Plastics and Composites

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Plastics and Composites
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Plastics

• Derived from petroleum and natural gas, types of
  FOSSIL FEULS.

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Plastics

• Monomers are extracted to synthesize plastic.
• Monomers are linked into chains to form polymers.

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Plastic

• Definition a material made up of polymers to
  which various substances are added to obtain
  desirable qualities.

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2 categories of plastics

• Thermoplastics becomes soft enough when heated
  to be moulded and remoulded but hardens enough
  when cool to hold its shape.
• 3/4ths of plastics
• Recyclable

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2 categories of plastics

• Thermosetting plastic maintains its shape even
  when heated.
• Can not be reshaped.
• Are harder and more resilient than
  thermoplastics.
• Non recyclable

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Plastic bags

• HUGE negative effect on the planet
• http//www.earthday.net/plasticbags

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Degradation of plastic
CAUSES DESCRIPTION
PENETRATION BY A LIQUID Liquid substances and some solutions can penetrate certain plastics and make them degrade.
OXIDATION Oxygen and other gases can react with the polymers in certain plastics to make them degrade.
UV RAYS UV rays can damage plastic polymers.
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Pollution

• http//video.google.com/videoplay?docid3892310789
  953943147
• http//video.google.com/videoplay?docid3892310789
  953943147docid-1430005279349626334

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Composites

• Definition formed by combining materials from
  different categories to obtain a material with
  enhanced properties.
• 2 parts
• The matrix the skeleton that gives it its shape
• The reinforcement inserted into the matrix to
  strengthen it

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Composites

• Gives the material properties of both substances
  to enhance it.
• Ex. Plastic reinforced with fibreglass

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Composites

• Each composite has its own characteristics, based
  on the matrix and the reinforcement.
• Many uses
• Aeronautical industry
• The sports sector
• The arts
• The mechanical industry
• The military/police

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Degradation of composites

• Deformation or fracture of the matrix or
  reinforcements (cracking).
• loss of adherence between the matrix and
  reinforcements (separating).

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Landfills

• http//videos.howstuffworks.com/hsw/16988-the-garb
  age-story-burying-garbage-in-landfills-video.htm

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Classwork

• P. 418 1-5