Investigation on the environmental‐friendly poly(lactic acid) composites based on precipitated barium sulfate: Mechanical, thermal properties, and kinetic study of thermal degradation

Abstract

ABSTRACTA novel environmental‐friendly poly(lactic acid) (PLA) composites based on precipitated barium sulfate (BaSO4) were prepared via melt‐compounding. The mechanical properties and thermal stability of PLA/BaSO4 composites were investigated. To dig the decomposition mechanism, kinetic analysis of thermal degradation was emphasized systematically based on nonisothermal thermograms. Results showed that the mechanical responses were improved remarkably both under the quasi‐static condition and subjected to high‐speed shock due to the well‐bonded interfaces between PLA and BaSO4. Meanwhile, the added BaSO4 suppressed the mass conversion rate of PLA phase and improved the thermal stability at high temperature. Due to the inhibition of BaSO4, the calculated activation energy was enhanced obviously according to model‐free isoconversional approaches. Finally, the apparent kinetic mechanism and reaction order for the over‐all thermal degradation were determined by the combination of model‐fitting approaches and Carrasco method. From this study, we hope to provide a facile method to prepare environmental‐friendly PLA composites with excellent mechanical properties and thermal stability. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47995.