ISSN:
0449-296X
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The kinetics of the solid-state polymerization of the N-carboxy anhydrides (NCA) of the L- and racemic forms of γ-benzyl glutamate (BG), γ-methyl glutamate (MG), and ∊-carbobenzoxylysine (CL) were studied as a function of temperature and aqueous vapor pressure. The reaction of the L-forms of BG and MG was characterized by an induction period, while the CL derivative reached its maximum polymerization rate at the outset of the reaction. Water vapor had only a minor effect in accelerating the reaction and reducing the chain length of the polypeptides formed. The racemic monomers were found to have different crystal structures from those of the L-isomers and the racemic MG and CL derivatives polymerized much more slowly than the corresponding optically active crystals. All polymers gave diffuse x-ray diffraction patterns. Infrared spectra of the L-polypeptides showed that they were largely in the α-helical form. The polymer derived from the racemic BG-NCA had a content of α-helical material which suggested that it consisted of polypeptides with long blocks of D and L residues.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1966.150040619
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