Biodegradable Blown Film Composites from Bioplastic and Talc: Effect of Uniaxial Stretching on Mechanical and Barrier Properties

Abstract

As public awareness about climate change grows, there is an increase in the research on bioplastic packaging films. This is the first-ever scientific report on uniaxially stretched biobased-polybutylene succinate-co-adipate (BioPBSA) and talc (15 and 25 wt%) based blown film composites at different stretch ratios (SR). The water vapor barrier properties of BioPBSA+25%Talc film at SR 4 shows an improvement of 40% compared to its unstretched counterpart, while an overall improvement of 48% is observed compared to the unstretched BioPBSA film. The successful dispersion of talc in the BioPBSA matrix, the orientation of talc filler during stretching, and the polymer chains orientation are responsible for such improvement. Additionally, XRD analysis shows that during uniaxial stretching, the crystallinity of the films increases by up to 26% as a result of strain-induced crystallization, with BioPBSA+25%Talc at SR 4 having the highest crystallinity (≈75%). Furthermore, the inclusion of 25% talc in BioPBSA considerably enhances the tensile modulus by 246% compared to its unstretched counterpart. Hence biodegradable films with balanced barrier and tensile properties may be promising alternatives to petroleum-based plastic materials used in flexible packaging applications.