Abstract
To control the depolymerization of poly- l-lactic acid (PLLA) into l,l-lactide, effects of altering the physical and chemical properties of magnesium oxide (MgO) on its ability as a catalyst were investigated. Four kinds of MgO particles: MgO-heavy, 0.2, 0.05, and 0.01 μm, having primary particles of different dimensions, surface areas, and chemical structures/species were used. Thermo-gravimetric profiles of PLLA/MgO composites shifted into a lower temperature range due to an increase in the catalytic surface area resulting from a decrease in the dimensions of the MgO particles. However, decreasing the dimensions caused frequent side reactions with unfavorable products: cyclic oligomers and meso-lactide, due to the presence of different chemical structures/species. Heat treatment of the MgO particles not only effectively suppressed the oligomer production and enhanced the l,l-lactide production, but also accelerated the meso-lactide production at lower temperatures. These results indicate that the surface properties of MgO considerably influence the depolymerization of PLLA, with the catalytic behavior of MgO controllable by heat treatment and selection of the depolymerization conditions.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
