Synthesis and characterization of methacrylate phospho-silicate hybrid for thin film applications

Phosphorus containing methacrylate hybrids were synthesized from 2-(methacryloyloxy)ethyl phosphate (EGMP) and 3-[(methacryloyloxy)propyl] trimethoxysilane (MEMO) via dual-cure process involving sol-gel reaction and addition polymerization. The kinetics of the reactions was established using spectroscopic techniques. Photoacoustic Fourier transform infrared spectroscopy (PA-FTIR) and X-ray photoelectron spectroscopy (XPS) confirm the formation of Si-O-Si, P-O-P and Si-O-P linkages and simultaneous polymerization of methacrylate groups leading to a dense networked structure. The presence of silicate/phospho-silicate network in the hybrid enhances its thermal stability. Nanoindentation measurements on thin films show enhanced hardness and modulus with increasing silicate network. Topographic and conductivity images obtained using micro-thermal analysis (μTA) reveal a dense, homogenous and defect-free thin film formed on metallic substrate with a Tg of 93 °C.