Influence of acrylic impact modifier on plasticized polylactide blown films

The tearing fracture surface of PLA/PDEGA/ACR blown films could be observed by using SEM. A clear matrix deformation could be clearly identified. It was a typical feature of a ductile fracture. Polylactide (PLA) was first plasticized with polydiethylene glycol adipate (PDEGA). Then the plasticized PLA was further blended with acrylic impact modifier (ACR) using a twin‐screw extruder. Finally, the extruded samples were blown using the blown thin film technique. Both PDEGA and ACR significantly affected the physical properties of the films. The results indicated that elongation at break and the tear strength of the films were significantly improved. The cavitation and large plastic deformation observed in films subjected to the tear test were the important energy‐dissipation process, which led to a torn PLA film. Moreover, the PLA/PDEGA/ACR blown films had excellent optical properties. ACR could act as a tear resistance modifier for PLA blown films. These findings contribute new knowledge to the additives area and give important implications for designing and manufacturing polymer packaging materials. © 2013 Society of Chemical Industry