No abstract

A composite structure based on silylated MCM-41 and Poly (vinyl acetate) (PVAc) was synthesized via solution intercalation. Poly (vinyl acetate)-silylated Si-MCM-41 composite were characterized by XRD, FTIR spectroscopy and13C CP/MAS NMR in order to determine the compatibility between PVAc and the silicate host. XRD study reveals that the framework of silylated Si-MCM-41 was not altered upon incorporation of PVAc. FTIR study showed that characteristic peak assigned to carbonyl group in PVAc was observed around 1741.6 cm-1for all the composites indicating the presence of PVAc in the silylated Si-MCM-41.13C CP/MAS NMR showed the increase of line width of the peak assigned to C=O carbonyl group indicating the increase in randomness of polymer chains in confined space. The shifting of the C=O carbonyl groups is a sign of the change in chemical environment of the carbonyl owing to the interaction of PVAc with the silica matrix of silylated Si-MCM-41.

Free standing solid polymer electrolyte films based on poly (methyl methacrylate) PMMA and Poly (vinyl chloride), PVC can be obtained when blend with 10% and 50% of 50% epoxidised natural rubber, ENR 50 respectively. This work conducted impedance spectroscopy studies on PVC / ENR 50 and PMMA / ENR 50 based electrolyte systems when doped with lithium triflate, LiCF 3 SO 3 salt. PVC / ENR 50 / LiCF 3 SO 3 exhibited higher bulk resistance, R b and lower conductivity values than PMMA / ENR 50 based electrolytes. The highest conductivity achieved for PMMA / ENR 50 blend is 5.09 x 10 -5 S/cm and 3.64 x 10 -8 S/cm for PVC / ENR 50 blend when doped with 60% of LiCF 3 SO 3 salt. The plots of logarithm of ionic conductivity against the reciprocal of absolute temperature revealed that the ionic conduction in PVC / ENR 50 / LiCF 3 SO 3 electrolyte follows the WLF theory and PMMA / ENR 50 / LiCF 3 SO 3 electrolyte obeyed the Arrhenius behavior.