The given question asks about the polymer formed when Novolac is heated with formaldehyde. To find the correct answer, let's examine each option and understand the chemical process involved:
Novolac and Bakelite:
Novolac is a type of phenol-formaldehyde resin, and it is not thermosetting. When heated with formaldehyde, Novolac undergoes a cross-linking reaction to form Bakelite. This process involves further polymerization under heat and pressure, converting the resin into a hard, rigid, and thermosetting polymer known as Bakelite. Therefore, Bakelite is formed as a result of heating Novolac with formaldehyde.
Melamine:
Melamine is formed from urea through a series of reactions, and it does not involve Novolac or formaldehyde in its synthesis. Thus, Melamine is not the correct answer.
Polyester:
Polyesters are a class of polymers formed by the reaction of diacids with diols. They do not involve phenol or formaldehyde, which are essential in forming Bakelite. Therefore, Polyester cannot be formed by heating Novolac with formaldehyde.
Nylon 6,6:
Nylon 6,6 is a synthetic polymer made from hexamethylenediamine and adipic acid. This polymer does not involve the use of Novolac or formaldehyde. Therefore, Nylon 6,6 cannot be the polymer formed in this case.
Based on the explanation above, the correct answer is Bakelite, formed by the reaction of Novolac with formaldehyde through heat and pressure.
