| Summary: | 碩士 === 國立中興大學 === 化學工程學系所 === 94 === In the first part, three curing agents, o-DAH, p-DAH and DAHCY, were successfully synthesized, and their structures were confirmed by FTIR, Mass and NMR spectra. According to the solvent effect on the ratio of diastereomers of p-DAH, the carbocation addition mechanism was proposed. According to the Tg and activation energy of curing, no catalyst is required for the epoxy/o-DAH or p-DAH curing system. Judging from the Tg, Td, and char yield, the epoxy/DAHCY system has better thermal properties than those of the epoxy/ p-DAH or o-DAH system. In the DAHCY/epoxy system, the Tg value is in the order poly(DAHCY-CNE) > poly(DAHCY) >>poly(DAHCY-DGEBA).
In the second part, several new phosphorous-containing polymers with high Tg and Td were successfully synthesized by one-step approach via azomethine structure at room temperature. According to the experimental data, LiCl is crucial to the high molecular weight of new polymers, while p-TSA only has little effect on molecular weight in the presence of LiCl. The equilibrium of polyazomethine formation shifted to right after DOPO reacted with azomethine, resulting in the molecular weight of DDS-P2-I is higher than that of DDS-P2-II. Similar trend was observed for the 6FDAn-P2 system; that is, the molecular weight of 6FDAn-P2-I is higher than that of 6FDAn-P2-II. According to the molecular weight, NMR and FTIR characterization of DDM-P2, the reaction rate between aldehyde and amine is higher than that of aldehyde and DOPO. Besides, the reaction rate of nucleiphilic addition between DOPO and azomethine is higher than that of DOPO and formaldehyde.
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