Products and kinetics of the cationic ring-opening polymerization of 3-glycidoxypropylmethyldimethoxysilane by lithium perchlorate

The cationic ring-opening polymerization (ROP) of 3-glycidoxypropylmethyldimethoxysilane (GMDM) induced by anhydrous lithium perchlorate (LiClO4) was investigated along with the sol-gel reaction of the methoxy groups. The polymer constructed using poly(ethylene oxide) (PEO) prepared from the ROP of epoxy groups and a subsequent sol-gel reaction of the methoxy groups was found to be a free-standing and transparent solid. The polymer exhibited ionic conductivity explained by the Vogel-Tamman-Fulcher (VTF) equation. Study of the PEO polymerization process and analysis of the byproducts were performed. A study of the reaction kinetics estimated the activation energy of ROP to be 77.9 +/- 2.0 kJ mol(-1). In addition to the linear PEO structure, cyclic products with a crown ether structure were also produced. It was also determined that the ROP and sol-gel reactions of the methoxy groups proceeded independently. The color change obtained following the reaction was explained by considering the Rayleigh scattering of visible light from the nanoparticles constructed from the ring-opened polymerized products of the epoxy groups.