Question

Which of the following is a thermosetting polymer?
A. Buna-N
B. PVC
C. Bakelite
D. Nylon 6

Answer 1

. Thermosetting polymer, resins, or plastics, often called a thermoset, is a type of polymer that is irreversibly hardened by curing from a soft solid or viscous liquid prepolymer or resins. Curing is done by the application of heat or suitable radiation and it is possible to amplify it by high pressure, or mixing it with a catalyst.

Complete step by step answer:
A thermosetting polymer which is also called a thermoset or thermosetting plastic is a polymer whose structure is made up of cross linkings of molecules that have heavy branching.
These polymers which are in the soft solid or viscous state of heating undergo extensive cross-linking in moulds and become irreversibly hard as well as insoluble products.

The eight most common types of synthetic organic polymers, which are commonly found in households, and some in industries too are as follows:
Low-density polyethylene (LDPE)
High-density polyethylene (HDPE)
Polypropylene (PP)
Polyvinyl chloride (PVC)
Polystyrene (PS)
Teflon (Polytetrafluoroethylene)
Thermoplastic polyurethanes (TPU)

Now Bakelite is a cross linked polymer which after heating can not be recovered in its original structure. Hence it is a thermosetting polymer. Rest all are thermoplastic polymers.
Thermoplastic polymers can be classified as amorphous or crystalline. Most thermoplastics suitable for use as matrices for high performance composite exhibits some degree of crystallinity because this type of structure has better resistance to chemical attack by field, hydraulic oil and paint stripper.
All the plastic materials which can be softened and melted by heating but they set again when cool are known as thermoplastics.
So the answer will be bakelite which goes with option C.
So, the correct answer is “Option C”.

Note: Some Common examples of thermosetting plastics and polymers consists of epoxy, silicone, polyurethane and phenolic. Bakelite is known to be the first plastic that is said to be made with completely synthetic components. It has the chemical formula $({{C}_{6}}-{{H}_{6}}-O.C-{{H}_{2}}-O)x$.