Polymerization of γ-benzyl-l-glutamate N-carboxy anhydride initiated by α,ω-primary diamines in N,N-dimethylformamide

✍ Scribed by Etsco Hasegawa; Toshiaki Shibata; Haruyuki Takeuchi; Eishun Tsuchida

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 317 KB
• Volume: 13
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(77)90200-2

✦ Synopsis

The polymerization of 7-benzyl-L-glutamate N-carboxy anhydride initiated by ~,~-primary diamines was studied kinetically in N,N-dimethylformamide by measuring the amounts of carbon dioxide evolved during polymerization and compared with those initiated by ~-primary monoamines. The pseudo first-order plots were linear in both cases. The ratio of the pseudo first-order rate constant of the first step to that of the second step was about 2.1 in the polymerization initiated by the diamines and about 1.3 for the monoamines. The number-average degrees of polymerization of growing polymers at the transition point were from 6 to 9 in the former cases, but from 10 to 13 in the latter. Acceleration in the polymerization initiated by the ~,o-diamines could be explained by the reaction between N-CA absorbed on one block of the growing polymer and the growing end of another block in the same polymer-chain.