Study on the optimization of cationic ring opening polymerization of silicone-based epoxy monomers for holographic photopolymers

Abstract

This study examined the optimum compositions of binder, photo-acid generator (PAG) and sensitizer for the cationic ring opening polymerization of 1,3-bis[2-(3-{7-oxabicyclo-[4.1.0]heptyl})]-tetramethyldisiloxane in the presence of polydimethylsiloxane with four epoxide moieties as a co-monomer. When diffractive efficiency (DE) values were compared quantitatively to analyze the effect of the binder on holographic photopolymerization, DE was affected by the viscosity of the binders and miscibility with the monomer mixture. Extremely low DE values were observed when the immiscible dimethyl silicone was used as a binder. Therefore, methylphenyl silicone, which is miscible with the monomer mixture, was used as the binder for further studies. The optimal conditions were a binder viscosity between 250 to 390 cP, and contents of the binder, PAG, and sensitizer were 75-125 wt%, > 6 wt% and 0.05 wt% to the total monomer mixture, respectively.

A Review of the Optimisation of Photopolymer Materials for Holographic Data Storage

“…In 2009, Kim and Chung [73] optimised a photopolymer system made from complex compositions of binder, photoacid generator (PAG), and sensitiser involving the cationic ring-opening polymerization of 1,3-bis[2-(3-7-oxabicyclo-[4.1.0]heptyl)]-tetramethyldisiloxane in the presence of polydimethylsiloxane, with four epoxide moieties as a comonomer. It was found that when diffractive efficiency values were compared quantitatively, in order to analyse the effect of the binder on holographic photopolymerisation, the diffractive efficiency was affected by the viscosity of the mixture.…”