聚十二烷基三苯乙炔基硅烷树脂的制备与热性能

Preparation and Thermal Perperties of Polydodecyl-(triphenylethynyl) silane

以镁条、溴乙烷、苯乙炔和十二烷基三氯硅烷为原料,通过Grignard反应制得十二烷基三苯乙炔基硅烷单体(DTPES)。采用傅里叶变换红外光谱(FTIR)和核磁共振波谱(~1HNMR、^(13)CNMR和^(29)Si NMR)对DTPES结构进行了表征;利用差示扫描量热法(DSC)确定了DTPES的最佳固化工艺。通过热聚合法制得聚十二烷基三苯乙炔基硅烷树脂(PDTPES),利用TG-DTG分析了PDTPES树脂的热稳定性,并采用6种方法(Kissinger、Ozawa、Achar、Cosat-Redfern、Friedman和Vyazonvkin-Weight法)对树脂的热分解行为进行了探究。结果表明,升温速率为10℃/min时,PDTPES树脂质量损失5%的温度(T_(d5))为440℃,800℃下残炭率为48.1%。动力学分析显示,不同分析方法下,PDTPES树脂的热分解活化能(E_a)分别为182.76、181.53、179.48、179.45、187.53和178.33 kJ/mol,指前因子(A)分别为1.05×10^(12)、3.40×10^(10)、3.79×10^(12)、1.88×10^(11)、5.73×10^(11)和1.52×10^(11)s^(–1),并求得热分解动力学方程。

Dodecyltris(2-phenylethynyl)silane(DTPES)was synthesized via Grignard reaction of dodecyl trichlorosilane and phenyl acetylene in the presence of magnesium and ethyl bromide.Its chemical structure was characterized by Fourier transform infrared spectroscopy(FTIR)and nuclear magnetic resonance spectroscopy(1HNMR,13CNMR,29Si NMR).Its curing process was obtained by differential scanning calorimetry(DSC).Subsequently,polydodecyl(triphenylethynyl)silane(PDTPES)was synthesized by thermal polymerization of DTPES monomer.The thermal decomposition behavior was analyzed by TG and DTG and the corresponding kinetics parameters and thermal decomposition characteristics were discussed by six kinetics methods,i.e.,Kissinger,Ozawa,Achar,Coast-Redfern,Friedman and Vyazonvkin-Weight methods.The results showed that the decomposition temperature at 5%weight loss(Td5)of the resin was440℃and the char yield was 48.1%at 800℃under a heating rate of 10℃/min.The activation energy Ea and the pre-exponential factor A were 182.76,181.53,179.48,179.45,187.53 and 178.33 kJ/mol,and1.05×1012,3.40×1010,3.79×1012,1.88×1011,5.73×1011 and 1.52×1011 s–1,respectively,by the above methods.The thermal decomposition kinetics equation was also proposed.