Preparation of copolymeric gels composed of polydimethylsiloxane and polyethylene oxide network chains and their specific characteristics

Copolymeric networks composed of two chemically different network chains, polydimethylsiloxane (PDMS) and polyethylene oxide (PEO), are prepared by the two synthetic methods: (1) Vinyl-terminated PDMS and PEO are end-linked with the multi-functional silane compounds; (2) Vinyl-terminated PEO and silyl-terminated PDMS are end-linked with each other. The compositions in the resulting two-component networks are determined by two independent methods: H-1 NMR analysis of the extracted unreacted materials and thermogravimetric analysis of the network samples. The appearances of the copolymeric networks are transparent. The differential scanning calorimetry and dynamic mechanical analysis show that the copolymeric networks have the microphase separated structures composed of PDMS and PEO phases. Swelling experiments in various solvents clearly indicates the amphiphilic character of the copolymeric networks. The Li-doped copolymeric networks, which are obtained by immersing the gels in LiClO4, exhibit conductivity of the order of 10(-6) S cm(-1) at room temperature. The temperature dependence of the conductivity obeys the William-Ferry-Landel equation based on the free volume theory.