Injection moulded composites from high biomass filled biodegradable plastic: Properties and performance evaluation for single-use applications

Biodegradable plastic-based items play an essential role in ensuring the sustainability of the food packaging industry due to their high biodegradability and minimized use of fossil fuels. The incorporation of low-cost waste biomass into bio-based polymers to produce biodegradable composites supports the circular economy model and reduces landfilling and carbon footprint challenges associated with petroleum-based plastics. This work discusses the utilization of waste almond shell powder (ASP) up to 50 wt.% with poly(butylene succinate-co-butylene adipate) (PBSA) to develop sustainable biocomposites through injection moulding for rigid packaging applications. At a lower angular frequency (0.1 s − 1), the complex viscosity of the PBSA/50%ASP biocomposite was reduced by ∼65% after adding 5 wt.% compatibilizer, as confirmed by a rheological analysis. The heat deflection temperature, flexural strength, and tensile and flexural moduli of the PBSA/50% ASP biocomposite with 5 wt.% compatibilizer were improved by ∼24, 125, 368, and 385%, respectively, compared to pristine PBSA. These improvements are attributed to the high stiffness and load-bearing capacity of ASP and the enhanced interfacial adhesion and particle dispersion caused by the compatibilizer, as corroborated by SEM analyses. Hence, the formulated biocomposites show a suitable structure-property-processing co-relationship for injection moulding of single-use products.