Preparation, compatibility and barrier properties of attapulgite/poly (lactic acid)/thermoplastic starch composites

Abstract

In this study, AT (attapulgite)/PLA/TPS biocomposites and films were prepared by melt blending technique using PLA and TPS as matrix, polyethylene glycol (PEG) as plasticizing modifier of PLA and AT clay as additive. The effect of AT content on the performance of AT/PLA/TPS composites was investigated. The results showed that, as the AT concentration increased, the fracture surface of the composite showed a bicontinuous phase structure when the AT content was 3 wt%. The rheological properties showed that the addition of AT resulted in more significant deformation of the minor phase, which reduced the phase size and led to lower complex viscosity, and more processability from the industrial perspective. The mechanical properties showed that the addition of AT nanoparticles could simultaneously improve the tensile strength and elongation at break of the composites, reaching a maximum at 3 wt% load. The water vapor barrier performance results showed that AT significantly improved the WVP of the film, and the moisture resistance performance was increased by 254 % compared with the PLA/TPS composite film within 5 h. In conclusion, the obtained AT/PLA/TPS biocomposites showed potential in packaging engineering and injection molding products, especially when renewability and full biodegradability of the material are required.