Morphology and thermomechanical properties of organic-inorganic hybrid composites involving epoxy resin and an incompletely condensed polyhedral oligomeric silsesquioxane
Morphology and thermomechanical properties of organic-inorganic hybrid composites involving epoxy resin and an incompletely condensed polyhedral oligomeric silsesquioxane
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DOI：
10.1021/ma0504318
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发表时间：
2005-06-14
期刊：
影响因子：
5.5
通讯作者：
Nie, KM
中科院分区：
文献类型：
--
作者：
Liu, HZ;Zheng, SX;Nie, KM
用不完全缩合的多面体低聚倍半硅氧烷（POSS）改性环氧树脂，并将苯基三硅醇POSS [Ph 7Si 7 O 9（OH）（3），POSS-triol]引入到环氧树脂网络中，POSS含量达到30wt%。以POSS-三醇和环氧单体的均相溶液为原料，在POSS-三醇存在下，通过环氧单体的原位聚合制备了有机-无机杂化复合材料。以金属络合物三乙酰丙酮铝（[Al]）为催化剂，POSS三醇与双酚A二缩水甘油醚（DGEBA）反应，制备了环氧树脂/POSS三醇纳米复合材料。另外，发生了由聚合引起的相分离，并且获得了精细的相分离结构，其中球形POSS-三醇颗粒（直径0.3-0.5 μ m）分散在连续的环氧树脂基体中。不同形态结构的混杂复合材料表现出不同的热机械性能。相分离的复合材料具有较高的玻璃化转变温度（T-g的）比纳米复合材料，而纳米复合材料显示出较高的储能模量的玻璃态的光动态力学分析（DMA）。在热重分析方面，纳米复合材料显示出较高的初始热分解温度（T-d's）。热机械性能的改善归因于POSS部分的纳米分散。
Epoxy was modified by an incompletely condensed polyhedral oligonieric silsesquioxane (POSS), and the phenyltrisilanol POSS [Ph7Si7O9(OH)(3), POSS-triol] was incorporated into the epoxy networks with the content of POSS up to 30 wt %. The organic-inorganic hybrid composites were prepared via in situ polymerization of epoxy monomers in the presence of POSS-triol, which started from the homogeneous solutions of POSS-triol and epoxy monomers. The nanocomposites of epoxy with POSS-triol can be prepared with the metal complex, aluminum triacetylacetonate ([Al]) being used as the catalyst for the reaction between POSS-triol and diglycidyl ether of bisphenol A (DGEBA). Otherwise, the phase separation induced by polymerization occurred, and the fine phase-separated structures were obtained, in which the spherical POSS-triol particles (0.3-0.5 mu m in diameter) were dispersed in the continuous epoxy matrices. The hybrid composites with the different morphological structures displayed quite different thermomechanical properties. The phase-separated composites possessed the higher glass transition temperatures (T-g's) than the nanocomposites while the nanocomposites displayed the higher storage modulus of glassy state in light of dynamic mechanical analysis (DMA). In terms of therniogravimetric analysis, the nanocomposites displayed the higher initial thermal decomposition temperatures (T-d's). The improvement in thermomechanical properties has been ascribed to the nanodispersion of POSS moieties.