Isosorbide plasticized corn starch filled with poly (3-hydroxybutyrate-co-3-hydroxyvalerate) microparticles: Properties and behavior under environmental factors

In this work, new green and fully biodegradable composites, based on corn starch, plasticized with two different amounts of isosorbide and filled by poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microparticles, were obtained by melt processing. The analysis of their morphologies, crystallinity, structural interactions and dynamomechanical properties as well as the evaluation of their moisture resistance and biodegradability in soil, were performed in function of the plasticizer and/or microparticle amount.The analysis of morphology, crystallinity and structural interactions showed that the plasticization process was completed under the melting processing conditions used. The microparticles were homogeneously dispersed in the thermoplastic starch matrix without suffering any deformation or breaking during the processing. Biocomposites with adequate storage modulus values were obtained, especially the TPS plasticized with 35% of isosorbide and filled with 5 wt% of PHBV microparticles. The incorporation of PHBV microparticles leads to biocomposites with higher moisture resistance. All the biocomposites were completely biodegraded in soil in a short period of time. The performed study demonstrated that these biocomposites could be used for applications in the packaging industry.

Automated summary

In this work, green and fully biodegradable composites based on corn starch were successfully obtained by melt processing. The effects of different amounts of isosorbide plasticizer and PHBV microparticles on the composites' properties were studied. The results showed that the plasticization process was completed and the microparticles were homogeneously dispersed in the thermoplastic starch matrix without deformation or breaking. The biocomposites with suitable storage modulus and improved moisture resistance were completely biodegraded in soil, indicating their potential application in the packaging industry.