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Polylactic Acid and Polylactic Acid-Based Nanocomposite Photooxidation.
MedLine Citation:
PMID:  20942482     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
The importance of photooxidation in promoting formation of anhydride functional groups and thus promoting hydrolysis/biodegradation of polylactic acid and PLA nanocomposites were elucidated. PLA-based nanocomposites were prepared by adding 5% wt filler content of sodium montmorillonite (ClNa), sodium montmorillonite partially exchanged with Fe(III) (ClFe), organically modified montmorillonite (Cl20A), unmodified sepiolite (SEP), and fumed silica (SiO(2)). The pure PLA and nanocomposites were UV-light irradiated in artificial accelerated conditions representative of solar irradiation (λ > 300 nm) at 60 °C in air. The chemical modifications resulting from photooxidation were followed by IR and UV-visible spectroscopies. The infrared analyses of PLA photooxidation show the formation of a band at 1845 cm(-1) due to the formation of anhydrides. A photooxidation mechanism based on hydroperoxide decomposition is proposed. The mechanism proposed is confirmed by an increase in anhydride formation rate: the main responsible for this acceleration was identified as transition metals contained in the nanofillers as impurities and involved in the catalytic hydroperoxide decomposition.
Authors:
Sergio Bocchini; Kikku Fukushima; Alessandro Di Blasio; Alberto Fina; Alberto Frache; Francesco Geobaldo
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2010-10-13
Journal Detail:
Title:  Biomacromolecules     Volume:  -     ISSN:  1526-4602     ISO Abbreviation:  -     Publication Date:  2010 Oct 
Date Detail:
Created Date:  2010-10-14     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100892849     Medline TA:  Biomacromolecules     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
Dipartimento di Scienze dei Materiali ed Ingegneria Chimica, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
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