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

Bio-Flex® 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. [Display omitted] •Chloroacetic acids could be used to increase PLA/PBAT blends degradability.•Weathering exposure degrades polymers quickly than marine environments.•Amorphous phase is degraded in a preferential way than crystalline phase.•Esters of dichloroacetic acid are effective in increasing degradability too.