Injection moldable hybrid sustainable composites of BioPBS and PHBV reinforced with talc and starch as potential alternatives to single-use plastic packaging

Abstract

Single-use packaging is a major contributor to municipal solid waste and cause of plastic pollution worldwide, whereas the adoption of biodegradable alternatives is still hampered by significant challenges such as performance shortfalls and inadequate barrier properties. The present work utilizes compostable polymers, namely biobased poly(butylene succinate) (BioPBS) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), combined with hybrid natural fillers to achieve enhanced processability and barrier performances for substituting conventional plastic packaging. BioPBS reinforced with 20 wt.% talc showed improved barrier properties over the neat BioPBS, with both the oxygen and water vapor permeabilities improving by about 60%. With the blending of 20 wt.% PHBV, an overall further improvement of about 80% in both properties were achieved. The use of 1% maleic anhydride grafted BioPBS and BioPBS/PHBV-blend coupling agents enhanced the interfacial adhesion of the composites resulting in a consistent improvement of the tensile strength at yield and the oxygen barrier. The incorporation of 5% starch, which could potentially boost the biodegradability of the composites, helped in enhancing the toughness of the material at the expense of lowered barrier properties. Overall, the biocomposites demonstrated comparable mechanical properties to some commodity plastics such as polyolefins while having low oxygen and water permeability, showing great promise for applications in sustainable packaging.

Keywords

• Packaging
• Single-use
• Biodegradable
• Compostable
• Biobased
• Biocomposites