Question

Which of the following statements is true about PVC (polyvinyl chloride) and polythene?
A.They are thermoplastics
B.They are thermosetting plastics
C.They are examples of natural substances
D.They are natural fibres

Answer 1

Hint: Both of these plastic polymers are obtained by chemical processing of different monomers and change shape on heating.

Complete step by step answer:
Before we move forward with the solution of the given question, let us first discuss some important basic concepts.
Thermoplastics: Thermoplastics can be identified as those plastics polymers which are softened by heating and hardened by cooling. This can simply be transliterated as these polymers have the capacity of changing shape and form if sufficient amount of heat is supplied to the system
Thermosetting plastics: Thermosetting plastics have the exact opposite characteristics when compared to thermoplastics. This means that these plastic polymers do not change shape or form when heat is provided to the system. Instead, they tend to burn out in the process.
Natural Substances: Natural substances are those which are obtained directly from nature and are used with little or no processing.
Natural Fibres: Natural Fibres are a part of natural substances. These fibres require some processing before being put into direct use.
Now let us discuss the given polymer plastics \[-PVC\] and polythene. Both of these plastic polymers are obtained by chemical processing of different monomers. Hence, they are not naturally available substances. As for the discussion whether they are thermosetting or thermoplastic, we can deduce this firm fact that they change shape and form upon heating.
Hence, PVC (polyvinyl chloride) and polythene are thermoplastics.

Hence, Option A is the correct option.

Note:
Both PVC and polythene are used in a wide range of products including plastic consumer goods like containers, rain covers, plastic bags, water pipes, etc. Polythene is further classified on the basis of the density of its different forms like LDPE, HDPE, etc.