Enhancing thermal stability and tensile performance of short basalt fiber-reinforced PLA composites with PBAT and nano-silica

Short fiber-reinforced polylactic acid composites (SFRPLA) have significant potential in diverse industries. The inherent propensity of SFRPLA to degrade at elevated temperatures underscores the critical importance of its thermal stability for high-temperature applications. In this work, poly-(butylene adipate-co-terephthalate) (PBAT) is melt-blended with PLA by incorporating nano-silica, and then reinforced with short basalt fiber (SBF) to fabricate PLA-ternary composites (SBFRPLA-ns). Then study the morphology, microstructure, and thermal properties of SBFRPLA-ns to understand the internal composition and interaction between the components and explore the modification mechanism of SBFRPLA-bio composites. The results show that the maximum tensile modulus and crystallinity of SBFRPLA-ns surpassed those of pure PLA by 103% and 185.5%, respectively. Subsequent analysis using WAXD and FTIR demonstrates that SBFRPLA-ns undergo no discernible phase change and maintain their structural similarity to PLA. Furthermore, TG/DTG at different heating rates confirms the beneficial influence of the components on the thermal stability of SBFRPLA-ns. Accordingly, breaking the key technical barriers to improve the mechanical properties and thermal stability can expand the high-temperature application potential of SBFRPLA-bio.