VDT -163

Vinylmethylsiloxane - dimethylsiloxane copolymer, trimethylsiloxy terminated. The vinylmethylsiloxane copolymers are mostly employed in peroxide activated cure systems which involve peroxide induced free radical coupling between vinyl and methyl groups. VDT -163 with extremely high molecular weights is the typical base stock for activated cure silicone elastomers. The base stocks are commonly referred to as gums which have molecular weights from 500,000 to 900,000 with viscosities exceeding 2,000,000 cSt. In this copolymer the use of peroxide activated cure chemistry for vinylmethylsiloxanes is well established for gum rubber stocks, its use is growing in new applications that are comparable to some peroxide cure acrylic systems. Its relatively low viscosity is employed as grafting additives to EPDM elastomers in the wire and cable industry to improve electrical properties. It is also used in sealants and encapsulants applications.