Chemistry

Polymers and Plastics

1,228 Questions

Polymers and plastics questions explore the properties, synthesis, and applications of various synthetic and natural polymers. Key topics include biodegradable plastics, vulcanization, and polymer nanocomposites. These concepts are frequently tested in science and engineering competitive exams.

Biodegradable plasticsPolymer nanocompositesVulcanization of rubberPolymer molecular weightAsphalt binders

Polymers and Plastics Questions

Multiple choice

Which of the following statements about polycarbonate are false? P. Manufactured by the reaction bis-phenol A with phosgene. Q. Belongs to the group of linear thermoplastic polyesters. R. It is highly opaque. S. Glass transition temperature of about 200°C. Select the correct answer using codes given below:

  1. P and Q

  2. P and R

  3. P and S

  4. Q and R

  5. R and S
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Polycarbonate is highly transparent to visible light, with better light transmission than many kinds of glass. Polycarbonate has a glass transition temperature of about 147°C, so it softens gradually above this point and flows above about 155°C.

Multiple choice

Which of the following compounding ingredients are used as fillers in plastic technology?

  1. Calcium carbonate
  2. Aluminium hydroxide
  3. Tricresyl phosphate
  4. p-toluenesulfonylhydrazide Select the correct answer using codes given below:

  1. 1 and 2

  2. 1 and 4

  3. 2 and 3

  4. 2 and 4

  5. 3 and 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Calcium carbonate is mainly used as filler in the plastics sector. Aluminium hydroxide also finds use as fire retardant filler for polymer applications.

Multiple choice

Which of the following compounding ingredients are used as blowing agents for polymers?

  1. Calcium carbonate
  2. Zinc carbonate
  3. 5-phenyltetrazole
  4. Azodicarbonamide Select the correct answer using codes given below:

  1. 1 and 2

  2. 1 and 4

  3. 1, 2 and 3

  4. 2, 3 and 4

  5. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Zinc carbonate is an inorganic chemical blowing agent which decomposes at higher temperature than bicarbonates. 5-phenyltetrazole (5-PT) has been widely used as a blowing agent for foaming high temperature-processing polymers. The principal use of azodicarbonamide is in the production of foamed plastics as a blowing agent.

Multiple choice

Which of the following are examples of plasticizers?

  1. Triethyl citrate
  2. Dibutyl sebacate
  3. Polybutene
  4. Benzylbutylphthalate Select the correct answer using codes given below:

  1. 1 and 2

  2. 1, 2 and 4

  3. 2 and 3

  4. 2, 3 and 4

  5. 1, 2, 3 and 4
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Triethyl citrate is used as a plasticizer for polyvinylchloride and similar plastics. Dibutyl sebacate is a dibutyl ester of sebacic acid. Its main use is as a plasticizer in production of plastics such as cellulose acetate butyrate, cellulose acetate propionate, ethyl cellulose, polyvinyl butyral, polyvinyl chloride, polystyrene, and many synthetic rubbers and other plastics. Polybutene and polyisobutylene are liquid oligomers widely used as plasticizers for high-molecular weight polymers, such as polyethylene. Benzylbutylphthalate (BBzP) is an ester of phthalic acid, benzyl alcohol and n-butanol. It is mostly used as a plasticizer for PVC.

Multiple choice

Match the following compounding ingredients in plastic technology with their respective functions.

 
Compounding ingredients
Functions
P. Sodium bicarbonate 1. Pigment
Q. Dioctyl phthalate 2. UV stabilizer
R. Titanium dioxide 3. Blowing agent
S. Phenyl salicylate 4. Plasticizer

  1. P - 3, Q - 1, R - 4, S - 2

  2. P - 1, Q - 4, R - 3, S - 2

  3. P - 4, Q - 1, R - 2, S - 3

  4. P - 3, Q - 4, R - 1, S - 2

  5. P - 2, Q - 4, R - 1, S - 3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sodium bicarbonate is commonly used as a blowing agent in the manufacture of rigid foams which are chiefly polystyrene polyurethane, epoxy, and polyvinyl chloride. Dioctyl phthalate (DOP) is the most common of the class of phthalates which are used as plasticizers. Titanium dioxide is the most important white pigment used in the polymer industry. Phenyl salicylate is used as UV stabilizer for commercial polymers and sun tanning lotions.

Multiple choice

Which of the following sets represents copolymers only?

  1. Glyptal, Buna-S, Nylon 66, Dacron

  2. Polystyrene, Neoprene, Nylon 6, Dacron

  3. Buna-S, Neoprene, Glyptal, Nylon 6

  4. Buna-S, Dacron, Nylon 6, Nylon 66

  5. Neoprene, Glyptal, Nylon 66, Polystyrene
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Glyptal is a copolymer of ethylene glycol and phthalic acid. Buna S is a copolymer of 1,3-butadiene and styrene. Nylon 66 is a copolymer of hexamethylene diamine and adipic acid. Dacron is a copolymer of ethylene glycol and terephthalic acid.

Multiple choice

Which of the following statements are false? P. Thermosetting polymers cannot be recycled. Q. Elastic deformation in polymers is due to slippage of molecular chains. R. High-density polyethylene is less crystalline than low-density polyethylene. S. Elastomers consist of coil-like polymer chains. Select the correct answer using codes given below:

  1. P and Q

  2. P and R

  3. Q and R

  4. Q and S

  5. R and S
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Elastic deformation in polymers is due to slight adjustment of molecular chains. High-density polyethylene is more crystalline than low-density polyethylene because it contains fewer branches.

Multiple choice

Which of the following is a pair of biodegradable polymers?

  1. Nylon 6, 6 and Nylon 2–nylon 6

  2. Nylon 6, 6 and PHBV

  3. PVC and PHBV

  4. PHBV and Nylon 2–nylon 6

  5. Nylon 2–nylon 6 and PVC
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Poly β - hydroxybutyrate - co - β - hydroxy valerate (PHBV) is a biodegradable polymer obtained by the copolymerisation of 3–hydroxybutanoic acid and 3–hydroxypentanoic acid. Nylon 2–nylon 6 is an alternating polyamide copolymer of glycine and amino caproic acid and is biodegradable.

Multiple choice

Which of the following is a set of elastomers?

  1. Buna-S, Buna-N, Neoprene

  2. Nylon 66, Terylene, bakelite

  3. Buna-S, Buna-N, Nylon 66,

  4. Neoprene, Terylene, Bakelite

  5. Nylon 66, Neoprene, Terylene
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Buna S, Buna N and Neoprene: All are the examples of elastomers.

Multiple choice

The polymer of isoprene is called

  1. natural rubber

  2. Polyethylene

  3. neoprene

  4. monoprene
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Natural rubber is a polymer of isoprene (2-methyl-1,3-butadiene). The polymerization of isoprene molecules forms polyisoprene, which is the chemical composition of natural rubber obtained from rubber trees. The other options are different synthetic polymers - polyethylene is from ethylene, neoprene is chloroprene rubber, and monoprene is not a standard polymer.

Multiple choice

Which among the following statements is not true?

  1. Biopolymers are a special class of polymers found only in living organisms.

  2. Starch, proteins and peptides, DNA, and RNA are all examples of biopolymers.

  3. Both, polymers and biopolymers, are made of repetitive units called monomers.

  4. Biopolymers can not fold into characteristic compact shapes.

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The question asks which statement is NOT true (i.e., false). Option D claims biopolymers cannot fold into characteristic compact shapes, but this is incorrect - biopolymers like proteins fold into complex 3D structures, DNA coils into helices, and RNA forms specific tertiary structures. Therefore, D is indeed a false statement and is the correct answer. Options A, B, and C are all true statements about biopolymers.