Step 1: Understanding the Concept:
Raw natural rubber is soft, sticky, and has low tensile strength. Vulcanization is a chemical process used to improve these physical properties by heating the rubber with a specific cross-linking agent.
Step 2: Key Formula or Approach:
The process involves creating chemical "bridges" between the long polymer chains of isoprene.
Step 3: Detailed Explanation:
In vulcanization, raw rubber is heated with Sulphur (typically 3–5%) and appropriate additives. The sulphur atoms form cross-links (disulphide bonds) between the polyisoprene chains. This makes the rubber harder, more elastic, and less sensitive to temperature changes.
Step 4: Final Answer:
The chemical added during vulcanization is Sulphur.