Weronika Pawelec

Mahdi Pahlevan

Michal Wagner

BiocompositesBiocomposites

Polymeric Materials Course

Outline

• Background

• Scope of the research

• Examples

• Applications

• Recycling

• Conclusions

Background/Therms

Materials capable of being decomposed by the action of living organisms. Left to itself, it will be

decomposed by natural processes.

Materials consist of two or more physically distinct phases, which when combined together result in

material with different properties from those of the individual components [1]

Biodegradable composite materials consist of biodegradable polymers as the matrix material and

biodegradable fillers, usually biofibres (e.g.lignocellulose fibres). Since both components are

biodegradable, the composite as the integral part is also expected to be biodegradable [5]

Biodegradable

Composites

Biocomposites

1. Reinforcement/Filler• Natural fibres (cotton, flax, hemp)

• Fibres from recycled wood or waste paper (leaf, pineapple)

• By-products from food crops (Seed)

2. Matrices• Polymers derived from renewable resources

(vegetable oils or starches)

• Synthetic fossil-derives polymers • Virgin or recycled thermoplastics

(PE,PP,PS,PVC)

• Virgn thermosets (unsaturated polyesters, phenol formaldehyde, isocyanates, epoxies)

Biocomposite reinforcement

=

+ matrice

• Hydrophobic (petrochemical)• Hydrophilic (cellulose etc.)

Function of Elements

Function of reinforcement

Provide strength and stiffness

Act as reinforcement in fibre-reinforcement composites

Properties of the composite are controlled by properties of the fillers

Function of matrix

Holds the fibers together

Transmit externally applied loads to the reinforcement

Protect the reinforcement from environmental and mechanical damage

Natural Fibres

Natural fibers

Vegetable Animal Mineral

Seed hair Bast fibers Hard fibres Wool/hair Silk Asbestos

CottonKapokAkon

FlaxHempJute

Ramie

AgaveBananaBromeliaCocos

SheepCamel

Rabbits hair

Mulberry silkCoarse silk

Biodegradable polymers

Progress in Polymer Science 34 (2009) 125–155

Requirements for high-quality biocomposites

Good mechanical properties (for both the matrix and reinforceing fibre)

Good fibre - matrix adhesion

Low viscosity of polymer matrix at the processing temperature

Develop maximum strenght of material Toughness Compatibility• Hydropfilic fibres (cellulosics)• Hydrophilic polymer matrix (polyesters, ethers) Weak bonds lead to failure, fibre pull-out

Fibre architecture

Geometry

Orientation

Packaging arrangement

Volume fraction

Polymer performance

Enhancement of composite properties

-surface modification

-coating

-derivatization

Careful selection

of polymer matrix and

fillers

Careful selection

of polymer matrix and

fillers

Methods promoting adhesion

Methods promoting adhesion

- hydrophilic fibres + hydrophilic matrix

Factors limiting use of natural polymers and bio-fibres

Low compatibility with

hydrophobic polymer matrices

Thermal sensitivity

Flammability

Cost of

accreditation

Technical,

Commercial,

consumer bariers

limited availabilityirregular fiber

shape

finite fiber length

fiber variability

poor adhesion

Drawbacks

Barriers to uptake

Reasons for commercial interest

• Biodegradable• Renovable row material base• Reduced fossil fuel and resource consumption• Lower greenhouse gas emission• Carbon dioxide reduction in nature• Lower overall emisions and environmental impacts

• Easy designed and tailored to meet different requirements

• Light weight, Low density• High mechanical properties• Strong, Durable• Corrosion resistance• Good insulation and UV capabilities• Flexible• High performance, high value products

• Low cost• Possibility for repalacement of fiberglass, wood and

plastic panels

Properties

Environment

Market

- alternative for traditional materials

Why composites needs to be biodegradable?

Environmental and health concerns

Third world development

Biomimetics

• Growing concern for clean environment• Greater social concern• Sustainable• Waste disposal, recycling• Reduced energy consumption• Legislations

•New materials, new methods

of manufacture• Need for improvement of traditional technologies• Depletion of petrochemical resources• Facing new desires• Responsibility for products

• Plants as natural structures

Trends/Research topics

Mimicking structures of living materials Fillers and fibres for reinforcement and

osteoconductivity Processing of cellular composites,

supercritical gas foaming Biocompatibility (in vitro and in vivo

evaluation of polymer composites) Scaffolds for bone tissue engineering

Aims/future

Obtain a biodegradable, environmentally friendly product

Broadening of biocomposites market for different industrial applications

• Development and production of engineering composite materials made entirely from renewable resources

Optimum properties to meet end use requirements

• Improvement in the mechanical performance of existing biocomposites• Maximise the proportion of renowable resources used while retaining desired material properties• Polymer formulations must be further researched and modified

Development in processing technology

• Optimazing processes parameters.

Intensive cooperation among industries, research institutes and governments

Biodegradable Materials

Density Glass transition temperature

(Tg) Melt temperature (Tm) Water absorption Degradation time Mechanical properties

Important factors for biodegradable materials

Manufacture of biocomposites

1. Hand lay-up2. Filament winding3. Pultrusion 4. Extrusion5. Press moulding6. Injection moulding7. Rotational moulding8. Compression moulding9. Resin transfer moulding10. Sheet moulding compounding

Typical Examples

(a) (b) (c)

(d) (e) (f)

Starch Plastics

• Natural hydrophilic polymer• Consist of linear amylose and branched amylo-pectin• Rapid degradation is an advantage vs synthesized

polymers• Can be made thermoplastic• Products with different properties can be prepared with

change condition of polymerization• Its sensivity to humidity is disadvantage for many

applications• Mainly used in soluble compostable foams

Starch Plastics

Cellulose acetate

Modified polysaccharide synthesized by the reaction of acetic anhydride with cotton linters or wood pulp

Also from recycled paper and sugar cane

Important factor for CA is Degree of Substitution (DS)

CA is a poor substrate for microbial attacks

CA must be plasticized if they are to be used in thermoplastic applications

CA films have a tensile strength comparable to polystyrene, so CA is suitable for injection moulding

CA is used to produce clear adhesive tape, tool handles, eyeglass frames, textiles and related materials

Soy Plastic

Soybeans typically consist of 20% oil and up to 55% Protein

Discrete groups of protein (Polypeptides) contains 38% non-polar, non-active amino acid residue and 58% polar and reactive

Soy protein has unusual adhesive properties

Dried soy plastics display high modulus

Blending with polyphosphate filler greatly reduced its water sensitivity

Aliphatic Polyesters

Can be classified in two groups regarding the mode of bonding of constituent monomers

• Polyhydroxyalkanoates – polymers of hydroxy acid

• poly(alkylene dicarboxylate)s – synthesized by polycondensation reaction of diols and dicarboxylic acids

• hydroxy acids are classified into α-, β- and ω-hydroxy acids in respect of bonding position of the OH group

Aliphatic Polyesters

Poly(α-hydroxy acid)– Poly(glycolic acid) – PGA

– Poly(lactic acid) – PLA

Poly(β-hydroxyalkanoate)s – PHAs– Poly(β -hydroxybutyrate) (PHB) (commercial name Biopol)

– Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)

Poly(ω-hydroxyalkanoate)– Poly(ε-caprolactone) – PCL

• Poly(alkylene dicarboxylate)– Poly(butylene succinate – PBS

– Poly(butylene succinate-co-butyleneadipate) – PBSA

– Poly(ethylene succinate) – PES

Aliphatic Polyesters

Applications (1)

North American market demand of natural fibers

Applications (2)

• Building industry

• Automotive industry

• Medicine

Building industry (1)

Particle boards based on sunflower stalks

It is possible to produce particleboards from the chips of sunflower stalks alone by using urea-formaldehyde adhesives.

Sufficient mechanical properties for this application however increase in the sunflower particles decreases mechanical strength.

Journal of COMPOSITE MATERIALS, Vol. 39, No. 5/2005

Building industry (2)Soy oil/cellulose fibers composites for roofs

Composite Structures 74 (2006) 379–388

Automotive industry

Macromol. Mater. Eng. 2006, 291, 449–457

MedicineTi/polymer biocomposite implant

Journal of Materials Processing Technology 197 (2008) 428–433

Recycling

Biodegradation:

UV degradation weight loss of different starch biocomposites (5 % glycerine)

Samples of sisal starch composites at fiber content of 5% w=w and at glycerine contents of 12.5% w=w at 2, 5, 7 and 9 days of exposition in agar medium.

The recycling concept:

The big challenge for the future!!!

International Journal of Polymeric Materials, 55:1115–1132, 2006

Conclusions:

• More composites materials are considered as biocomposites

• Biocomposites market is still improved and broaded

• Further research still need to be continued

• Effords involved in research and production is a big step in the right direction-eco direction thus biocomposites still will get much attention in the future

References:• [1] J.Sci Food Agric 86, 1781-1789, 2006• [2] Macromol. Mater. Eng. 276/277, 1-24, 2000• [3] Progress in Polymer Science 34, 125–155, 2009• [4] Polymer Degradation and Stability 88, 138-145, 2005• [5] Carbohydrate Polymers 56,111-112, 2004• [6] Caroline Baille, Green composites, Polymer composites and the environment• [7] Biodegradable composites based on lignocellulosic fibers. An overview - Kestur G. Satyanarayana et al –Composites 2008• [8] Mechanical properties of poly (butylene succinate) (PBS) biocomposites reinforced with surface modified jute fibre”, Lifang Liu et al – 2008• [9] Composite Interfaces, Vol. 8, No. 5, pp. 313–343, 2001• [10] Journal of Composite Materials, Vol. 39, No. 5, 2005• [11] Composite Structures 74, 379–388, 2006• [12] Macromol. Mater. Eng. 291, 449–457, 2006• [13] Journal of Materials Processing Technology 197, 428–433, 2008• [14] International Journal of Polymeric Materials, 55, 1115–1132, 2006

Thank you for your attention!!!!