Synthesis of Polydimethylsiloxane with hydrolysis and condensation methods using monomer of Dichlorodimethylsilane as vitreous humour substitute

Abstract

Vitreous humour is a fluid in the eye socket, that can be disturbed due to changes in its chemical or physical structure. Polydimethylsiloxane (PDMS) that also known as a silicone oil is a liquid that is commonly used as a substitute for vitreous humour in vitreoretinal surgery. PDMS can be synthesized from the monomer of Octamethylcyclotetrasiloxane (D4). However, in Indonesia, it is still difficult to obtain D4 monomer, so an alternative is needed. In this study, a synthesis of PDMS was carried out using the monomer precursor Dichlorodimethylsilane (DCMS) through a hydrolysis method under alkaline conditions using potassium hydroxide (KOH). Then the monomer obtained from the hydrolysis process was self-polymerized by aging to form a polymer gel. The concentration of KOH was varied at 0.5, 0.6 and 1 molar. The synthesized PDMS gel have viscosity values of 0.57, 1.53 and 4.49 Pa.s, density values of 0.986, 1.004, and 1.005 g/mL, refractive index in the range of 1.4001-1.4012, and surface tension in the range 19-21 mN/m. Those values of synthesized PDMS are similar to properties of commercial PDMS. We obtained that PDMS sample that synthesized using 1 M KOH shows the fastest polymerization time.