Question

Bakelite is an example of:
A. Elastomer
B. Fibre
C. Thermoplastic
D. Thermosetting polymer

Answer 1

Hint: The chemical formula of Bakelite is \[{{\left( {{\text{C}}_{\text{6}}}{{\text{H}}_{\text{6}}}\text{O}\text{.C}{{\text{H}}_{\text{2}}}\text{O} \right)}_{\text{n}}}\], with a variable molar mass and brown appearance.

Complete step-by-step answer:
Bakelite is a rigid type of plastic which is highly resistant to heat. It cannot be recycled or melted once it gets cured during the compression moulding process.
It is formed from the condensation reaction of phenol and formaldehyde.
Phenol-formaldehyde resins are obtained by the reaction of phenol and formaldehyde in the presence of either on acid or a basic catalyst. The reaction involves the formation of methylene bridges in ortho, para or both ortho and para positions. The initial product is a linear polymer called Novolac which is used in paints. Novolac on heating with HCHO undergo cross- linkage to form an infusible solid called bakelite.
Bakelite is an example of thermosetting plastic. Therefore, Option D is the correct answer.

Additional Information:
Just like any other plastic waste product, disposing Bakelite is extremely hazardous to the environment. Not only did the products contain formaldehyde, Bakelite contains asbestos, a known and hazardous toxic. Exposure to bakelite dust may cause lung infections, mesothelioma and other respiratory complications.
Thermosetting polymer, resin, or plastic often called a thermoset, is a polymer that is irreversibly hardened by curing from a soft solid of viscous liquid prepolymer or resin. Curing is induced by heat or suitable radiation and may be promoted by high pressure, or mixing with a catalyst.

Note: Bakelite is used for making combs, fountain pens, phonograph records, electrical goods etc. Soft bakelites with low degree of polymerization are used as binding blue for laminated, wooden plants and varnishes and lacquers. Sulphonated bakelites are used as ion-exchange resins.