聚二甲基硅炔树脂的热分解与介电分析

Thermal Degradation and Dielectric Studies of Polydimethyl Silicon Alkyne Resin

采用镁条、溴乙烷、苯乙炔为原料,通过格氏试剂反应法与二甲基二氯硅烷反应,成功制备了二甲基二苯乙炔基硅烷(DDPES),采用红外(FT-IR),核磁共振(1H-NMR,、13C-NMR、29Si-NMR)对其结构进行表征分析,并通过热聚合法制备聚二甲基二苯乙炔基硅烷(PDDPES)树脂。借助TG-DTG技术分析了PDDPES树脂的热性能。采用6种动力学方法分别为:Kissinger、FWO、Coats-Redfern、ABSW、KAS和Tang法,研究了PDDPES树脂的热分解行为,并测试了该树脂的介电性能。实验结果表明,PDDPES树脂的平均热分解活化能为166.80 k J/mol,热分解过程遵循随机成核机理和随后生长机理,树脂在2~18 GHz频率下的介电常数实部为2.45~2.85,介电常数虚部为0.05~0.30;损耗角正切值为0~0.11,因此,该树脂是一种新颖的透波材料用树脂基体。

Dimethyl(diphenylethynyl)silane(DDPES)was synthesized via grignard reaction of dimethyldichlorosilane and phenylacetylene in the presence of magnesium and ethyl bromide.The chemical structure was characterized by fourier transform infrared spectroscopy(FT-IR)and nuclear magnetic resonance spectroscopy(1 H-NMR,13 C-NMR,and29 Si-NMR).The polydimethyl(diphenylethynyl)silane(PDDPES)resin was also synthesized by thermal polymerization.The thermal decomposition behavior was analyzed by TG and DTG and the corresponding kinetic parameters and curing mechanism were discussed by six well-known kinetic methods,of Kissinger,FWO,Coast-Redfern,ABSW,KAS and Tang methods;and the dielectric property of PDDPES was also tested.Results showed that the resin’s average thermal decomposition activation energy was 166.80 k J/mol.The thermal decomposition process followed the random nucleation and subsequent growth mechanism.The dielectric real part of the resin was 2.45~2.85 and the imaginary part of the dielectric constant was 0.05~0.30 in the frequency of 2~18 GHz.The dielectric loss tangent value range was 0~0.11.So the wave-transparent resin matrix was novel.