A comparative study on the mechanical, thermal and morphological characterization of poly(lactic acid)/epoxidized...

Area of Science:

• Polymer Science
• Materials Science
• Biomaterials Engineering

Background:

• Poly(lactic acid) (PLA) is a biodegradable thermoplastic with desirable properties but suffers from inherent brittleness.
• Enhancing PLA's mechanical and thermal performance is crucial for expanding its applications.
• Epoxidized palm oil (EPO) is explored as a potential modifier for PLA.

Purpose of the Study:

• To investigate the effects of incorporating different epoxidized palm oil (EPO) types and concentrations into a poly(lactic acid) (PLA) matrix.
• To enhance the flexibility, mechanical strength, and thermal stability of PLA.
• To evaluate EPO as a potential plasticizer for PLA.

Main Methods:

• Melt blending of PLA with varying weight percentages (1-5 wt%) of three distinct EPO types.
• Characterization using Scanning Electron Microscopy (SEM) for morphology, tensile testing for mechanical properties, Differential Scanning Calorimetry (DSC) for thermal transitions, and Thermogravimetric Analysis (TGA) for thermal stability.

Main Results:

• SEM analysis confirmed successful modification of PLA's brittle morphology.
• Addition of 1 wt% EPO significantly improved PLA's tensile strength, flexibility, flexural, and impact properties.
• DSC indicated a decrease in glass transition temperature (T(g)) with EPO addition, suggesting increased chain mobility.
• TGA revealed a 27% increase in thermal stability at 1 wt% EPO.
• EPO(3) demonstrated superior performance at an optimal 1 wt% loading.

Conclusions:

• Epoxidized palm oil (EPO) effectively mitigates the brittleness of poly(lactic acid) (PLA).
• Optimal addition of 1 wt% EPO enhances key mechanical and thermal properties, with EPO(3) showing the best results.
• EPO presents a promising, sustainable plasticizer for improving PLA's overall performance and applicability.