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College of Agricultural SciencesCampus of Botucatu

BrazilCoordinatorCoordinator: Prof. Alcides Lopes Leão: Prof. Alcides Lopes Leão

EE--mail: mail: alcidesleao@fca.unesp.bralcidesleao@fca.unesp.br

55(14)381155(14)3811--7257 7257 -- BRAZILBRAZIL

POLYMER NANOCOMPOSITES WITH NANOWHISKERS ISOLATED FROM COIR

FIBRES

Alcides L. Leão & Sivoney F. SouzaUNESP - São Paulo State University, Botucatu, BrazilBibin Mathew Cherian – Mahatma Gandhi University,

India

.

unesp - Sao Paulo State University• Students: - Undergraduate: 34,425 (5,800/yr.)

- Graduate: 12,031 (2,000/yr)• Professors: 3,350 (more than 85% work full time in teaching,

research and extension services)• Staff: 6,984• Campuses: 23 in 21 cities• Laboratories: 1,900• Libraries: 30• Area Total: 62 million m2

• Area of Construction: 733,000 m2

• Budget 2008: USD 650 millions• Graduate Programs: 174 graduate courses at MSc. and PhD. levels

divided into 101 Master and 73 Doctorate courses• Undergraduate Programs: 168 undergraduate programs at

bachelor's level in nearly every knowledge areas and prepares students for 63 careers

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Processes Utilized in Composites at UNESP - Botucatu

• Extrusion (profiles and pellets) – macro, micro and nano • Injection molding• Thermoforming• BMC (partnership with private companies)• SMC (partnership with private companies)• RTM (partnership with private companies)• LFRT – Long Fiber Reinforced Thermoplastics (profiles

and railroad crossties)

Plastic Products and Environment

Plastic packaging materials is a big environment issue (world production is ca. 50 millton/ year and the market is ca.100 mill USDPackaging products constitutes ca 50% of total plastic usage

Rigid PackagingBuilding

Automotive

HpuseholdAppliances

Electrical

Wire & CableFibre

Others

Flexible Packaging

Importance of Natural Fibers

Cost effective

Renewable

Eco-friendly

Thermal insulators

Nonabrasive to processing equipment

Under utilized

Social responsible

Engineering Materials (Repetitive, Homogenous, Predictable)

Engineering Materials

Classics Non-classics

Wood GlassCeramics Metals Man-made Polymers

Classificação dos materiais de engenharia (MANO, 2000)

Biowaste

Collection

COMPOST

BiologicalDegradation

RENEWABLE RAW MATERIALS

Photosynthesis

HarvestingExtraction

10 to 20 tons dry mass /ha annualy

Strach Celluloses, Agrochemicals, hemicelluloses, biopolimer

Processing

INTERMEDIATESConversion

Materials Cycle

endothermic (capturing) 2,86 kJ/mol of glucose formed

PRODUCTSTextiles, composites, agrochemicals, energy

–

340 l ethanol/1ton straw

CO2

H2

O10 ton Biomass collecting 2,5 ton CO2

CLASSIFICATION OF NATURAL FIBRESNATURAL FIBRES

PLANT ANIMAL

BAST LEAF SEEDS FRUIT GRASS

Flax(Linum Usitatissimum)

Hemp(Cannabis Sativa)

Kenaf(Hibiscus Cannabinus)

Jute(Corchorus Capsularis)

Ramie(Boechmeria Nivea)

Isora(Helicteres Isora)

Ananas(Ananas Bracteatus)

Sisal(Agave Sisalana)

Abaca(Musa Textilis Nee)

Curaua(Ananas Erectifolius)

Cabuya(Furcraea Andina)

Palm

Opuntia(Opuntia Galapagos)

Paja(Carludovica Palmata)

Jukka(Yucca L)

African Palm

Chambira(Astrocaryum Chambira)

Cotton(Gossypium)

Coir(Cocos Nucifera)

Kapok(Ceiba Pentandra)

Soya(Glycine)

Poplar(Populus Tremula)

Calotropis(Calotropis Procera)

Coir(Cocos Nucifera)

Luffa(Luffa Aegyptiaca)

Bamboo(Bambusa Shreb.)

Totora(ScirpusCalifornicus)

WOOLS AND HAIR

SILK

Sheep(Ovis Aries)

Alpaca(Lama Pacos)

Camel(CamelusBactrianus)

Natural(Bombyx Mori L)

Spider Silk(Araneus Diadematus)

Goat(Genus Capra)

Horse(Equus Caballus)

Rabbit(OryctolagusCuniculus)

Vicuna(Lama Vicugna)

MINERAL

Asbestos

Glass

Mineral Wool

Basalt

Ceramic

Aluminium

Borate

Silicate

Carbon

WOOD

hardwood

softwood

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Natural Fibers in South America Brazil is the biggest producer and consumer

• Abaca – Ecuador• Fique – Colombia, Ecuador• Totora – Ecuador, Peru and

Bolivia• Flax – Argentina (?)• Embira – Brazil• Caroá – Brazil• Bamboo - Brazil• Phormium (imbira) - Brazil• Curaua – Brazil, Venezuela• Kurowa (curaua) - Guiana• Sugar cane bagasse – Brazil,

Cuba and Colombia,• Pineapple (Brazil)

• Sisal – Brazil, Cuba, Haiti México

• Buriti, Carnauba, Buriti, and Tucum – NE of Brazil (native palm trees

• Malva & Jute – Brazil• Coir – Brazil• Banana – Brazil• Hemp – Chile• Taboa (Typha) - Brazil• Piteira – Brazil and Ecuador• Tagua – Ecuador• Jarina – Brazil (Vegetable ivory)• Piaçava – Bahia, Brazil

Totora – Huros at Lake Titicaca

Arrangement of Fibrils, Microfibrils and Cellulose in the Cell Walls

Components Arrangement

Arrangement of Cellulose, Hemicellulose and Lignin in cell wall

Fibers CompostionItem Taboa Curaua Pineapple Banana Coir

ExtractivesHot Water (%)

8.5 5.5 6.0 10.6 6.4

Lignin Klason(%)

16.4 11.1 10.5 18.4 32.8

Holocellulose(%)

71.3 81.2 80.5 68.6 58.4

Cellulose(%)

35.0 70.4 73.4 64.2 44.2

Ashes(%)

3.8 2.2 3.0 2.4 2.4

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Advantages of Cellulose NanofibersRenewableBio-basedLow densityGood Surface appearanceReduced smoke emission.

Decreased permeability to gases, water and hydrocarbons.

Optical transparency

Nanofiber Scale

Nanocomposites

Bio based polymers and nano reinforcements

Improve the polymer properties:

Thermal stabilityMechanicalToughnessBarrierExpect that these materials

can be used in packaging, medical, automotive and textile

Why Bio-nanocomposites ?Nanocomposites from renewable rawmaterials for automotives Biodegradable films for packaging applications (barrier layers)Biodegradable packaging materialsMedical devices compatible with the human body

Bio-nanocomposites

Toyota

Bio based nanoreinforcements in biopolymers

Improve biopolymer properties:−

Thermal stability

−

Mechanical−

Toughness

−

Barrier

Expect that these materials can be used in packaging, medical, automotive and textile applications

Nanoparticles vs. Microparticles

Big variation of properties inherent to the natural products (climatic conditions, maturity, type of soil,...)

The basic idea to achieve further improved fiber and composite is to eliminate the macroscopic flaws by disintegrating the natural grown fibers, and separating the almost defect free highly crystalline fibrils

Increase of the specific area (~100 m2.g-1 vs. ~1 m2.g-1)The average inter-particles distance decreases as their size

decreasesParticle-particle interactions

Improved properties for low filler content without detrimental effect on impact resistance and plastic deformation

Reduction of gas diffusion (barrier effect)

Because these microfibrils contain only a small number of defects, their axial Young's modulus is close to the one derivedfrom theoretical chemistry and potentially stronger than steel and similar to Kevlar

100 nm 5 µm

Native cellulose consists of hierarchical structure (built up by smaller and mechanically stronger entities-

cellulose

fibrils)

Fibrils = crystalline + noncrystalline domains (surface + along the main axis)

Noncrystalline domains form weak spots along the fibrils

Cellulosic Nanoparticles

CELLULOSE FIBERS STRUCTURAL ENGINEERING

Source of Cellulose Fibers

Coir

Cellulose Microfibrills and Whiskers

• Wood fiber, diam 20-30 μm, length 2-5 mm• Microfibrills, diam <30 nm, length > μm• Whiskers, diam 3-10 nm, length < 300 nm• Mechanical properties increases when size

decreases• Fiber 40 GPa whisker 160 GPa

•

The isolation of MF and CNW from wood resources•

Whiskers are the crystalline parts of cellulose

Cellulose Nano-entity Research Value Chain: Economics and Environment

Cellulose Whiskers

Cellulose Nanofibers Isolation Process

Cellulose Nano Whiskers from MCC

Commercial available microcrystalline celluose (MCC)MCC is aggregated cellulose crystallites which needs

to be swelled or isolated before processing to nanocomposites

High mechanical properties, theoretical modulus calculated to ~167GPa (Tashiro.K., Koayashi. M, Polymer (32), 1991)

High Shear Refining of Cellulose (Nano)-fiber Production

Isolation of Cellulose Nano Whiskers

Acid hydrolysis with HCL or H

20 µm 200 nm

MCC 10-15 µm Cellulose Whiskers

Nanofiber Isolation by Heat Treatment

Raw Plant Fiber

Steam explosionBleaching

Acid HydrolysisCrushing

Nanofibrils

Mechanical agitation Acid Treatment

Isolation of Nanocellulose From NF

Pressure Drop

Nanostructure Characterization

Microscopy

Scanning Electron Microscopy(SEM-5 nm, ESEM -1 nm-especially

for biomaterials)

Transmission Electron Microscopy(TEM-0.2 nm)

Atomic Force Microscopy (AFM-1nmx,y , 0.1nmz)

Biobased nanoreinforcements and nanocomposites (≤3nm)

Raw Coir Fiber Steam Exploded Coir Fiber

Bleached Coir Fiber

ESEM Micrograph of Acid Treated Coir Nanofibril Suspension

Transmission Electron Micrographs of Cellulose Nanofibrils of Coir

•Well defined nanofibrils•The diameter of the whiskers are ~ 5nm•Narrow size distribution, reduced agglomerates

Atomic Force Microscograph of Coir Whiskers

Well defined nano whiskersThe diameter of the whiskers are ~ 15nmNarrow size distribution, no big agglomerates

HCL prepared whiskers better thermal stability compared to H2

SO4

K. Oksman, P. Syreand

D. Bondeson, Patent appl. NO20065147 and US 10/560190 D. Bondeson, P. Syre, K. Oksman, Journal of Biomaterials and Bioenergyin

press

Thermal Stability of the Whiskers

IsolationFind suitable chemicals

Freeze dryingRe-aggregates

Re-dispersionDifficult in other than water

Preparation of CNW

Processing of Nanocomposites

Preferred processing medium = water because of high stability of aqueous polysaccharide nanocrystal

dispersions.

Matrix = hydrosoluble polymers

Water evaporation Nanocomposite film

Nanocomposite Process: Solution Casting

Advantages: + low temperature+ only a few grams+ uniform thickness

Drawbacks: -

use of solvent-

lab scale

- time consuming-

difficult if non water soluble polymer are used

Processing of Nanocomposites

Alternative = use of an aqueous dispersed polymer (latex)

Water evaporation (T>Tg) Particle coalescence Nanocomposite film

Alternative = non aqueous systems

Dispersion of polysaccharide nanocrystals in an organic medium

Coating of nanoparticlessurface with a surfactant

Chemical modificationof nanoparticles surface

High specific area : high amount of surfactant

(x4 for tunicin

whiskers)

Involves reactive OH groups from the surface

Processing of Nanocomposites

Processing of Nanocomposites

Alternative = non aqueous systems

Dispersion of polysaccharide nanocrystals in an organic medium

Use of anadequate solvent

Solvent exchange procedure

Dispersion of cellulose whiskers in Dimethylformamide(DMF), dimethyl

sulfoxide(DMSO) or N-methyl surface modification

Water Acetone Toluene

Alternative = dry nanoparticles

Processing of Nanocomposites

Aggregation of polysaccharide nanocrystals

Filtration of the suspension film + immersion in a polymer solution

Melt extrusion

Bio-nanocomposite Solid Phase Processing

Nanocomposite Process: Melt Compounding

Mixing the melt polymer and nano

whiskers in a twin screw

extruderPossible to scale upPossible to compression mold

or injection mold samplesHigh temperature processLarge amount of materials is

needed

Challenges in Melt Compounding

5 µm

100 nm

Feeding of nano whiskers into the extruderLiquid feeding – Suitable feeding liquid – Concetration– Remove the high amount of liquidDry feeding– Avoid re-aggregation druring drying– Low bulk density material– Get uniform dispersion of nano whiskers – Processing parameters; Surface modifications– Compatibilizers; Processing aids

Thermoforming

Injection

Moulding

Electrospinning

Dynamic Mechanical Thermal Properties

The dynamic modulus was improved in elastic and plastic areas and the tan delta peak is moved towards higher temperature, 117°C 148°C better thermal stability

Mechanical Properties

Dramatic improvement of modulus and strengthElongation to break and toughness were decreased

D. Bondeson, P. Syreand

K. Oksman, Journal of Biomaterials and Bioenergy, in press.

Cellulose and Polyurethane Nanocomposite

TEM image of PU/CW XRD patterns of cellulose and PU/C3

Process

Magnetic Field

I. Kvien

and K. Oksman, Orientation of Cellulose Nanowhiskers in Polyvinyl Alcohol (PVA), Applied Physics A, 87, (2007), 641-643.

CNW TEM

PVA PVA-CNW

“The most environmentally friendly thing that you can do for

a car that burns gasoline is to make lighter bodies”

“They (automobiles) will be

lighter and much of them will be

built of plastics developed from

farm products”.Henry Ford, from an article written by James Schweinehart published in The

Detroit News of July, 30rd, 1942.

Automobile Applications

TOYOTA BODY

Composite spare-tyre carrier for Mercedes-Benz A-Class minicar made from banana fibre reinforced composites

Natural Fbres & High Impact?

(Sonntag & Barthel, 2002)

Plant Fibre Utilisation per vehicle (Brazil – 13 kg)

• Front door liners: 1.2-1.8 kg• Rear door liners: 0.8-1.5 kg• Boot liners: 1.5-2.5 kg• Parcel Shelves: <2 kg• Seat Backs: 1.6-2.0 kg• Sunroof Interior Shields:<0.4 kg• Headrests: ~2.5 kg

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Auto Production by Country

Production (in

Millions) - 2009

Japan 9.62USA 7.22Germany 4.82S. Korea 2.91Brazil 3.10France 2.23

Fox Models: parts made of curauá

FOX Moulded

Headliner

Carrier: 50/50 Curauá

Fiber

+ Polymeric

Resin

FOX Trunk

Lid

FOX Sliding

RoofDeveloped in partnership with UNESP

Artificial Hip Joints

Artificial Ligaments

Biomedical Application

Features of the Nanocellulose PackThree dimensional gauze

With the intensity of a high gel phase, the three dimensional gauze has a close-Knit structure 500 times

that of non-woven fabrics and 10 times its moisture.

Removes dirt through high density structure It is highly absorbent, and with its high density

structure, it effectively stays on and revitalizes the skin, It an also be used for medical purposes.

Deep moisturizing As a deep moisturizing pack, it contains vitamin,

collagen, aloe, chamomile and rosemary, and shows visible results in a short time.

Skin safety It is developed by fermented fruit juice and its safety

has already been verified.

Cosmetic Application (Nanocellulose Pack)

Sanitary Napkin Nanocellulose Coated Sanitary Pad Utilized for the Repeated

Absorption of Menstrual Fluid

Biomedical Application Continued…….

Plate Type Dialyser

Hollow Fibre Dialyser

Surgical Equipments

Disposable Plastic Blood Bag

Biomedical Application Continued…….

Biomedical Application Continued…….

Artificial

Ligaments

Artificial Hip Joints

Biomedical Application Continued…….

Dental Bridges

Biomedical Application Continued…….

Metal-free orthodontic retainers which

strengthens the tooth after Root Canal treatment

Artificial Heart Valve

Biomedical Application Continued…….

Heart Valve Top View

Nanobial Cellulose Membrane

Conformability to the various body contours, maintains a moist environment, and significantly reduces pain

Wound covering for skin problems such as burns and chronic ulcers

Biomedical Application

Packaging: Cellulosic nanofibers perform outstandingly as a oxygen and water barrier in the polymer matrices.Application: food and pharmaceutical packagingRadio Frequency ID Tags: ID tags printed on cellulosic paper possess impressive computer power and RF capability, and are inexpensiveApplication: track commercial products remotely, detect counterfeit drugs and protect product integrity

Biomedical Application

Cellulosic nanofibers have unique mechanical, optical, electrical and chemical properties that can be utilized in a variety of diverse applications.

Successful and positive results have been achieved through the efforts of many dedicative research and studies.

However, the scaling-up and the long-term durability of the nanocomposites remain as a question.

Conclusions

The Future

The future of the materials based on FPC composites depend on many factors, such as:

1. Identification of new products;2. Quality of the products;3. Consumers perception;4. Performance of the products; and5. Identification with innovation

Life is pretty simple:You do some stuff. Most Fails. Some

Works. You do more what works. If it works big, others quickly

copy it.Then you do something else. The trick is the doing

something else

Leonardo da Vinci

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ACKNOWLEDGMENTS• CNPq – National Council for Research – Brazil• FAPESP – São Paulo Research Support Agency