Polymers

Question 1

What is PHBV?

Answer 1

Poly B-hydroxy butyrate -co-B-hydroxy valerate

PHBV is a biodegradable polymer useful in manufacturing capsules and packing orthopedic devices.

Question 2

What is vulcanization of rubber?

Answer 2

The process of heating raw rubber with sulphur at 373-415 K to improve its physical properties

Vulcanization introduces ‘sulphur bridges’ between polymer chains, enhancing tensile strength, elasticity, and resistance to abrasion.

Question 3

What are copolymers?

Answer 3

Polymers formed from two or more types of monomers by addition or condensation

Example: Buna-S is a copolymer of 1,3-butadiene and styrene.

Question 4

What is polymerization?

Answer 4

The process of formation of polymer from its constituent monomers

Example: Polymerization of ethene forms polyethene.

Question 5

What is the value of PDI for polymers?

Answer 5

The value of PDI lies between 1 and 1.5

PDI is the ratio between ‘weight average molecular mass’ (M_w) and ‘number average molecular mass’ (M_n) of a polymer.

Question 6

What is a biodegradable polymer?

Answer 6

Polymers that decompose by themselves in biological systems over time due to enzymatic hydrolysis or oxidation

Example: PHBV.

Question 7

What is the Ziegler-Natta catalyst?

Answer 7

Triethylaluminium and titanium tetrachloride (C2H5)3Al-TiCl4

Used in the preparation of high-density polyethylene.

Question 8

Fill in the blank: Vulcanization introduces _______ between polymer chains.

Answer 8

sulphur bridges

Question 9

True or False: PHBV is a non-biodegradable polymer.

Answer 9

False