Organocyclophosphazenes / Silica Hybrid Materials I. Synthesis and characterization of siloxane monomers and of cyclophosphazene / SiO2 composites

摘要

In the context of developing new phosphazene/silica hybrids for preparation of thermally resistant membranes for gas separation processes, two cyclophosphazenes/organosiloxane monomers (1 and 2, scheme 1) were synthesized via aminolysis of hexachlorocvclotriphosphazene (N3P3Cl6) with the monoamine functional trialkoxysilanes: 3-(triethoxysilyl)-propylamine (H2N-(CH2)3-Si(OC2H5)3) or 3-(trimethoxysilyl)-propylamine (H2N-(CH3)3-Si(OCH3)3) respectively, as new starting compounds for cyclophosphazene/SiO composites prepared by the sol-gel process. The siloxane monomers, N3P3Cl3[N(CH2)3 Si(OCH3)3], (1) and N3P3Cl4[N(CH2)3 Si(OCH2CH3)3], (2), as well as the corresponding composites {N3P3Cl3[N(CH2)3]3}_y-(SiO2)_(41y) (1') and {N3P3Cl4[N(CH2)3]3}_y-(SiO2)_(80y) (2') issues from the sol-gel process, have been characterized by infrared spectroscopy and elemental analysis, TG-DTA-DSC coupled thermal analyses, as well as by XPS, XRD, and SEM-EDAX investigations.