標題: | Sequential distribution of copolyesters containing the phosphorus linking pendant groups characterized by H-1-NMR |
作者: | Chang, SJ Chang, FC 應用化學系 Department of Applied Chemistry |
關鍵字: | H-1-nmr;phosphorus-containing copolyester;sequential distribution |
公開日期: | 1-六月-1998 |
摘要: | A series of phosphorus-containing copolyesters were synthesized by polycondensation of terephthalic acid (TPA), ethylene glycol (EG) and 9,10-dihydro-10-[2, 3-di(hydroxycarbonyl)propyl]-9-oxa-10-phosphaphenanthrene-10 -oxide (DDP). Chemical structures of these phosphorus-containing copolyesters were characterized by H-1-n.m.r.. Experimental results show that these methylene protons of the ethylene glycol unit resonate at lower field than those of the DDP aliphatic protons. The resonance intensity of DDP aliphatic protons increases with the increase of the phosphorus content. The H-1-n.m.r. spectrum of the DDP aliphatic protons contain three peaks since the proton in H-C-P has greater coupling constant than that of H-C-C. The chemical shifts of these methylene protons in the ethylene glycol unit vary with different sequences. The methylene protons in the ethylene glycol of the T-E-T unit resonate at lower field than those of P-E-T(T-E-P) and P-E-P units. The monomer molar fraction, sequential distribution and degree of randomness of the phosphorus-containing copolyester were determined through analyses of the resonances of methylene protons in the ethylene glycol unit. The molar fractions of the DDP comonomer determined by n.m.r. analyses are close to the charged values in synthetic step and the values determined by an UV method. Moreover, the copolyesters were found to be as random copolymers with a degree of randomness equal to about 1. (C) 1998 Elsevier Science Ltd. All rights reserved. |
URI: | http://hdl.handle.net/11536/32576 |
ISSN: | 0032-3861 |
期刊: | POLYMER |
Volume: | 39 |
Issue: | 14 |
起始頁: | 3233 |
結束頁: | 3240 |
顯示於類別: | 期刊論文 |