High char yield novolac modified by Si-B-N-C precursor: Thermal stability and structural evolution. (March 2017)

• Record Type: Journal Article
• Authors: Wang, Yi; Chen, Lixin; Xu, Tingting; Yan, Yi; Gu, Junwei; Yun, Jin; Feng, Junjun
• Is Part Of: Polymer degradation and stability. Volume 137(2017.)
• Page Start: 184
• Page End: 196
• Publication Date: 2017-03
• Subjects: Ceramic precursor -- Modified novolac -- Thermal stability -- Structural evolution; Polymers -- Deterioration -- Periodicals; Stabilizing agents -- Periodicals; Polymères -- Dégradation -- Périodiques; Stabilisants -- Périodiques; 668.9
• DOI: 10.1016/j.polymdegradstab.2017.01.013
• Languages: English
• ISSNs: 0141-3910

Abstract

Abstract: 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 (B3 N3 ), elements of Si, B and N. The B3 N3 ring remains stable at 1400 °C. And fixed structure Si-Ox was formed during heat treatment. Moreover, CSEB also promote the graphitization.