Effect of degree of polymerization and steric configuration of poly(2-vinylpyridine) as catalyst in the polymerization of phenylalanine NCA

✍ Scribed by Yukio Imanishi; Shoji Nagaoka; Kazuhiro Suzuoki; Toshinobu Higashimura

• Publisher: Wiley (John Wiley & Sons)
• Year: 1973
• Tongue: English
• Weight: 487 KB
• Volume: 12
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1973.360120117

✦ Synopsis

Abstract

Despite its being weaker base poly(2‐vinylpyridine) polymerized DL‐β‐phenylalanine NCA at a much faster rate than pyridine and α‐picoline. Poly(2‐vinylpyridine) adsorbs NCA by hydrogen bonding with the cooperation of a few pyridine groups. This results in a high local concentration of NCA. The syndiotactic configuration of pyridine group seemed to be least suitable for the cooperative hydrogen bonding. Adsorbed NCA is activated to form an “activated” NCA which in turn reacts with an NCA adsorbed on the same polymer chain. Since the polymer chain is flexible, this intramolecular reaction takes place frequently, resulting in the acceleration of polymerization. The intramolecular reaction along the polymer chain is dependent on the degree of polymerization of polymer catalyst. A suitable model was proposed for the intramolecular reaction to explain the effect of degree of polymerization.