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

Abstract

A 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.

Thermal degradation kinetics of Opuntia Ficus Indica flour and talc-filled poly (lactic acid) hybrid biocomposites by TGA analysis

“…The apparent activation energy is observed % 157. KJ/ mol by the FWO method; a similar value was observed by Xu et al 39 The KAS method uses a more precise solution values that are for the integral temperature; therefore, it provides more accurate values.…”

“…These methods are widely used in biomass kinetic analysis. 39 The degradation response for all types of nonisothermal kinetics investigations can be described by equation (1). 54…”

“…37 In addition, the thermal degradation kinetics and reaction mechanisms of PLA and its biocomposites need to be understood to better control thermal decomposition, avoid thermal degradation, and maintain mechanical properties. 38,39 Based on TGA data, kinetic parameters can be measured from the calculated results using model-fitting and modelfree solid-state kinetic models that could help to understand the process under study and verify the validity of the assumptions as well as reach quantitative conclusions. Kinetic analysis of plastics can guide the thermal degradation process from the perspective of reactor design and provide a theoretical basis for industrialization.…”

“…The activation energy of PLA/barium sulfate (BaSO 4 ) composites was increased by Xu et al, showing that the presence of inorganic fillers has an inhibitory effect on the thermal degradation of PLA. 39 Alvarez et al, used a number of differential and integral kinetic methods to analyze the kinetic parameters of industrial mixtures of starch and cellulose derivatives with sisal fibers. The authors noted that for all methods and even for these biocomposites, the activation energy remained the same.…”

Roles of physical filling and chemical crosslinking on the physico‐mechanical properties of polylactic acid

“…1 In this context, bio-based and biodegradable polymers have aroused wide concern due to their environmentally friendly and renewable features. 2,3 Polylactic acid (PLA), as a bio-based and biodegradable thermoplastic polyester, 2,4 is derived from a stream of renewable plant resources, such as wheat, corn, and sugarcane, [4][5][6][7][8] and can be completely degraded by soil microorganisms. 8 However, PLA is a rigid and brittle polymer 6,[9][10][11] with poor toughness and impact resistance.…”