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161.
Md. Chanmiya Sheikh Shunsuke Takagi Asako Ogasawara Masayuki Ohira Ryuta Miyatake Hitoshi Abe Toshiaki Yoshimura Hiroyuki Morita 《Tetrahedron》2010,66(12):2132-3975
The reaction of N-(3-phenylpropionyloxy)phthalimide (1a) and N-tosyloxy (5a,b) derivatives with nucleophiles was examined and found to give the products via Lossen-type rearrangement. In order to obtain the scope of this reaction mechanism, further studies the reaction of several N-sulfonyloxyimide derivatives with various nucleophiles under similar conditions were carried out and found to afford the corresponding same types of products in high yields. 相似文献
162.
Chanchira JubsilpTsutomu Takeichi Sarawut Rimdusit 《Polymer Degradation and Stability》2011,96(6):1047-1053
A novel bisphenol-A-aniline type polybenzoxazine (PBA-a) modified with dianhydride was successfully prepared by reacting bisphenol-A-aniline based benzoxazine (BA-a) resin with 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) in 1-methyl-2-pyrrolidone (NMP) solvent. The miscible monomer mixture was easily transformed into transparent PBA-a/BTDA copolymers by thermal cure. Fourier-transform infrared spectroscopy reveals the formation of ester linkage which is a covalent interaction between hydroxyl group of the PBA-a and the carbonyl group in the dianhydride. The PBA-a/BTDA copolymers show only one glass transition temperature (Tg) with the value as high as 263 °C at BA-a:BTDA = 1.5:1 mol ratio. The value is remarkably higher than that of the unmodified PBA-a, i.e. 160 °C. In addition, the resulting PBA-a/BTDA copolymers display relatively high degradation temperature up to 364 °C and substantial enhancement in char yield with a value of up to 61% by weight. Moreover, flexibility of the PBA-a/BTDA copolymer samples is also significantly enhanced compared to the unmodified PBA-a. The obtained copolymer demonstrates high potential for those applications that require high thermal and mechanical properties with fire resistant characteristics. 相似文献