A Homogenous, Photocrosslinkable Poly(dimethylsiloxane‐co‐methylvinylsiloxane) Solution in an Acrylate Monomer

In this study, a simple photocuring method is proposed for preparing PDMS elastomers using a homogenous poly(dimethylsiloxane) (PDMS) solution in tert‐butyl acrylate (tBA) as an alternative way of mechanically blending two kinds of PDMS respectively containing vinyl and hydridosilyl groups over a platinum catalyst. Poly(dimethylsiloxane‐co‐methylvinylsiloxane) (PDMSc) with 30 mol% of vinyl moieties is synthesized. The functionalized PDMS is estimated to be soluble in tBA from theoretical calculations of solubility parameters of PDMS and several liquid monomers. The PDMS solution is satisfactorily photocured under a conventional photoinitiator. Initial modulus and strain of the photocured films increase from 144 to 552 MPa and decrease from 3.96 to 1.84, respectively, as the tBA content rises from 5 to 30 wt%. They are extremely transparent in a visible region (T > 94%) regardless of the amount of tBA. The unreacted vinyl groups in PDMSc are inter‐ or intrareacted near 200 °C and γ‐hydrogen transfer reactions from the tert‐butyl groups in poly(tert‐butyl acrylate) occur over 250 °C. One of the photocrosslinked films exhibits outstanding performance as an electroactive polymer in application. In essence, this study will initiate a new methodological research into provision of PDMS elastomers using an easily formulated photocrosslinkable PDMS solution. A homogenous, photocrosslinkable poly(dimethylsiloxane) (PDMS) solution in tert‐butyl acrylate (tBA) is developed. PDMS is highly functionalized to be readily crosslinked upon UV‐irradiation. tBA acts as a crosslinker as well as a solvent suitable for the PDMS. Photocured films can be successfully obtained from the PDMS solution over a simple fabrication process. Their physical properties meet expectations of using as an elastomer material.