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How is sulfur chloride used in rubber vulcanization?

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A labeled diagram of the chlorine element from the periodic table shows its atomic number 17, symbol Cl, electron configuration, and atomic weight range. The box is shaded green to indicate chlorine is a halogen, with icons for orthorhombic crystal structure, gas state at room temperature, and strong acidity. A key explains the icons and colors used. — chlorine Properties of chlorine.

Sulfur chloride, specifically sulfur monochloride ( $S_{2} C l_{2}$ ), is used in the vulcanization of rubber through a process known as the "cold cure".12

Unlike standard vulcanization, which typically requires heating rubber with sulfur at high temperatures, the cold cure allows for the treatment of thin rubber products at ordinary temperatures. In this method, the rubber is exposed to a solution or vapors of sulfur monochloride. This chemical acts as a sulfurizing agent to create the necessary cross-links between polymer molecules, which improves the rubber's physical properties—such as its elasticity and resistance to temperature changes—without the need for the intense heat used in traditional curing processes.3214