Document Detail


Characteristic Chain-End Racemization Behavior during Photolysis of Poly(L-lactic acid).
MedLine Citation:
PMID:  21790202     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
Photolysis of poly(L-lactic acid) (PLLA) has many unclear points, such as the degradation mechanism, kinetics, products, and racemization mechanism. To clarify these features of PLLA photolysis, the relationship between photolysis and racemization was examined. The hexad stereosequential analysis of photodegraded PLLA was investigated to specify the racemized positions within a chain in comparison with hydrolysis and thermal degradation. Results from 13C NMR spectra of UV-irradiated PLLA samples indicated that the samples have racemized D-lactate units at chain-ends. From the comparison of racemization behavior among photolysis, hydrolysis, and thermal degradation, it was confirmed that the preferential racemization behavior of each of these three degradation processes is characteristic and distinct, being identified as chain-end racemization, poor racemization, or internal-unit racemization, respectively. The characteristic chain-end racemization behavior of photolysis was first confirmed in this study.
Authors:
Nobuhiko Yasuda; Takayuki Tsukegi; Yoshihito Shirai; Haruo Nishida
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-7-27
Journal Detail:
Title:  Biomacromolecules     Volume:  -     ISSN:  1526-4602     ISO Abbreviation:  -     Publication Date:  2011 Jul 
Date Detail:
Created Date:  2011-7-27     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100892849     Medline TA:  Biomacromolecules     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
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