Question

Which of the following does not use formaldehyde in its preparation?
A.Melamine polymer
B.Bakelite
C.PHBV
D.Preservation of biological specimens

Answer 1

Hint:The polymer which is not prepared using formaldehyde as monomer is biodegradable and non toxic plastic that is produced naturally by bacteria. It is a good alternative over the non biodegradable synthetic polymer.

Complete step by step answer:
Melamine resin is also known as melamine formaldehyde resin and is also generally called melamine. It is a thermosetting plastic material which is made from melamine and formaldehyde. Melamine is a polymer of formaldehyde and hence uses formaldehyde in its preparation.
Bakelite is the name for the compound polyoxybenzylmethylenglycolanhydride. It is also a thermosetting polymer made using formaldehyde and phenol. It is a condensation polymer. Condensation polymers are those polymers which are formed by the release of some smaller solvent molecules like water.PHBV is the abbreviation for polyhydroxy butyrate hydroxy valerate . It is also a thermoplastic polymer. It is majorly used in medicines for the packing of medicine and drugs. It is also used in capsules, to form the upper layer of the capsule. Monomers are 3 hydroxybutanoic acid and 3 hydroxypentanoic acid. It does not use formaldehyde as a polymer as a monomer in its preparation.
Formaldehyde is used as a preservative for the preservation of biological species as it prevents the growth of bacteria and other pathogens and kills microorganisms which helps in extending the shelf life of the product.
Formaldehyde is used for all the given options except in the preparation of PHBV.

Hence the correct option is option C.

Note:
Thermoplastic is a plastic polymer material that becomes mouldable at a certain high temperature and again solidifies upon cooling. They usually have a high molecular weight. Thermosetting plastics are not re-moldable once they are moulded into desired shapes.