sulfidecrosslinked

Sulfide crosslinking is a chemical process used to create covalent bonds between polymer chains using sulfur atoms. This technique is widely employed in the rubber industry, particularly for the vulcanization of natural and synthetic rubbers. During vulcanization, sulfur atoms are introduced into the polymer matrix, and under heat and pressure, they form sulfur bridges, typically S-S or polysulfide linkages (S_x), connecting individual polymer strands. This crosslinking process transforms the soft, pliable raw rubber into a more robust and elastic material with improved tensile strength, abrasion resistance, and resistance to heat and solvents.

The degree and type of sulfur crosslinking can be controlled by varying the amount of sulfur and other additives like accelerators and activators. Shorter polysulfide crosslinks or disulfide crosslinks generally impart higher resilience and lower hysteresis, while longer polysulfide crosslinks can enhance flexibility and low-temperature performance. Uncontrolled or excessive sulfide crosslinking can lead to embrittlement and a loss of elasticity. The stability of sulfide crosslinks can be a limiting factor in high-temperature applications, as these bonds can break and reform, leading to degradation over time. Despite this, sulfide crosslinking remains a cornerstone of elastomer technology due to its cost-effectiveness and versatility.