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Polymer Science and Technology

Description: Polymer Engineering Sciences - XE
Number of Questions: 20
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Tags: Polymer Engineering Sciences - XE
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Which of the following are examples of amorphous thermoplastics?

  1. Polymethylpentene
  2. Polyphenylene ether
  3. Polyetherimide
  4. Polyphenylenesulphide
  5. Polyamidimide
  6. Polypropylene Select the correct answer using codes given below:
  1. 1, 2 and 5

  2. 2, 3 and 5

  3. 2, 4 and 6

  4. 3, 5 and 6

  5. 4, 5 and 6


Correct Option: B
Explanation:

Polyphenylene ether (PPE) is an amorphous standard thermoplastic polymer. Polyetherimide (PEI) is an amorphous thermoplastic with high mechanical strength and rigidity. Polyamidimides (PAI) are amorphous thermoplastic high performance polymers characterized by high thermal stability.

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


Correct Option: E
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.

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


Correct Option: A
Explanation:

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

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


Correct Option: D
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.

Which of the following polymers has highest glass transition temperature (Tg)?

  1. LDPE

  2. PVC

  3. PHB

  4. PET

  5. PTFE


Correct Option: E
Explanation:

Glass transition temperature (Tg) of polytetrafluoroethylene (PTFE) is 115oC.

Match the column – I (Polymer) with column – II (Application) and select the correct option.

 
Column – I
Column – II
A. Polysulfone 1. Ball bearing cages
B. Polycarbonate 2. Filtration media
C. Acrylonitrile butadiene styrene 3. Pototyping extrusion-based 3D printers
D. Nylon 6-6 4. Compact Disc
  1. A - 1, B - 2, C - 3, D - 4

  2. A - 1, B - 3, C - 4, D - 2

  3. A - 2, B - 4, C - 3, D - 1

  4. A - 2, B - 4, C - 1, D - 3

  5. A - 3, B - 1, C - 2, D - 4


Correct Option: C
Explanation:

Polysulfone is used as filtration media. The pore size can be very small, down to 0.2 µm or less for use in filter sterilization. A major application of polycarbonate is the production of Compact Discs, DVDs, and Blu-ray Discs. Acrylonitrile butadiene styrene (ABS) is commonly used in rapid prototyping extrusion-based 3D printers. Nylon 6-6 is frequently used when high mechanical strength, great rigidity, and good stability under heat is required. It is used for ball bearing cages, electro-insulating elements, pipes, profiles and various machine parts.

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


Correct Option: E
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.

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


Correct Option: D
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.

Which of the following is not an example of semi-crystalline thermoplastic polymer?

  1. Polyetherimide

  2. Polyether ether ketone

  3. Polystyrene

  4. Polycarbonate

  5. Polyvinyl chloride


Correct Option: B
Explanation:

Polyether ether ketone (PEEK) is a semicrystalline thermoplastic polymer with excellent mechanical and chemical resistance properties that are retained to high temperatures.

Which of the following are examples of thermosetting polymers?

  1. Bakelite
  2. Polyurethanes
  3. Epoxy resin
  4. Polysulfone
  5. Polyethylene terephthalate Select the correct answer using codes given below:
  1. 1, 2 and 3

  2. 1, 3 and 5

  3. 2, 3 and 4

  4. 2 and 4

  5. 4 and 5


Correct Option: A
Explanation:

Bakelite, polyurethanes, epoxy resin: All are examples of thermosetting polymers

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


Correct Option: A
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.

Which of the following is/are example(s) of semi-crystalline polymers?

  1. Polyvinyl chloride
  2. Polytetrafluoroethylene
  3. Polyvinyl butyral Select the correct answer using codes given below:
  1. 1 only

  2. 2 only

  3. 3 only

  4. 1 and 2

  5. 1 and 3


Correct Option: B
Explanation:

Polytetrafluoroethylene (PTFE) is a semi-crystalline high performance thermoplastic.

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


Correct Option: C
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.

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


Correct Option: D
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.

Match the column – I (polymer) with column – II (m.p.,oC) and select the correct option.

 
Column – I (Polymer)
Column – I (Tm)
P. Polyvinyl alcohol 1. 175oC
Q. Teflon 2. 230oC
R. Dacron 3. 260oC
S. Delrin 4. 326.8oC
  1. P - 3, Q - 2, R - 4, S - 1

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

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

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

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


Correct Option: E
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.

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


Correct Option: A
Explanation:

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

Match the column – I (additives for plastics) with column – II (its function) and select the correct option.

 
Column – I
Column – I
P. Sulphur 1. Vulcanizing activator
Q. Chlorendic acid 2. Vulcanisation agent
R. Polyisobutylene 3. Plasticizer
S. Zinc oxide 4. Flame retardant
  1. P - 1, Q - 2, R - 3, S - 4

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

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

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

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


Correct Option: B
Explanation:

Elemental sulphur is the most widely used vulcanisation agent in the rubber industry. Polyisobutylene is a liquid oligomer widely used as plasticizer for high-molecular weight polymers, such as polyethylene. Chlorendic acid is used as an intermediate in synthesis of unsaturated flame-retardant polyester resins and plasticizers, and as a finishing flame-retardant treatment for wool. Zinc oxide (ZnO) is the most known vulcanizing activator.

In the following question there are two statements, Assertion (A) and Reason (R), consider both the statements independently and mark your answers as under:

  1. If both A and R are correct and R is correct explanation of A.
  2. If both A and R are correct and R is not correct explanation of A.
  3. If A is correct and R is incorrect.
  4. If A is incorrect and R is correct.
  5. If both A and R are incorrect. Assertion (A) : Natural rubber is a cis - 1, 4 - polyisoprene. Reason (R) : On vulcanization, rubber becomes softer.
  1. 1

  2. 2

  3. 3

  4. 4

  5. 5


Correct Option: C
Explanation:

Assertion statement is true, but reason statement is false. Natural rubber may be considered as a linear polymer of isoprene (2 - methyl - 1, 3 butadiene) and is also called as cis - 1, 4 - polyisoprene. On vulcanization, sulphur forms cross links at the reactive sites of double bonds and thus the rubber gets stiffened.

Match the column – I (polymer) with column – II (application) and select the correct option.

 
Column – I
Column – II
P. Melamine formaldehyde polymer 1. Non-stick surface coated utensils
Q. Teflon 2. Unbreakable crockery
R. Polyacrylonitrile 3. Paints and lacquers
S. Glyptal 4. Substitute for wool
  1. P - 1, Q - 2, R - 3, S - 4

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

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

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

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


Correct Option: C
Explanation:

Melamine formaldehyde polymer is used in the manufacture of unbreakable crockery. Teflon is used in making oil seals and gaskets and also used for non-stick surface coated utensils. Polyacrylonitrile is used as a substitute for wool in making commercial fibres as orlon or acrilan. Glyptal is used in manufacture of paints and lacquers.

Match entries in column – I with that in column – II and select the correct option.

 
Column – I
Column – II
A. Linear polymer 1. High density polythene
B. Branched chain polymer 2. Low density polythene
C. Cross linked polymer 3. Bakelite
  1. A - 1, B - 2, C - 3

  2. A - 1, B - 3, C - 2

  3. A - 2, B - 1, C - 3

  4. A - 2, B - 3, C - 1

  5. A - 3, B - 1, C - 2


Correct Option: A
Explanation:

Linear polymers consist of long and straight chains. The examples are high density polythene, polyvinyl chloride, etc. Branched chain polymers contain linear chains having some branches, e.g. low density polythene. Cross linked or Network polymers are usually formed from bi-functional and tri-functional monomers and contain strong covalent bonds between various linear polymer chains, e.g. bakelite, melamine, etc.

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