Nonisothermal crystallization behavior and mechanical properties of poly(lactic acid)/ramie fiber biocomposites

Poly(lactic acid) (PLA) and PLA/natural fiber composites are considered as environmentally friendly materials and are becoming one of the research hotspots. Many research achievements of PLA and its composites prefer to focus on modification and the macro-properties of composites while there are few works on relationships between processing, structures, and properties. The ramie fiber (RF) reinforced PLA biological composites were prepared and PLA/RF injection-molded samples were fabricated to investigate effects of RF percentage (0, 5 wt% RF, 10 wt% RF, 15 wt% RF, 20 wt% RF) on PLA crystallization, thermal and mechanical performance by experimental and numerical methods. Experimental and simulated results indicate that the RF serves as a kind of nucleation agent, accelerates the crystallization rate, shortens the half crystallization time of PLA. The degree of crystallinity is up to 16.2% when PLA is with 20 wt% RF. The half crystallization time of PLA with 5 wt% RF composite is reduced by up to 28%. Correspondingly, the tensile strength and Young's modulus of the PLA composites are also improved by the RF without sacrificing thermal stability.

Automated summary

Poly(lactic acid) (PLA) and PLA/natural fiber composites are considered environmentally friendly materials and have become a research hotspot. This study investigated the effects of ramie fiber (RF) content on the crystallization, thermal, and mechanical properties of PLA composites through experimental and numerical methods. The results showed that RF accelerated the crystallization rate of PLA, leading to improved tensile strength and Young's modulus without sacrificing thermal stability.