Property Improvement of Polybutylene Succinate (PBS), Polyhydroxybutyrate (PHB), and Polylactic Acid (PLA) Films with PCL (Polycaprolactone) for Flexible Packaging Application

Abstract

Nowadays, developing highly biodegradable polymer films for flexible packaging applications is one of many researchers' demanding and challenging tasks. Conventional plastics/polymers are still being extensively used, creating environmental pollution. Because most of the commercially available plastic products are marketed as biodegradable are not truly biodegradable and have several limitations for making flexible packaging films. The main objective of this work is to manufacture biodegradable polymer blends, with the best performance characteristics, for flexible packaging applications. The paper focused on improving the properties, i.e., tensile, barrier, and biodegradation properties, of commercially available polymers such as Polybutylene succinate (PBS), Polyhydroxybutyrate (PHB), and Polylactic acid (PLA) by blending with Polycaprolactone (PCL) for flexible packaging application. Polymer films of various compositions such as PBS-PCL, PHB-PCL, and PLA-PCL blends were fabricated by injection molding and hot pressing. The characterization analysis included analyzing polymer blends' tensile and water vapor barrier properties, as per ASTM D882-18 method and ASTM E96-16 method, respectively, following that biodegradation analysis in compost (ASTM D5338-15 method) and seawater medium (ASTM D6991-17 method) of the polymer blends, and analysis of PCL blends' effect. The research showed that compared to the pure polymer blends such as PBS, PHB, and PLA blends, polymer blends with 20% of PCL has increased tensile elongation by 26.3%, 68%, and 171%, respectively, and the water vapor barrier properties were increased by 28.3%, 26.8%, and 30.3%. the biodegradation rate in compost medium was increased by 21.9%, 6.4% and 21.2%, and the biodegradation rate in seawater medium was increased by 31%, 7.5%, and 16.6%, respectively, even though a slight decrease in tensile strength. In conclusion, the polymer blends with 20wt% of PCL provide overall improved of polymer properties.