Spectroscopic characterization of GPTMS/DETA and GPTMS/EDA hybrid polymers

Silica/epoxy hybrid polymers were synthesized from 3-glycidoxypropyltrimethoxysilane (GPTMS) by hydrolysis of the silane functional groups at a range of pHs and water contents of the reaction mixtures, followed by crosslinking by ring opening of the epoxy groups using diethylenetriamine (DETA) or ethylenediamine (EDA). The GPTMS/DETA and GPTMS/EDA hybrid polymers were formed to an extent determined by the mole ratio of active hydrogens from the diamine to epoxy rings (R_H). Structural characterization of the hybrid polymers was performed using Scanning Electron Microscopy (SEM), and Raman, and ¹³C and ²⁹Si Solid-State Nuclear Magnetic Resonance (NMR) spectroscopies. The results showed that extensive crosslinking occurred for GPTMS/DETA and GPTMS/EDA rigid, homogeneous hybrids with R_H = 1, particularly at pH 10.