Property improvement of processed PLA/PBAT using chain extenders

Abstract

The polymer blend of poly(lactic acid)/poly(butylene adipate-co-terephthalate) (PLA/PBAT), commercially named Ecovio, is a biodegradable plastic with a high level of strength and toughness. Despite the development of biodegradable plastics with improved characteristics and greater applicability, their cost remains prohibitively high preventing their widespread use. One approach to reducing production costs is recycling manufactured waste plastics. However, in this process, the properties of plastic are typically changed due to chain scissions during thermal reprocessing. Using an additive such as a chain extender is thought to reconnect cleaved polymer chains. Therefore, the purpose of this research is to investigate the influences of two chain extenders, multifunctional epoxide and multifunctional imide, on the mechanical properties and thermal properties as well as the melt flow rate of Ecovio. Materials were processed and blended using a twin-screw extruder and formed into film samples via the blow film extrusion process. The findings revealed that the addition of chain extenders resulted in a higher viscosity of Ecovio. In the thermal properties test, it was found that the use of chain extenders resulted in shifts in the glass transition, crystallization, melting temperature, and thermal stability of Ecovio. Finally, the result of mechanical properties test illustrated that Young’s modulus and tensile strength of thermal processed Ecovio were changed and improved by blending with virgin Ecovio and chain extenders.

Keywords

• chain extenders
• reprocessing
• thermal properties
• mechanical properties
• viscosity