Mechanical and Thermal characterisation of Polylactic acid (PLA) based bio-composites

摘要

Advancements in natural fibers reinforced composites are developing for cost-effective "green products" to be used in a wide range of applications. Biocomposites with improved mechanical properties and thermal stability using natural fibers is one of these recent developments. Polymers that are derived from renewable resources (e. g. derived from plant-based feedstocks or from bacterial fermentation) are getting attention in industrial applications in the recent past. They have been recently developed in response to mounting needs for finding a substitute for fossil fuel-based polymers. Poly lactic acid(PLA) is the most promising amongst the biopolymer's family. Its use can be limited because of its poor mechanical and lower thermal stability alongside some processing difficulties. The objective of this research was to investigate and improve the mechanical and thermal properties of PLA by developing bio-composites reinforced with natural fibers (Hemp). Young's Modulus increased significantly from 4.1 ± 0.74 to 9.32 ± 0.86 GPa when contents of hemp increased from 0 to 30 (wt%). It is appeared that the overall crystallinity of the PLA-Hemp composites remains unchanged but double peak observed in melting endotherm indicate that there are two different sperulite types or crystalline forms. In terms of visocelastic behaviour of the composites, the storage modulus increased from 3.20 ± 0.37 to 4. 58 ± 0.61 GPa when the contents of hemp fibres increased from 0 to 30 (wt%).