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Sustainable composites

Sustainable composites. John Summerscales. Sustainability. Brundtland Commission Report (1987) The World Commission on Environment and Development suggested the following definition of Sustainable Development:

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Sustainable composites

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  1. Sustainable composites John Summerscales

  2. Sustainability Brundtland Commission Report (1987) The World Commission on Environment and Development suggested the following definition of Sustainable Development: "Meeting the needs of the present without compromising the ability of future generations to meet their own needs."

  3. Sustainability • Bruntland emphasised the need to balance: • economics • environment • social • governance • Now generally reduced to “Triple E” • Economy • Ecology • Equity

  4. Life Cycle Assessment • Four different phases [Brady]: • Goal and scope definition: in the context of the intended application. • Inventory analysis:collect data, quantifies relevant inputs and outputs. • Impact assessment:translates inventory analysis into impactsevaluating significance of the respective impacts. • Interpretation:conclusions and recommendations for decision makers

  5. Adisa Azapagic • Environmental impact classification factors: • Non-Renewable/Abiotic Resource Depletion (NRADP) • Global Warming Potential (GWP) • Ozone Depletion Potential (ODP) • Acidification Potential (AP) • Eutrophication Potential (EP) • Photochemical Oxidants Creation Potential (POCP) • Human Toxicity Potential (HTP) • Aquatic Toxicity Potential (ATP)

  6. Sustainable composites This lecture describes materials from natural sources, without prejudice to the results of any future Quantitative Life Cycle Analysis (QLCA)which may (or may not) make the case for these materials being more environmentally-friendlythan equivalent systems manufactured from man-made fibres and synthetic resins.

  7. Typical fibre properties • The data on the next three slides is from: • NL Hancox, Fibre Composite Hybrid Materials, Elsevier Applied Science, Barking, 1981. • TJ Reinhart, Engineered Materials Handbook 1: Composites, ASM International, 1987. • Chand et al, Journal of Materials Science,1988, 23(2), 381-387. • where a range is given in the references,the arithmetic mean is shown in the graph

  8. Density of fibres Bast (plant stem)Leaf Seed Animal Synthetic 1500 kg/m3 Carbon Aramid Glass Silk Coir Cotton Sisal Pineapple Jute Hemp Flax

  9. Young’s moduli of fibres Bast (plant stem) Leaf Seed Animal Synthetic 100 GPa Carbon Aramid Glass Silk Coir Cotton Sisal Pineapple Jute Hemp Flax

  10. Strengths of fibres 3 GPa Bast (plant stem) Leaf Seed Animal Synthetic 2 GPa Carbon Aramid Glass Silk Coir . Cotton Sisal Pineapple Jute Hemp Flax 1 GPa

  11. Fibre specific moduli and strengths • Specific value is (modulus or strength)/density • i.e. (MN/m2)/(kg/m3) = MN.m/kg

  12. Flax Flax and linseed are cultivars grown for fibre or seedrespectively Flax Field, Providence by Hazel Barker From http://www.art.com/asp/sp-asp/_/pd--10125356/Flax_Field_Providence.htm

  13. Flax/Linseed (Linum usitatissimum L.) • Mike Felstead: Flax and linseed fibres as reinforcement for epoxy composites,BEng Composites, June 1995.

  14. Flax: growth stages • 12 distinct growth stages in the flax plant: • Growth stages 1 & 2 • cotyledon (seed leaf) to growing point emerged • Growth stages 3 & 4 • 1st pair of true leaves unfolded to third pair of true leaves unfolded • Growth stage 5 • stem extension • Growth stages 6, 7, & 8 • buds visible to full flower • Growth stages 9, 10 & 11 • late flower to brown capsule • Growth stage 12 • seed ripe

  15. FLAX: growth stages Life cycle of the flax plant consists of • a 45-60 day vegetative period, • a 15-25 day flowering period, and • a maturation period of 30 to 40 days J A Turner “Linseed Law” BASF (UK) Limited, 1987 via http://www.flaxcouncil.ca/images

  16. Flax: from plant to fabric • harvest (combining or pulling) • retting (dew-, wet-, stand- or enzyme-retting) • enzymes (e.g. pectinase digests pectin binder) • decortication (scutching) • Hammer mill • Fluted rollers • Willower • cleaning (removal of shive) • carding (brushing/combing aligns fibres) > sliver • spinning (twisting binds fibres) > yarn/filament • weaving, braiding, knitting, etc

  17. Hemp (Cannabis sativa L.) • annual plant native to central Asia and grown in China over 4500 years ago. • probably reached central Europe in the Iron Age (circa 400 BC) • evidence of growth in the UKby the Anglo-Saxons (800-1000 AD). • does not require fertiliser, herbicides or pesticides to grow well • in suitable warm conditions,it can grow to 4 metres in just 12 weeks.

  18. Hemp (Cannabis sativa L.) Disadvantage? • some strains of this plant are ...psychotropic • those good for the above are not best for fibre • ... but good fibre plant can be used to disguise plants grown for drugs • new strains of fibre plant with distinctive leaf colours are under development

  19. Henry Ford car 1941 hemp and flax fibres used in resin matrix composites for body of Henry Ford car able to withstand ten-times the impact on an equivalent metal panel Video

  20. Henry Ford tries out his first carmade from plant based materials"the axe bounced, and there was no dent" Image from http://www.chanvre-info.ch/info/en/About-Henry-Ford-s-Car.html

  21. JuteCorchorus capsularis. L. - white juteC. olitorius L. - Tossa jute. • The Golden Fibrehttp://www.bdcom-online.com/shathi/jute.htm • Biotechnology in jute fibre processinghttp://www.epbbd.com/month23/Background.htm

  22. Kenaf (Hibiscus cannabinus L.) • fibre plant native to east-central Africa. • common wild plant of tropical and subtropical Africa and Asia • grown for several thousand years for food and fibre • unique combination of long bast and short core fibres • two crops/year in Malaysia

  23. Nettle (Urtica dioica) • Nettles yield ~ 8-10 tonnes fibre/acre http://jacksonsrow.topcities.com/tikun_olam/nettle.html • far stronger than cotton but is finer than other bast fibres such as hemp • much more environmentally friendly fibre crop than cotton, which requires more irrigation and agrochemical input

  24. Nettle • 24 v/o nettle/epoxy E/σ’ = 9 GPa/91 MPa • 23 v/o nettle/phenolic E/σ’ = 5 GPa/13MPa • 21 v/o flax/epoxy “strength and stiffness are more than twice as high” Ann-Jeanette Merilä, Stinging nettle fibres as reinforcement in thermoset matrices, MSc Engineering/Materials Technology, Luleå University of Technologyhttp://epubl.luth.se/1402-1617/2000/235/index-en.html

  25. Rules-of-mixture for NFRP • Young’s modulus: • Ec = κηdηlηoVfEf + VmEm • Strength: • σ’ = κVfσf’ + Vmσm* • κ = fibre area correction factor • ηd = fibre diameter distribution factor

  26. κ = fibre area correction factorηd = fibre diameter distribution factor • κ corrects for true area or irregular CSAwhen apparent fibre diameter is measured • ηd = fibre diameter distribution factor • data below from Christophe Baley at USB

  27. Are natural fibres good? • “natural fibre production requires less than 10 percent of the energy used for production of PP fibres (around 90 GJ/tonne)”, but ..... JEG van Dam and HL Bos, Consultation on natural fibres:the environmental impact of hard fibres and jute in non-textile industrial applications ESC-Fibres Consultation no 04/4, Rome, 15-16 December 2004.

  28. Are natural fibres good? ..... that data is total energy input for jute fibre cultivation (excluding field labour, retting and decortication)when grown by numerous small farmers utilising labour and animal power with limited agrochemicals and machinery

  29. Are natural fibres good? Environmental issues • Depletion of soil nutrients/fertiliser • Competition from weeds/herbicides • Competition from animals/pesticides Economic issues • Agricultural subsidies • Dependence on weather • Market price vs other producers

  30. Are natural fibres good? Data from TexFlax project thesis for flax: • ploughed • seed sown • pesticide applied (twice) • N applied • P/K applied • herbicide applied (twice) • harvested How much fuel went through the tractor, and how much energy was in the sprayed materials?

  31. The future ? • Extracting fibre without damage • Effective coupling agents • cellulose chemistry instead of silanes • Environmental durability • barriers to prevent moisture absorption • sterilise fibres to prevent biodeterioration • Quantitative Life Cycle Assessment (QLCA) • Other issues ? • BS8905 adds “Land Use” as 9th EICF • growing food vs fuel, feedstock, fibre

  32. Nilmini’s interim analysis Environmental Impact for Flax fibre: See also http://www.netcomposites.com/downloads/03Thurs_Summerscales.pdf - slide 15

  33. Environmental burdens: flax • embodied energies for flax (no-till agriculture): • 54 GJ/tonne for sliver (55 GJ/tonne for glass mat) • 80 GJ/tonne for yarn (32 GJ/tonne for continuous glass) minimum < middle < maximum • no till <conservation agriculture<mouldboard plough • organic fertiliser <agro-chemicals • biological control of pests<pesticides • water- <dew- <bio-retting • sliver <spun yarn

  34. Bio-based resin systems Thermoplastics • CPLA (polylactide aliphatic copolymer) • PCL (polycaprolactone) • PGA (polyglycolicacid) • PHA (polyhydroxyalkanoate) • PHB (poly-beta-hydroxybutyrate) • PHBV (polyhydroxybutyrate-valerate) • PLA (polylactide) • DuPontTM Sorona®

  35. Bio-based resin systems Thermosets • Acrylised epoxidised soybean oil (Aropol Envirez 5000, UCB Ebecryl) • Cashew Nut Shell Liquid (CNSL) • Epoxidised linseed oil .. and .. polycarboxylic acid anhydrides • Partially norbornylized linseed oil (Dilulin®) • Rapeseed-oil derived resins

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