Materials

Question 1

Plastic Additives: Fibres

Answer 1

network of interwoven fibres /matting gives increased strength/ toughness /flexibility resulting in the polymer being able to resist greater forces / shock loads / improve strength to weight ratio.

Question 2

Plastic Additives: Stabilisers

Answer 2

• increased resistance to UV light / sunlight doesn’t fade / yellow or become brittle / increased life of product
• increased resistance to heat so does not degrade under injection moulding
• increased resistance to biological attack so will not go mouldy / have fungal growth

Question 3

Plastic Additives: Foamants

Answer 3

causes polymers to form into cellular structure / fill with bubbles / increase its volume improving the polymers volume to weight ratio / buoyancy / elasticity / flexibility / toughness / insulation properties

Question 4

Biodegradable plastic (Biopol) Advantages

Answer 4

• rots quickly so takes up less land fill space
• will not consume finite sources of oil extending supply
• sustainable - can be regrown
• reduced carbon emission, carbon absorbed in growth cycle
• organic base, non toxic
• fully renewable source
• is waterproof so has many applications - bottles
• fully degradable

Question 5

Disadvantages of biodegradable plastic (Biopol)

Answer 5

• may not be energy efficient at present so still contributing to climate change
• expensive to produce
• could lead to mono cultures to the detriment of food crops
• not widely available in present day market as isn’t cost effective

Question 6

How does Biopol break down ?

Answer 6

• exposed to micro organisms in soil/ water / sewage
• microorganisms break down the polymer
• the more micro-organism the faster the decomposition
• industrial / commercial composting systems can be used
• reduced oxygen speeds the process
• heat will speed up the process
• it takes 90 days for 90% of the plastic to degrade commercially and 2 +yrs naturally
• results in carbon dioxide and water / non toxic material