- 作者: Chang-Chung Yang, Wen-Chang Chen, Li-Mei Chen, and Cho-Jen Wang
- 中文摘要: The structures and properties of three poly(silsesquioxane) (POSS) films were studied, including hydrogen silsesquioxane (HSQ), methyl silsesquioxane (MSQ), and hybrido-organo siloxane polymer (HOSP). The cage structures of the POSS films were transformed into network structures by means of thermal curing. The order of the ratios of network/cage transformation after thermal curing was HSQ > MSQ > HOSP. This was the same as the order of the refractive indices of the studied POSS films because of the variation of the molar volume due to the network/ cage ratio. The structural conversion of the MSQ film was studied at four different temperatures of 200, 250, 300, and 350C under a time range of 0 to 60 minutes. The experimental results show that the structural conversion could be explained based on two-stage zero order kinetics. The rate constant for the first stage was one or two orders of magnitude greater than that for the second stage. The activation energy and frequency factor of network/cage transformation were 0.38 eV and 1.21 ? 10 2 s .1 for the first stage while those for the second stage were 0.14 eV and 8.8 ?10 .3 s .1 , respectively. The smaller frequency factor of the second stage compared to that of the first stage probably occurred because the network structure of the second stage limited the structural transformation. These results suggest that the structure and properties of the POSS film depend strongly on the conditions of thermal curing.
- 英文摘要: --
- 中文關鍵字: poly(silsesquioxane), curing, cage, network, two-stage kinetics
- 英文關鍵字: --