Chemical Industry Questions and Answers for Campus interviews on “Polymerization – Fibres”.
1. What are synthetic polymeric fibres?
a) Multifunctional monomers forming three or more active covalent bonds
b) Linear chains joined one to another at various positions
c) Linear molecules formed by extrusion
d) Polymers with side branches
Answer: c
Clarification: Synthetic polymeric fibres are linear molecules formed by extrusion or spinning into small diameter. Network polymers are multifunctional monomers forming three or more active covalent bonds.
2. How is synthetic polymeric fibres made?
a) Spinning
b) Weaving
c) Filamenting
d) Attrition
Answer: a
Clarification: Synthetics are prepared from molten linear polymers or a solution of polymers by extrusion through a die containing 20 to 15000 small holes, solidifying and collecting a group of threads as a filament.
3. Which sector of textile industry is called worsted industry?
a) Cotton
b) Linen
c) Wool
d) Nylon
Answer: c
Clarification: Wool sector of the textile industry is better known as worsted industry, as its main product is suiting-all wool (AW), polyester wool (PW) and polyester viscose.
4. Which among the following is known as poor man’s silk?
a) Wool
b) Cotton
c) Linen
d) Viscose
Answer: d
Clarification: Viscose rayon is more commonly known as poor mans silk due to its vast material application and is cost effective.
5. Viscose is a weak fibre.
a) True
b) False
Answer: a
Clarification: Viscose suffers from major deficiencies, therefore it’s a weak fibre especially when its wet. It generates toxic effluents during its manufacture.
6. What is the main raw material of Viscose rayon?
a) Bagasse
b) Sugar
c) Wood pulp
d) Polyester
Answer: c
Clarification: The main raw material for the manufacture of viscose rayon includes wood pulp, other strengthening additives. Its production produces toxic effluents.
7. Which is the most commonly used dying fibre?
a) Rayon
b) Nylon
c) Polyester
d) Viscose
Answer: b
Clarification: Nylon is most commonly used dying fibre because of its excellent dying properties and its cost effective.
8. How is cellulose manufactured in industry?
a) Xanthate process
b) Contact process
c) Monte carteni process
d) Natural process
Answer: a
Clarification: Cellulose is produced by viscose or xanthate process, with the cuprammonium produced contributing only minor production.
9. What are the series of steps involved in viscose process?
a) Alkali conversion-Solubilization-Acid regeneration
b) Acid regeneration-Solubilization-Alkali conversion
c) Solubilization-Acid Regeneration-Alkali conversion
d) Acid Regeneration-Alkali conversion-Solubilization
Answer: a
Clarification: Initially the cellulose reacts with NaOH to form alkali cellulose which undergoes solubilization by CS2 and then gets converted to cellulose by the addition of acid.
10. 6,6 Nylon is manufactured from ____________
a) polyethylene
b) polyester
c) adipic acid
d) sulfuric acid
Answer: c
Clarification: 6,6 Nylon is manufactured from adipic acid. This adipic acid then reacts with hexamethylene diamine to form polyhexamethylene adipamide or 6,6 nylon.
11. Which among the following is the major component of acrylic fibres?
a) Polyacrylonitrile
b) Monoacrylonitrile
c) Polyester
d) Polyethylene
Answer: a
Clarification: Acrylics constitute one of the four major classes of synthetic fibres. Polyacrylonitrile is the major component of acrylic fibres. A comonomer is generally incorporated to improve such fibre properties.