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Hydrolytic degradation of poly( l ‐lactic acid)/poly(methyl methacrylate) blends
Author(s) -
Boudaoud Naila,
Benali Samira,
Mincheva Rosica,
Satha Hamid,
Raquez JeanMarie,
Dubois Philippe
Publication year - 2018
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.5659
Subject(s) - differential scanning calorimetry , hydrolysis , materials science , methyl methacrylate , polyester , degradation (telecommunications) , crystallization , polymer chemistry , chemical engineering , hydrolytic degradation , scanning electron microscope , methacrylate , size exclusion chromatography , lactic acid , nuclear chemistry , composite material , copolymer , polymer , organic chemistry , chemistry , computer science , engineering , thermodynamics , enzyme , telecommunications , physics , genetics , biology , bacteria
The hydrolytic degradation of poly( l ‐lactic acid)/poly(methyl methacrylate) (PLLA/PMMA) blends was carried out by the immersion of thin films in buffer solutions (pH = 7.24) in a shaking water bath at 60 °C for 38 days. The PLA/PMMA blends (0/100; 30/70; 50/50; 70/30; 100/0) were obtained by melt blending using a Brabender internal mixer and shaped into thin films of about 150 µm in thickness. Considering that PMMA does not undergo hydrolytic degradation, that of PLLA was followed via evolution of PLA molecular weight (recorded by size exclusion chromatography), thermal parameters (differential scanning calorimetry (DSC)) and morphology of the films (scanning transmission electron microscopy). The results reveal a completely different degradation pathway of the blends depending on the polymethacrylate/polyester weight ratio. DSC data suggest that, during hydrolysis at higher PMMA content, the polyester amorphous chains, more sensitive to water, are degraded before being able to crystallize, while at higher PLLA content, the crystallization is favoured leading to a sample more resistant to hydrolysis. In other words, and quite unexpectedly, increasing the content of water‐sensitive PLLA in the PLLA/PMMA blends does not mean de facto faster hydrolytic degradation of the resulting materials. © 2018 Society of Chemical Industry