Effects of phenylethynylsilicon compounds on heat-curable silicone rubber. Part 2.–Phenylethynylvinyldiethoxysilane

The effects of (phenylethynyl)vinyldiethoxysilane (PVDES) as a crosslinker on heat-curable silicone rubber (HCSR) have been investigated. PVDES, which can, in certain specific amounts, improve the mechanical properties of vulcanizates, is a good crosslinker of silicone rubber. The tensile strength and the tear strength of some vulcanizates can reach 12.80 MPa and 56.4 kN m–1respectively, and the modulus of elasticity at 100% extension 4.10MPa. PVDES can also be used as a good hydrosilation curing retarder of silicone rubber. By adding 0.05 parts or more of PVDES to 100 parts of silicone gum the stocks could be stored at room temperature (20 ± 1 °C) for more than 50 days. The sol fractions and crosslinking density of the vulcanizates have been also measured.