Facile preparation of novel epoxy curing agents and their high‐performance thermosets |
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| Authors: | Ching Hsuan Lin Tsung Li Lin Sheng Lung Chang Shenghong A. Dai Ru Jen Cheng Kuen Yuan Hwang An Pang Tu Wen Chiung Su |
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| Affiliation: | 1. Department of Chemical Engineering, National Chung Hsing University, Taichung, Taiwan;2. Department of Chemistry, National Chung Hsing University, Taichung, Taiwan;3. Chang Chun Plastics Co., Ltd., ShinChu, Taiwan;4. Chemical Division, Chung‐Shan Institute of Science and Technology, Lungtan, Tauyuan, Taiwan |
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| Abstract: | Two flame‐retardant epoxy curing agents, 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐yl‐tris(4‐hydroxyphenyl)methane (1) and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐yl‐ (4‐aminophenyl)‐bis(4‐hydroxyphenyl)methane (2), were prepared by a facile, economic, one‐pot procedure. The structures of the curing agents were confirmed by IR, high‐resolution mass, 1‐D, and 2‐D NMR spectra. A reaction mechanism was proposed for the preparation, and the effect of electron withdrawing/donating effects on the stabilization of the carbocation was discussed. (1‐2) served as curing agents for diglycidyl ether of bisphenol A (DGEBA), dicyclopentadiene epoxy (HP‐7200), and cresol novolac epoxy (CNE). Properties such as glass transition temperature, coefficient of thermal expansion, thermal decomposition temperature, and flame retardancy of the resulting epoxy thermosets were evaluated. The resulting epoxy thermosets show high Tg, low thermal expansion, moderate thermostability, and excellent flame retardancy. The bulky biphenylene phosphinate pendant makes polymer chains difficult to rotate, explaining the high Tg and low thermal expansion characteristic. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7898–7912, 2008 |
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| Keywords: | curing agents curing of polymers flame‐retardance high performance polymers high Tg thermosets |
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