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Questions Related to man made materials

Multiple choice chemistry man made materials environmental impact: plastics plastic plastic plastic waste garbage in, garbage out

Which of the following are not thermosetting polymers ?

  1. Bakelite

  2. polystyrene

  3. PVC

  4. Melmac

Reveal answer Fill a bubble to check yourself
B,C Correct answer
Explanation

Thermosetting polymers have different properties to thermosoftening polymers. Once moulded, they do not soften when heated and they cannot be reshaped. Vulcanised rubber is a thermoset used to make tyres. Its polymer chains are joined together by cross-links, so they cannot slide past each other easily.


Examples are given below:
  • Polyester fibreglass systems: sheet molding compounds and bulk molding compounds
  • Polyurithane insulating foams, mattresses, coatings, adhesives, car parts, print rollers, shoe soles, flooring, synthetic fibers, etc. Polyurethane polymers are formed by combining two bi- or higher functional monomers/oligomers.
  • Vulcanized rubber
  • Bakelite, a phenol formaldehyde resin used in electrical insulators and plasticware
  • Duroplast, light but strong material, similar to bakelite used for making car parts


Polyvinyl chloride(PVC) and polystyrene are thermoplastic polymer.
Hence, options B and C are correct.