High char yield novolac modified by Si-B-N-C precursor: Thermal stability and structural evolution
作者:Yi Wang, Lixin Chen*, Tingting Xu, Yi Yan, Junwei Gu, Jin Yun, Junjun Feng
关键字:Ceramic precursor,Modified novolac,Thermal stability,Structural evolution
论文来源:期刊
具体来源:Polymer Degradation and Stability,2017,137,184-196.
发表时间:2017年
In this contribution, novolac modified by CSEB ceramic precursor (B,B,B-tris[(chlorodimethylsilyl)-ethane]borazine, CSEB) was synthesized successfully. The corresponding molecular structure, chemical state and thermal property were characterized by FT-IR, Raman spectra, XPS, NMR and TGA. Meanwhile, DTA/TG/MS test was also performed to track the weight loss and gas evolution of modified novolac during the thermal degradation. CSEB could obviously improve the thermal decomposition temperature and the char yield of novolac. The maximum decomposition rate temperature is increased up to 575.2 C. The char yield is increased to 75.5% at 800 C, 72.6% at 1000 C and 68.7% at 1200 C, respectively. The improvement of the thermal stability of modified novolac could be mainly attributed to the incorporation of six-membered borazine ring (B3N3), elements of Si, B and N. The B3N3 ring remains stable at 1400 C. And fixed structure Si-Ox was formed during heat treatment. Moreover, CSEB also promote the graphitization.