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Polymerization of amino acid derivatives by polymer catalysts. III. Chain effect polymerization induced by poly( N ‐ethylglycine) diethylamide
Author(s) -
Sisido Masahiko,
Imanishi Yukio,
Okamura Seizo
Publication year - 1969
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1969.360070609
Subject(s) - chemistry , polymerization , polymer chemistry , polymer , degree of polymerization , amine gas treating , catalysis , adsorption , organic chemistry
The polymerization of D , L ‐β‐phenylalanine NCA induced by preformed polyi( N ‐ethylglycine) diethylamide having a terminal secondary amino group was investigated. The polymerization was much faster than the same reaction initiated by a low molecular weight amine of similar base strength. Hence, the chain effect is operative with poly ( N ‐ethylglycine) diethylamide as well as polysarcosine diethylamide, with which Bamford et al. found the chain‐effect mechanism. The polymerization rate was dependent on the degree of polymerization of the polymer catalyst. The rate enhancement was attributed to adsorption of the NCA onto the amide carbonyl groups of the polymer chain by the formation of hydrogen bond. In going from polysarcosine diethylamide to poly ( N ‐ethylglycine) diethylamide, the absorptivity of NCA on on the polymer chain was little affected. However, the reaction between an adsorbed NCA and a terminal base was more difficult with poly ( N ‐ethylglycine) diethylamide than with polysarcosine diethylamide. This may be related to differences in flexibility of the polymer chain.