Question

The compound of sulphur used as a solvent in rubber industry is
(a) ${\text{S}}{{\text{O}}_{\text{2}}}\left( {{\text{OH}}} \right){\text{Cl}}$
(b) ${\text{S}}{{\text{O}}_{\text{2}}}$
(c) ${\text{S}}{{\text{O}}_{\text{3}}}$
(d) ${{\text{S}}_{\text{2}}}{\text{C}}{{\text{l}}_{\text{2}}}$

Answer 1

Hint: Sulphur vulcanize unsaturated rubbing polymers (double bonded polymer chains) such as natural rubber, styrene butadiene rubber, nitrile butadiene rubber, etc.

Complete step by step answer:
Sulphur vulcanization or sulphur vulcanization is a chemical process to convert natural rubber or related polymers into more durable materials by heating them with sulfur or another equivalent curative or accelerator. The most common vulcanization agent is sulfur. It forms bridges between different polymer molecules when heated with rubber.
${{\text{S}}_2}{\text{C}}{{\text{l}}_2}$ is used as a solvent in the rubber industry.

So, the correct answer is Option d.

Additional information:
Vulcanized rubber: Natural rubber is soft and tacky and becomes even more at high temperatures and brittle at low temperatures. Therefore, rubber is generally used in the temperature range 283-335K where its elasticity is maintained. It possesses low tensile strength, a large water absorption capacity and low resistance to abrasion. It is also not resistant to the action of organic solvents and is also easily attacked by oxidising agents. These properties can be improved by a chemical process known as vulcanization.
It consists of heating raw rubber with sulphur at 373-415 K. Since this process is slow, additives like zinc oxide, etc. are used to accelerate the rate of vulcanization. The obtained vulcanized rubber possesses low water absorption tendency, excellent elasticity and is resistant to the action of organic solvents and oxidising agents. During vulcanization, sulphur bridges or cross-links between polymer chains are introduced either at their reactive allylic positions or at the sites of the double bonds.
These cross links make rubber hard and stronger and remove the tackiness of natural rubber since the individual chains can no longer slip over the other but are instead locked together in a giant size molecule . The extent of hardness or toughness depends on the amount of sulphur added.
About 5% sulphur is used for making tyre rubber, 20 - 25% S for making ebonite and 30% S for making batter case rubbers .The process of vulcanization was discovered by Charles Goodyear in 1839.

Note: Mineral sulphur is a widely used component in the vulcanization process to form cross-links between rubber chains. During compounding, high elastic state of sulfur at temperatures between ${\text{4}}0{\text{ }}^\circ {\text{C}}$ and $70{\text{ }}^\circ {\text{C}}$ promotes elongation of its particles and, next, breaks these thin and weak needles into pieces.