Increased degradation of PLA/PBAT blends with organic acids and derivatives in outdoor weathering and marine environment

Bio-Flex (R) is a commercial blend of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) used in several industrial and daily applications. To understand the degradation behavior of this mixture, two laboratory tests were conducted, one simulating outdoor accelerated weathering (OAW) and the other mimicking degradation in marine environments in seawater (MES). To increase its degradability, Bio-Flex was mixed with various additives such as chloroacetic acids -trichloroacetic acid (TCA) and dichloroacetic acid (DCA) -and esters of the latter. The samples were characterized before and after the degradation tests by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and mechanical properties. Size exclusion chromatography (SEC) and contact angle were also evaluated. The acids were found to be very effective in degrading PLA/PBAT blends, even during the blending process. It follows that the esters of DCA are suitable as good additives to increase the degradation ratio of the PLA/PBAT blend when an enhanced degradation process is required.

Automated summary

This study investigated the degradation behavior of Bio-Flex (R), a blend of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT), through simulated laboratory tests simulating outdoor accelerated weathering (OAW) and degradation in marine environments in seawater (MES). The results showed that acids were highly effective in degrading the PLA/PBAT blend, even during the blending process. The esters of DCA were found to be suitable additives for enhancing the degradation process of the PLA/PBAT blend.