Polymers

Question 1

SOME TOPICS ARE SKIPPED

Answer 1

SOME TOPICS ARE SKIPPED

Question 2

types of polymerisation

Answer 2

addition(chain growth)
condensation(step growth)

Question 3

Name eg of addition polymerisation

Answer 3

Polythene
PVC - polyvinyl chlroide
PAN - polyacrocylonitrile
Polystyrene
Polybutadiene
Polyisoprene
Synthetic rubber
Teflon/PTFE - polytetraflouraethene

Question 4

Name eg of condensation polymers

Answer 4

Polyamide
polyester
phenol formaldehyde polymers
polyamides

Question 5

Polythene

Answer 5

n(CH2=CH2) –> -(-CH2–CH2-)-

Question 6

PVC

Answer 6

n(CH2=CHCl) → -(-CH2-CHCl-)-

Question 7

PAN

Answer 7

n(CH2=CH-CN) → -(-CH2-CH(CN)-)-

Question 8

Polystyrene

Answer 8

n(CH2=CH–C6H5) → -(-CH2–CH(C6H5)-)-

Question 9

polybutadiene

Answer 9

n(CH2=CH–CH=CH2) → -(-CH2–CH=CH–CH2-)-

Question 10

Polyisoprene

Answer 10

n(CH2=C(CH3)–CH=CH2) → -(-CH2–C(CH3)=CH–CH2-)-

this can show GI

Question 11

Synthetic rubber

Answer 11

chloroprene to neoprene
n(CH2​=CCl−CH=CH2​)→−(−CH2​−CCl=CH−CH2​−)−

BUNA S - copolymer of butadiene and styrene
BUNA N - copolymer of Butadiene and Acrylonitrile

Question 12

Teflon/ PTFE

Answer 12

n(CF2=CF2) → -(-CF2–CF2-)-

Question 13

Polyamides

Answer 13

-COOH + NH2- becomes(-H2O) - CO - NH

examples
Nylon 6,6
Nylon 2,6
Nylon 6,10

Question 14

Poly ester

Answer 14

-COOH + -OH becomes(-h2o) -CO-O-
examples
PET

Question 15

What is vulcanisation of natural rubber?

Answer 15

Heating natural rubber with sulfur (around 140-160°C) to form cross-links (–S–S– bonds) between polymer chains, improving elasticity, strength, and durability.

Question 16

HDPE vs LDPE

Answer 16

HDPE: High Density, linear chains, less branching, stronger & more crystalline, higher melting point (~130°C).

LDPE: Low Density, highly branched chains, less crystalline, softer & more flexible, lower melting point (~110°C).

Question 17

polymer classifications based on source

Answer 17

Natural polymers: Found in nature (e.g., natural rubber, cellulose).

Synthetic polymers: Man-made from monomers (e.g., nylon, polystyrene).

Semi-synthetic polymers: Modified natural polymers (e.g., cellulose acetate).

Question 18

polymers classified by structure

Answer 18

Linear polymers: Chains without branches (e.g., HDPE).

Branched polymers: Chains with side branches (e.g., LDPE).

Cross-linked polymers: Chains connected by covalent bonds (e.g., vulcanised rubber, Bakelite).

Question 19

Polymer types by forces & thermal properties

Answer 19

Elastomers: Soft, elastic, lightly cross-linked (e.g., natural rubber).

Fibers: Strong intermolecular forces, oriented chains (e.g., nylon, polyester).

Thermoplastics: Can be melted & reshaped (e.g., polyethylene, polystyrene).

Thermosetting plastics: Cross-linked, hard, don’t melt on heating (e.g., Bakelite).