Polymer Technology

A. Denier is defined as weight in gm of 9000 metres length of a fibre, while tex is defined as weight in gm of 1000 metres length of fibre
B. Crimp is a measure of the difference between the length of the straightened and unstraightened fibre
C. Dacron fibres, acrylic fibres, viscose rayon fibres & cellulose acetate fibres are all prepared by wet spinning
D. Nylon fibres have greater water absorption capacity than polyester fibres

A. Polystyrene is a thermoplastic polymer
B. Protein is a natural polymer
C. Neoprene is a natural rubber
D. Polythene is a copolymer, while SBR is a homopolymer

A. Polymers made of only one monomer is called homopolymer
B. Polymers made of more than one monomer is called copolymer or mixed polymer
C. Vulcanised rubber is more elastic than natural rubber
D. The intermolecular forces in thermoplastic polymers are intermediate to that of elastomers &
fibres

A. Addition polymers are generally formed by chain growth polymerisation
B. Condensation polymers are generally formed by step growth polymerisation
C. Teflon is formed by step growth polymerisation
D. Bakelite is formed by step growth polymerisation

A. Polymeric fibres are never produced by addition polymerisation
B. Property of tackiness is exhibited by uncured rubber
C. Sharp melting point is not observed in thermoplastic polymers
D. Polythene generally has an excellent resistance to ultra violet rays

A. Linear polymers are formed from bifunctional groups only and are normally thermoplastic
B. Cross-linked branched chain polymers are either elastometric or thermosetting
C. Branching in case of cross-linked polymers caused by small amount of impurities in
bifunctional monomer formulation reduces its solubility and increases the softening point
D. Dibasic acids reacts with dihydric alcohols to give polyesters using addition polymerisation
reaction

A. Cold SBR is superior as compared to hot SBR
B. Polymerisation temperature can modify the properties of SBR
C. Production of cold SBR employs lower pressure as compared to that of hot SBR
D. None of these

A. Polyurethane
B. SBR
C. Teflon
D. Bakelite

A. Teflon
B. Bakelite
C. SBR
D. None of these

A. Low temperature thermal insulation as in refrigerator and air conditioners
B. Acoustic control and ceiling for building
C. High temperature thermal insulation in furnaces
D. Packing of delicate electronic gadgets