CROSSLINKED ORGANIC–INORGANIC POLY(IONIC LIQUID) HYBRID FILMS PREPARED BY COMBINING SOL-GEL AND POLYMERIZATION PROCESSES
HSIAO-YUAN MA
Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan
CHIEN-HSIN YANG *
Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan
*Author to whom correspondence should be addressed.
Abstract
Polymerizable organic-inorganic TiO2 hybrid sols (TiO2 hybrid sol) were first synthesized by the sol-gel method. This TiO2 hybrid sol mixed into vinylimidazolium-based ionic liquids and then performed free-radical copolymerization to obtain an inorganic-organic poly(ionic liquid) (PIL) hybrid. Results show that the TiO2 hybrid sol was successfully incorporated into the networks of PIL polymers. The conductivity of the PIL hybrids increases with increasing the content of TiO2 hybrid sol to attain the highest value of 1.04×10-4.5 Scm-1. The thermal stability of the resulting hybrids increases with the content of inorganic components. In thermogravimetric analysis (TGA), the integral procedure decomposition temperature (IPDT) of Doyle’s method was used to correlate the volatile parts of polymeric materials and used for estimating the inherent thermal stability of polymeric materials. The IPDT of pure PILs was 416°C and the IPDTs of hybrids were higher than that of pure PILs. The incorporation of inorganic components in PIL at a level of 3.89 wt% achieved the electrical conductivity of 10-4.5 Scm-1 as compared 10-4.8 Scm-1 of pure PILs.
Keywords: Poly(ionic liquids) (PILs), sol gel method, organic/inorganic hybrid, electrical conductivity, thermal stability