW

Wheat Straw Ethanol Production ResidueWheat Straw Ethanol Production ResidueWheat Straw Ethanol Production ResidueWheat Straw Ethanol Production Residue

Cellulosic Ethanol from Wheat StrawCellulosic Ethanol from Wheat Straw Fuel from a waste instead of from foodAmmonia Fiber Expansion (AFEX) pretreatment at MBI and MSUAt 50-60% glucan conversion, what can we do with the rest of the cellulose in the residue ?

Possible applications of the fermentation residueBurnt to produce thermal energyBurnt to produce thermal energyPyrolysed to produce organic acids and other chemicalsProcessed into fertilizer or animal feed, etc.A possible cheap feedstock for MFC and CNWs ?

Ongoing effort of extracting MFC and CNW from the residue in our lab

Characterization of the residue (morphological and chemical)( p g )MFC and CNW extraction from the residueComposite preparation and characterization

Morphology ChangesMorphology Changes

Untreated wheat straw After Ethanol production

After being used for ethanol production, the cellular structure of the wheat straw is still largely preserved.

But the surface of the cell wall has become rougher and more heterogeneousBut the surface of the cell wall has become rougher and more heterogeneous.

MFC extracted from the residue

1μm 500nm

Surface Chemistry ChangesSurface Chemistry Changes

Raw Wheat Straw

1731

The peak at 1731 cm-1, which is characteristic of hemicellulose, disappeared.

A

AFEX+SSF Residue

1505

145814201593

More prominent peaks at 1420 cm-1, 1458 cm-1, 1505 cm-1 and 1593 cm-1, which are all characteristic peaks of

4000.0 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 650.0cm-1

lignin .

The theoretical values of O/C

O/C C1 % C2 % C3 %

Raw wheat 0.17 81.8 13.5 4.8

The theoretical values of O/C ratios for cellulose, hemicellulose, lignin and extractives are 0.83, 0.80, 0.33 and 0.04-0.12 respectively *.

straw

Residue 0.30 62.7 32.6 4.7 The untreated wheat straw is covered by extractives on the surface, while the AFEX+SSF residue has high concentration of lignin on the surface.

Opportunities…Opportunities…Plant Derived Fiber and Crop Derived PlasticsPlant Derived Fiber and Crop Derived Plastics

Biopolymer growth is expected to exceed~+25% per year over the next 3 yearsp y y

Global demand for biopolymers is forecast ~338,000 tons by 2012 with U.S. market ~$845 million

Structural composites (consumer) ~2-3 million tons by 2008 p ( ) yMarket demand for bio-based composites is being driven by:

Replace/Substitute Petroleum Based Composites Compete on a modulus, strength and impact basis p , g pRequire less energy to produce and processRenewability, Biodegradable, RecyclabilityMore competitive price structurep pGovernment / legislative tractionConsumer education & adoptionExpanded Market - Agricultural Industry p g y

Summary:Summary:yyCellulose Fibers from Plant have potential to replace Glass Fibers as Reinforcements in Polymer CompositesMicrofibrillated Cellulose (MFC) and Cellulose Nanowhiskers (CNW) from Wheat Straw have excellent mechanical propertiesmechanical properties

Stiffness, Strength Impact, Transparency

Challenges:Challenges:ggProperties of MFC and CNW after AFEX PretreatmentCost Effective Process for MCF and CNW Fibers Modification of Manufacturing Technology