Customizing the Hydrolytic Degradation Rate of Stereocomplex PLA through Different PDLA Architectures
2012 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 13, no 4, 1212-1222 p.Article in journal (Refereed) Published
Stereocomplexation of poly(L-lactide) (PLLA) with star shaped D-lactic acid (D-LA) oligomers with different, architectures and end-groups clearly altered the degradation rate and affected the degradation product patterns. Altogether, nine materials were studied: standard PLLA and eight blends of PLLA with either 30 or 50 wt % of four different D-LA. oligomers. The influence of several factors, including temperature, degradation time, and amount and type of D-LA oligomer, on the hydrolytic degradation process was investigated using a fractional factorial experimental design. Stereocomplexes containing star shaped D-LA oligomers with four alcoholic end-groups underwent a rather slow hydrolytic degradation with low release of degradation products. Materials with linear D-LA oligomers exhibited similar mass loss but released higher concentrations of shorter acidic degradation products. Increasing the fraction of D-LA oligomers with a linear structure or with four alcoholic end-groups resulted in slower mass loss due to higher degree of stereocomplexation. The opposite results were obtained after addition of D-LA oligomers with carboxylic chain-ends. These materials demonstrated lower degree of stereocomplexation and larger mass and molar mass loss, and also the release of degradation products increased. Increasing the number of alcoholic chain-ends from four to six decreased the degree of stereocomplexation, leading to faster mass loss. The degree of stereocomplexation and degradation rate were customized by changing the architecture and end-groups of the D-LA oligomers.
Place, publisher, year, edition, pages
2012. Vol. 13, no 4, 1212-1222 p.
Enantiomeric Poly(Lactic Acid)S, Bio-Based Polymers, Polylactide Stereocomplex, Crystallization Behavior, Poly(L-Lactic Acid), Spherulite Growth, Product Patterns, End-Group, Melt, Hydrophilicity
Biochemistry and Molecular Biology
IdentifiersURN: urn:nbn:se:kth:diva-95108DOI: 10.1021/bm300196hISI: 000303076200032PubMedID: 22394150ScopusID: 2-s2.0-84860711835OAI: oai:DiVA.org:kth-95108DiVA: diva2:527755
FunderEU, European Research Council, NMP2-CT-2007-026515
QC 201205222012-05-222012-05-142013-04-03Bibliographically approved