PVMS serves as a critical reactive modifier in silicone rubber compounding. Unlike Vinyl Terminated Fluids, which react only at the chain ends, PVMS offers pendant vinyl groups along its backbone. When added to a standard addition-cure system (vinyl-terminated PDMS with Si-H crosslinker), the pendant vinyl sites provide additional, internal crosslinking points.

This architecture allows compounders to precisely engineer material properties:

Increased Crosslink Density: Enhances tear strength and tensile modulus without excessively sacrificing elongation.

Reduced Compression Set: Improves the elastomer's ability to recover after prolonged deformation, critical for static seals and gaskets.

Customizable Hardness: Enables fine-tuning of durometer in the Shore A 20-80 range.

This makes PVMS indispensable for producing high-consistency rubber (HCR) for automotive ignition cables and custom-molded seals with demanding specifications.