Preparation,cure kinetics,and thermal properties of novel acetylene terminated silazanes

A new kind of acetylene terminated silazanes, N‐(3‐acetylenephenyl)‐diorganosilazanes (abbreviated as APSZs) with three kind of substituents, were synthesized by the aminolysis of dichlorosilane with 3‐aminophenylacetylene (3‐APA). Structure of APSZs was confirmed by Fourier transform infrared spectroscopy (FT‐IR) and nuclear magnetic resonance (NMR). Thermal behavior of the cured silazanes was determined by thermogravimetry analysis (TGA), revealing that cured silazanes exhibited high temperature resistance. The ceramic yields of APSZ‐Me₂, APSZ‐MeVi, and APSZ‐Ph₂ at 1000°C under nitrogen were 77.6, 81.9, and 68.7%, respectively. The peak separation of derivative thermogravimetric data was employed to evaluate the three major regions of the thermolysis, and the kinetic parameters of thermolysis were calculated by the method of Kissinger from dynamic thermogravimetric measurement in nitrogen atmosphere at several different heating rates. Influence of substituents on the thermal behavior of cured silazanes in each separated region was discussed. The results showed that the vinyl derivative exhibit higher thermal stability than methyl and phenyl derivatives due to the high decomposition activation energy and small pendant group. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012