Shuyan Yu, H. Seino, M. Ueda
Jan 30, 1999
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0
Influential Citations
6
Citations
Journal
Macromolecules
Abstract
An ordered (−ccfebaddabef−) poly(amide−acylhydrazide−amide) was prepared by the direct polycondensation of 5-(3-carboxypropyl)-2-isopropoxybenzoic acid (XabX), bis(4-nitrophenyl) isophthalate (XccX), piperazine (YddY), and 4-aminobenzohydrazide (YefY), using the condensing agent diphenyl(2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate (1). The polymerization was carried out by mixing the dicarboxylic acid, diester, condensing agent 1, and triethylamine (TEA) in N-methyl-2-pyrrolidinone (NMP) for 3 h at room temperature, followed by adding piperazine and aminobenzohydrazide at −15 °C. The mixture was stirred at −15 °C for 2 h, room temperature for 24 h, and 70 °C for 4 d in the presence of 1-hydroxybenzotriazole (HOBt). The resulting polymer gave an inherent viscosity of 0.20 dL/g in NMP, measured at a concentration of 0.5 g/dL at 30 °C. The feasibility of the formation of the ordered polymer from three nonsymmetric monomers was demonstrated by studying the model reactions in detail. Furthermore, the authe...