Synthesis of low viscosity of polymethylhydrosiloxane using monomer of dichloromethylsilane

Abstract

Polydimethylsiloxane (PDMS) is a vitreous humour substitutes in vitreoretinal surgery to treat retinal detachment. PDMS was synthesized from the monomer octamethylcyclotetrasiloxane (D4). However, D4 is difficult to obtain in Indonesia. So, we need an alternative to replace PDMS. One type of siloxane polymer that can be a potential substitute as PDMS is polymethylhydrosiloxane (PMHS). In this study, PMHS was obtained from the hydrolysis-condensation process of dichloromethylsilane (DCHS). The hydrolysis process produces monomer that is ready for the condensation process to produce PMHS. Monomer and polymer samples were characterized to determine viscosity, surface tension, refractive index, and functional groups. The monomer sample has a viscosity in the range of 28.7-36.4 mPa.s. The surface tension and refractive index are in the range of 17-18 mN/m and 1.3954-1.3958. The polymer sample has a viscosity of 560-1130 mPa.s with a surface tension of 19 mN/m and a refractive index in the range of 1.3966-1.3970. From the FTIR measurements, all major functional groups in both monomers and polymers of PDMS were observed with the addition of Si-H functional groups which characterize PMHS. These results indicate that PMHS with low viscosity has been successfully obtained by hydrolysis- condensation method of DCHS.