Migration and hydrolysis of hydrophobic polylactide plasticizer.
Hydrophobic plasticizer protects polylactide (PLA) against hydrolytic degradation but still migrates to aging medium and there undergoes further hydrolysis contributing to the spectrum of degradation products. PLA plasticized with hydrophobic acetyl tributyl citrate (ATC) plasticizer showed a slower degradation rate compared with pure PLA because of the increased hydrophobicity of the material. The enhanced bulk hydrophobicity also overcame the degradation enhancing effect of hydrophilic surface grafting. In addition to plasticization with ATC, some of the samples were also surface grafted with acrylic acid. The materials were subjected to hydrolysis at 37 and 60 degrees C for up to 364 days to compare the effect of hydrophobic and hydrophilic bulk and surface modifications. Although considered insoluble in water, the plasticizer was detected in the water solutions immediately upon immersion of the materials, and the relative abundance of the ATC degradation products increased with hydrolysis time.
Höglund
Anders
A
Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology, S-100 44, Stockholm, Sweden.
Hakkarainen
Minna
M
Albertsson
Ann-Christine
AC
D000179:Acrylates / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D002850:Chromatography, Gel; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D010968:Plasticizers / Q000737:chemistry* / Q000378:metabolism*; D011091:Polyesters / Q000737:chemistry* / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D013499:Surface Properties; D014867:Water / Q000737:chemistry
D000179:Acrylates; D010968:Plasticizers; D011091:Polyesters; D014867:Water; C033616:poly(lactide); C036658:acrylic acid