Which of the following is used in vulcanization of rubber?

• SF₆

• CF₄

• Cl₂F₂

• C₂F₂

302.

If ${\overline{\mathrm{M}}}_{\mathrm{w}}$ is the weight average molecular weight and ${\overline{\mathrm{M}}}_{\mathrm{n}}$ is the number average molecular weight of a polymer, the poly disparity index (PDI) of the polymer is given by

• $\frac{{\overline{\mathrm{M}}}_{\mathrm{n}}}{{\overline{\mathrm{M}}}_{\mathrm{w}}}$

• $\frac{{\overline{\mathrm{M}}}_{\mathrm{w}}}{{\overline{\mathrm{M}}}_{\mathrm{n}}}$

• ${\overline{\mathrm{M}}}_{\mathrm{w}} \times {\overline{\mathrm{M}}}_{\mathrm{n}}$

• $\frac{1}{{\overline{\mathrm{M}}}_{\mathrm{w}} \times {\overline{\mathrm{M}}}_{\mathrm{n}}}$

Which of the folowing is biodegradable polymer?

• Polythene

• Bakelite

• PHBV

• PVC

If the number average molecular weight and weight average molecular weight of a polymer are 40000 and 60000 respectively, the polydispersity index of the polymer will be

• >1

• <1

• 1

• zero

Which one of the following is not a biopolymer?

• Cellulose

• Nylon-6

• Insulin

• DNA

The monomer of neoprene is

• 1,3-butadiene

• 2-chloro-1,3-butadiene

• 2-methyl-1,3-butadiene

• vinyl chloride

Example of a biodegradable polymer pair is

• nylon-6, 6 and terylene

• PHBV and dextron

• bakelite and PVC

• PET and polyethylene

The polymer obtained with methylene bridges by condensation polymer is

• PVC

• buna-S

• polyacrylonitrile

• bakelite

Identify the copolymer from the following

Observe the following polymers.

I. PHBV

II. Nylon-2-nylon-6

III. Glyptal

IV. Bakelite

Biodegradable polymer(s) from the above is/ are

• III

• I and II

• IV 

• III and IV