alkenes

Question 1

poly(chloroethene)

Answer 1

• also known as poly(vinyl chloride) or PVC.
• can be prepared to make a polymer that is flexible or rigid eg used for pipes and bottles, flooring, ducts and profiles

Question 2

recycling

Answer 2

• reduces environmental impact by conserving finite fossil fuels as well as decerasing the amount of waste going into landfill
• discarded polymers have to be sorted by type
• once sorted polymers are chopped into flakes, washed, dried and melted. Recycled polymers are cut into pellets and used to make new products

Question 3

PVC recycling

Answer 3

• disposal of PVC is harzadous due to high chlorine content and range of additivies present in the polymer. Dumping PVC in landfill isnt sustainable, and when burnt, PVC releases HCl a corrosive gas and other pollutants like toxic dioxins
• recycling involves grinding PVC and reusing it to manufacture new products
• new technology uses solvents to dissolve the polymer. High- grade PVC is then recovered by precipitation from the solvent and the solvent is used again
• removal of toxic waste products, e.g.
  removal of HCl formed during disposal by
  combustion of halogenated plastics
  (e.g. PVC)

Question 4

using waste polymers as fuel

Answer 4

• waste polymers can undergo combustion for energy production

Question 5

feedstock recycling

Answer 5

• chemical and thermal process that can reclaim monomers, gases or oil from waste polymers. The materials can be used as raw materials for the production of new polymers
• • able to handle unsorted and unwashed polymers
• used as organic feedstock for the production of plastic and other organic materials

Question 6

biodegradable polymers

Answer 6

• bioplastics produced from plant starch, cellulose, plant oils and proteins offer a renewable and sustainable alternative to oil-based products. Protects environment and conserves oil reserves
• biodegradable polymers are broken down by microorganisms into water, CO2 and biological compounds. Compostable polymers degrade and leave no visible or toxic residues. Compostable polymers based on poly(lactic acid) are becoming more common as an alterative to alkene- based polymers

Question 7

photodegradable polymers

Answer 7

polymers contain bonds that are weakened by absorbing light to start the degradation