Question

Vulcanised rubber resists:
This question has multiple correct options
A. wear and tear due to friction
B. cryogenic temperature
C. high temperature
D. action of acids

Answer 1

Vulcanisation is a process of making hard rubber. It is performed by treating rubber with sulfur. The sulfur atom acts as the linker between the chains of monomer units.

Complete step by step answer: The vulcanisation method is used for hardening of polymers. The sulfur mediated vulcanization is the most common. The sulfur linkages add several features to the polymers formed. Let us consider the features one by one and check whether they apply or not to vulcanised rubber.
Wear and tear due to friction: Friction causes excessive heat generation between the surfaces. Due to this fire is produced and this leads to wear and tear of the surface. Vulcanisation makes the surface of rubber more elastic and resilient. It increases the tensile strength, hardness and the viscosity. So vulcanised rubber can resist wear and tear due to friction.
Cryogenic temperature: Cryogenic temperature is the temperature range of $- 150^\circ C$ to absolute zero. The property of elasticity at this temperature generally is lost and the substance freezes. For vulcanized rubber also the property of elasticity does not work in this temperature range and it is found to freeze at$- 50^\circ C$. So, vulcanised rubber does not resist cryogenic temperature.
High temperature: Vulcanised rubber can only resist the temperature of$140 - 160^\circ C$. This is the temperature at which they are formed. Beyond that temperature the rubber degrades and so they do not resist high temperature.
Action of acid: It was found that vulcanised rubber is not affected by acid rains. Acid rains are the combination of several acids like sulfuric acid, sulfurous acid, nitric acid which are formed by combination of water and $S{O_2}$ or $N{O_2}$. So vulcanised rubber can resist the action of acid.
So, the correct answers are “Option A and D”.

Note: Vulcanisation processes enhance the rigidity and durability of substances. They are normally done by inserting the rubber with sulfur or metal oxides. Silicone rubber is also a vulcanised rubber where metal oxides are incorporated with neoprene. This type of insertion gives rise to a complex cross linked polymer chain.