氨丙基低聚硅倍半氧烷及其酰胺化产物的合成与表征

由3-氨基丙基三甲氧基硅烷（NH₂-propyl-silane）出发，在碱催化条件下采用水解缩合一锅法合成了笼形氨丙基硅倍半氧烷（NH₂-propyl-POSS）。红外光谱、核磁共振、电喷雾飞行质谱（ESI-TOF）表征结果表明，合成产物NH₂-propyl-POSS是不同大小笼形结构的混合物，其中T8、T9、T10笼形结构含量较高。由NH₂-propyl-POSS分别与乙酸和丙炔酸进行酰胺化反应，进一步合成了乙酰基丙基POSS（CH₃-CONH-POSS）和丙炔酰基丙基POSS（CH≡C—CONH-POSS），并通过红外光谱、氢谱、碳谱分析表征了其结构。X射线衍射分析结果表明，3种POSS均为非晶态结构。通过热重分析可知，NH₂-propyl-POSS具有较高的热稳定性。将NH₂-propyl-POSS用于提高环氧树脂（EP）的热稳定性，添加量为5 %（质量分数，下同）时，EP/NH₂-propyl-POSS共混物的玻璃化转变温度（T_g）提高至180.7 ℃，极限氧指数（LOI）为25.2 %。

Synthesis and characterization of aminopropyl oligomeric silsesquioxane and its amidation products

Caged aminopropylsilsesquioxane （NH₂-propyl-POSS） was synthesized through one-pot hydrolysis-condensation under alkali-catalyzed conditions using 3-aminopropyltrimethoxysilane as a raw material. The obtained products were characterized using infrared spectroscopy， nuclear magnetic resonance， and electrospray ionization-time of flight mass spectrometry. The results indicated that the synthesized NH₂-propyl-POSS was a cage-structured mixture with different sizes， and the contents of cage structured T8， T9 and T10 were relatively high. Acetylpropyl POSS and propynoyl POSS were further synthesized through the amidation of NH₂-propyl-POSS with acetic acid and propiolic acid， respectively， and their structures were characterized using infrared spectroscopy，¹H-NMR spectroscopy， and¹³C-NMR spectroscopy. X-ray diffraction analysis indicated that the three POSSs were all amorphous structures. According to the thermal decomposition characteristics obtained from thermogravimetric analysis， NH₂-propyl-POSS showed the highest thermal stability among the three POSSs. NH₂-propyl-POSS was used for epoxy resin （EP） to improve its thermal stability. The EP/NH₂-propyl-POSS blends exhibited a glass transition temperature of 180.7 oC and a limiting oxygen index of 25.2 vol% with the addition of 5 wt% POSS.