Development of biodegradable polymer composites

• Main Author: Ruan, Wei.
• Other Authors: Li Lin
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/53989
• Institution: Nanyang Technological University

Poly (lactic acid) (PLA) is a well-known biodegradable polymer. It can be obtained from the renewable agricultural crop such as corn, potatoes and waste produce. Recently, PLA has garnered a lot of attention as a result of growing environmental awareness. The application of PLA is mainly restricted by its brittleness and slow crystallization. Incorporating PLA with nanofillers is a possible method to enhance the properties of PLA significantly. Nanoclay and rubber based toughening agent were employed in this study to investigate the influences of nanofillers and toughening agent on mechanical and thermal properties of PLA. Poly (lactic acid) (PLA)/ nanoclay/ toughening agent composites were prepared by melt extrusion of PLA, nanoclay and toughening agent using a twin-screw extruder. The mechanical and thermal properties of PLA and PLA composites were investigated with varying formulations of PLA, nanoclay and rubber. The filler amount was varied in the range from 0 to 10wt%. Tensile test result had shown that the Young’s modulus of the PLA/clay and PLA/rubber nanocomposites had increased significantly as compared to the neat PLA, while this value dropped dramatically with incorporating clay and rubber. The addition of fillers did not affect the strength of PLA significantly. However, adding clay into the PLA matrix reduced the tensile strain at break of PLA, whereas adding rubber into PLA increased the strain as well as toughness. This showed that rubber is a good toughening agent. Clay and rubber particles reduced the initial decomposition temperature of PLA indicating lower thermal stability of PLA/clay, PLA/rubber and PLA/clay/rubber composites. The effects of clay and rubber on other thermal properties such as glass transition temperature (Tg), cold crystallization temperature (Tcc) and melting temperature (Tg) were also discussed in this project. The crystallinity of PLA improved significantly by adding clay particles, indicating that nanoclay might behave as nucleating agent in PLA/clay nanocomposites.