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

145.

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.

Polymer formation from monomers starts by

• condensation reaction between monomers

• coordination reaction between monomers

• Conversion of one monomer into other monomers

• hydrolysis of monomers

Which of the following fibres is made of polyamides?

• Dacron

• Orion

• Nylon

• Rayon

Consider the following reaction,

$$\begin{gathered} \mathrm{X} \stackrel{\mathrm{Bromination}}{\to } \mathrm{Y} \underset{+ \mathrm{HCl}}{\overset{{\mathrm{NaNO}}_2}{\to }} \mathrm{Z} \\ \mathrm{Z} \underset{{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}}{\overset{\mathrm{Boiling}}{\to }} \mathrm{Tribromo} -\mathrm{benzene} \mathrm{X} \mathrm{is} \end{gathered}$$

• benzoic acid

• salicylic acid

• Phenol

• Aniline

Which of the following statements is incorrect?

• Polypropylene is a thermoplastic polymer

• Melamine-formaldehyde is a thermosetting polymer

• Mixture of styrene and methyl methacrylate can form ionic addition polymer

• Low-density polythene is a poor conductor of electricity

Polypropylene can be obtained by polymerisation of

• CH₂ $=$ CH - CH₂ - Cl

• CH₂ $=$ CH - Cl

• CH₃ - Cl

• CH₃ - CHCl₂