Sustainable composites

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
9
Youngs moduli of fibres
10
Strengths of fibres
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) gt sliver
• spinning (twisting binds fibres) gt 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/Abou
t-Henry-Ford-s-Car.html
21
JuteCorchorus capsularis. L. - white juteC.
olitorius L. - Tossa jute.

• The Golden Fibrehttp//www.bdcom-online.com/shath
  i/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/nettl
  e.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/s 9 GPa/91 MPa
• 23 v/o nettle/phenolic E/s 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

• Youngs modulus
• Ec ??d?l?oVfEf VmEm
• Strength
• s ?Vfsf Vmsm
• ? fibre area correction factor
• ?d fibre diameter distribution factor

26
? fibre area correction factor?d fibre
diameter distribution factor

• ? corrects for true area or irregular CSAwhen
  apparent fibre diameter is measured
• ?d 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
  fibresthe 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
Dissanayake LCIA matrix
32
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

33
Nilminis interim analysis

• Environmental Impact for Flax fibre

See also http//www.netcomposites.com/downloads/03
Thurs_Summerscales.pdf - slide 15
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