Kristiina Oksman and Aji Mathew Department of Engineering Design and Materials NTNU Biopolymer Based Nanocomposites Biocomposite group Outline • Introduction to Nanocomposites Definition of nanocomposites Processing Applications • Bio Nanocomposites Why? Raw materials PLA nanocomposites Problems Conclusion PLA/CLAY Definition of nanocomposite: 1D, Layered silicates 2D, Carbon nanotubes Cellulose whiskers 3D, Gold particles, Inorganic oxides Composite materials where at least one dimension of the reinforcement is in the range of 1-100 nm
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Biopolymer Based Nanocomposites - Norges forskningsråd KOksman.pdf · Kristiina Oksman and Aji Mathew Department of Engineering Design and Materials NTNU Biopolymer Based Nanocomposites
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Kristiina Oksmanand
Aji Mathew
Department of Engineering Design and MaterialsNTNU
Biopolymer Based Nanocomposites
Biocomposite group
Outline
• Introduction to Nanocomposites� Definition of nanocomposites� Processing� Applications
• Bio Nanocomposites� Why?� Raw materials� PLA nanocomposites� Problems� Conclusion
Composite materials where at least one dimension of the reinforcement is in the range of 1-100 nm
Nanocomposites applications on the market
• Automotive exterior claddings
• Barrier layers in beer bottles
• Pipe and wire coatings
Süd-Chemie
GM side step
Amcor
Processing methods
• In-situ polymerisation� Clay based composites with nylon (Toyota) � Used for preparation of thermoset polymers and elastomer clay
nanocomposites
• Solution casting� Most common used processing method� Many different materials are used� Thin films
• Melt blending� New method� Can be implemented in industry� Clay based nanocomposites with PS, nylon, PP, PLA
Bio-Nanocomposites, Why?
• Improve the following biopolymer properties:� Mechanical� Thermal stability� Toughness� Barrier� Biodegradability
• Use renewable raw materials
Nano reinforcements
• Clay (natural and synthetic) are used to enhance: barrier and mechanical properties, fire retardancy and thermal stability(6-44 $/kg)
• Cellulose whiskers can be used: mechanicalproperties, barrier properties, thermalstability, biodegradability(14 $/kg + treatments)
The matrix polymers for commercial applications are: PP, PET and Nylon
Cellulose whiskers and fibrils
Wood fibre: length 2-4 mm, width 20-40 µm
Microfibril: infinite length and width about 10-20 nm
Length of crystalline region 300-600 nm
Wood fiber
3.5 mm
20 µm
10 nm
Other sources: different plants (flax, hemp etc.), root crops, sea animals…
Photo M. Sain, University of Toronto
Biopolymer matrices
• Polylactic Acid (PLA) is a polyester and originates from renewable agricultural raw materials (corn). It is completely biodegradable in natural systems when water and micro-organisms are present, Cargill-Dow, NatureWorks®
• Starch based polymers, are biodegradable polymers based on starch usually from corn, Evercorn™,USA, Novamont, MaterBi, Italy
• Cellulose esters, orginates from cellulose. Cellulose Acetate Butyrate (CAB) and Cellulose Acetate Propionate (CAP), Cellulose Acetate (CA), Eastman Chemicals Company, USA
• Bacteria produced polyester, Polyhydroxy Alkanoate (PHA), obtained from renewable resources, is waterproof and fullybiodegradable, Metabolix, USA
Ongoing activities: PLA nanocomposites
Separation of cellulose whiskers and clay• Chemical treatments and sonification
Solution casting of thin films• Blending of polymer solution and
separated nano whiskers/particles• Casting and drying at RT
Melt blending• Melt extrusion of polymer and nano
whiskers/particles• Compression molding of samples
Ongoing studies on nanocomposites
• Nanostructurecharacterisation� TEM, AFM, SEM� X-ray