Biodegradable polyhydroxybutyrate/cellulose/calcium carbonate bioplastic composites prepared by heat‐assisted solution casting method

Abstract

AbstractPolyhydroxybutyrate (PHB) is a sought‐after alternative biopolymer to synthetics with its high biodegradability and similar properties to available polymers. However, its high production cost narrows its market application. In this study, cheap, biocompatible, and widely available fillers such as cellulose (CL) and calcium carbonate (CC) were incorporated into PHB using a heat‐assisted solution casting method to reduce the manufacturing cost of the bioplastic while retaining its properties. Characterization tests found that both natural fillers have relatively low miscibility with PHB which may be accounted for by self‐ and co‐agglomeration of the fillers while having improved thermal stability. The Young's modulus of the bioplastic films increased with the introduction of CC, while the mechanical property slightly decreased upon the addition of CL attributing to the aggregation of fillers. Full biodegradation of all composites within 8 weeks was observed in the compost biodegradability tests; PHB 90 CC 10 biodegraded the slowest after the 50th day, while PHB 90 CL 10 fully disintegrated after the 30th day. Further improvements such as the incorporation of cheap, naturally derived crosslinkers or plasticizers can greatly improve the properties of the synthesized biocomposites.