391.

Which of the following statements is false?

• Artificial silk is derved from cellulose

• Nylon-66 is an example of elastomer

• The repeat unit  in natural rubber isoprene

• The repeat unit  in natural rubber isoprene

Which one of the following sets forms the biodegradable polymer?

• CH₂ =CH-CN and CH₂ =CH-CH=CH₂

• H₂N-CH₂-COOH and H₂N-(CH₂)₅-COOH

• HO-CH₂-CH₂-OH and 
  

• HO-CH₂-CH₂-OH and 
  

Of the following which one is classified as polyester polymer?

• Bakelite

• Melamine

• Nylon-66

• Nylon-66

Caprolactam is used for the manufacture of 

• nylon - 6

• Teflon

• terylene

• terylene

The structure of some common polymers is given. Which one is not correctly presented?

• Teflon
  
  

• Neoprene
  
  

• Terylene
  
  

• Terylene
  
  

The straight chain polymer is formed by 

• hydrolysis of (CH₃)₃ SiCl followed by condensation polymerisation

• hydrolysis of CH₃SiCl₃ followed by condensation polymerisation

• hydrolysis of (CH₂)₂Si by the addition of the polymerization

• hydrolysis of (CH₂)₂Si by the addition of the polymerization

Which one of the following statements is not true? 

• In vulcanization, the formation of sulphur bridges between different chains make rubber harder and stronger

• Natural rubber has the trans-configuration at every double bond

• Buna-S is a copolymer of butadiene and styrene

• Natural rubber is a 1,4 polymer of isoprene

Which one of the following polymers is prepared by condensation polymerization? 

• Nylon - 66

• Teflon

• Rubber

• Rubber

[NH(CH₂)NHCO(CH₂)₄CO]_n

• co-polymer

• addition polymer

• thermosetting polymer

• thermosetting polymer

Regarding cross-linked or network polymers, which of the following statements is incorrect?

• They contain covalent bonds between various linear polymer chains.

• They are formed from bi- and tri-functional monomers.

• They contain strong covalent bonds in their polymer chains.

• Examples are bakelite and melamine.