Perlon is Nylon-6. It is prepared from a single monomer having a potential amino group at one end and a potential carbonyl group at other end.
What is the percentage of sulphur used in vulcanization of rubber
Solution
Vulcanization is a process in which natural rubber is treated with sulphur and certain organic compounds which accelerate the reaction between the rubber and sulphur.Thus about 5% S is used for making tyre rubber, 20-25%S for making ebonite and 30% S for making battery case rubber.
Which of the following is used in vulcanization of rubber ?
Solution
SF6 is used in the vulcanisation of rubber. Sulphur is heated with polymer to introduce cross-linking and thus,form tough polymer
Given the polymers
(i) Nylon-66;
(ii) Buna-S;
(iii) Polythene,arrange these in increasing order of their inter-molecular forces (lower to higher)
Solution
Nylon 6, 6 is a fibre with hydrogen bonds thus have strongest intermolecular forces. Buna-S is a elastomer whereas polythene is thermoplastic. the intermolecular forces of attraction in thermoplastics is intermediate between elastomer and fibres. Therefore forces in elastomers are weakest.
Characteristic property of Teflon is
Solution
Teflon is non-inflammable and resistant to heat so it is used in coating, particularly in non-sticking frying pans.
The synthetic polymer which resembles natural rubber is
Solution
Solution
Ethylene-propylene rubber (EPR) is
The mass average molecular mass & number average molecular mass of a polymer are 40,000 and 30,000 respectively. The polydispersity index of polymer will be
Solution
Average number molecular weight \bar{M}_{n} = 30,000
Average mass molecular weight \bar{M}_{w} = 40,000
Polydispersity index (PDI) = \frac{\bar{M}_{w}}{\bar{M}_{n}} = \frac{40,000}{30,000} = 1.33
