文献类型：期刊文献

英文题名：Assessing pyrolysis behavior of silicon-containing arylacetylene resin via experiments and ReaxFF MD simulations

作者：Zheng, Fangjuan[1];Wan, Kun[1];Huang, Farong[1];Niu, Bo[1];Shi, Youan[2];Wei, Dong[2];Zhang, Yayun[1];Long, Donghui[1]

机构：[1]East China Univ Sci & Technol, Key Lab Specially Funct Mat & Related Technol, Minist Educ, Shanghai 200237, Peoples R China;[2]China Aerodynam Res & Dev Ctr, Mianyang 621000, Sichuan, Peoples R China

年份：2022

卷号：164

外文期刊名：JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS

收录：;EI(收录号：20221912082503);WOS:【SCI-EXPANDED(收录号:WOS:000804697300004)】；

基金：This work was financially supported by National Natural Science Foundation of China (No. 22008073, No. 21878091, No. 22078100, No. 52102098) , Shanghai Sailing Program (No. 20YF1410600) , Funda-mental Research Funds for the Central Universities, and Shanghai Talent Development Fund (No. 2021026) .

语种：英文

外文关键词：Silicon-containing arylacetylene resin; Pyrolysis; ReaxFF MD; Thermal stability; Mechanism

摘要：Silicon-containing arylacetylene resin (PSA), a thermosetting organic-inorganic hybrid resin of high heatresistance performs well in ablation process, whereas its pyrolysis behavior under high temperature has not been fully interpreted. Herein, the PSA pyrolysis process was in-depth investigated by experiments and ReaxFF molecular dynamics simulation (ReaxFF-MD). TG results show that the temperature of 5% weight loss (Td5) is above 600 degrees C, and the residue at 900 degrees C surpass 85%, demonstrating PSA has excellent heat resistance and thermal stability. The on-line FTIR and out-line gas quantify analysis reveals that H2 and CH4 are dominant gaseous products, which are also unveiled by ReaxFF-MD simulation. Molecular reaction tracking indicates PSA pyrolysis is initiated by the cleavage of skeleton in benzene ring, the cleavage of C-C bond and C-Si bond in main chain at elevated temperature. Hydrogen abstraction reactions are primary formation pathways of CH4 and H2, together with conquering high energy barriers. The activation energy of PSA pyrolysis in experiments is 155 kJ/ mol, agreeing well with that from ReaxFF MD simulations (144 kJ/mol), which further confirms the thermochemical stability of cured PSA that rich in highly crosslinked aromatic structure. Besides, the influence of silicon side-groups on PSA pyrolysis is screened by MD and results indicate that gases evolution depended largely on side-groups types and decreasing side phenyl groups in PSA is benefit for improving its thermal stability. This work deepens the understanding of PSA pyrolysis mechanism and provides theoretical guidance for improving its heat resistance.