| Summary: | The purpose of this study is to improve the mechanical properties of polylactic acid (PLA) by incorporating liquid epoxidized natural rubber (LENR) and graphene oxide (GO). The effect of adding grafted GO and LENR (GO-g-LENR) and non-grafted (GO/LENR) on the properties of PLA composite was determined. Firstly, the best formulation of LENR was determined by blending PLA with LENR by melt blending using internal mixer, followed by compression moulding. Their mechanical, thermal and morphological properties were characterized. The composition of LENR were varied from 0, 5, 10, 15 and 20 wt%. Mechanical analysis showed that impact properties of PLA/LENR increased with increasing of LENR content up to 10 wt% LENR. However, the sample did not show good improvement in tensile and flexural properties. Thermogravimetric analysis data showed the increase in thermal stability of PLA/LENR. Field emission scanning electron microscopy (FESEM) revealed that better dispersion of LENR in PLA matrix occurred at 10 wt% LENR. PLA/LENR10 (10 wt% LENR) was chosen to be the best composition for the incorporation of GO to the sample. GO-g-LENR was successfully grafted at different content of GO loading (1, 3 and 5 phr) and confirmed with Fourier transform infrared spectroscopy analysis. GO-g-LENR was blended with PLA and the mechanical, thermal and morphological properties were compared with PLA/LENR/GO (non-grafted) composite. The incorporation of 1 phr GO improved the impact, tensile and flexural properties for both grafted and non-grafted samples with higher improvement showed by grafted composite. Thermal stability of the composite improved significantly as observed at Td10% and Td60%. Sample of PLA/5GO-g-LENR showed the highest residue mass at 800 ℃. FESEM analysis on the fractured surface of PLA/1GO-g-LENR showed better dispersion of GO whereas sample of PLA/LENR/3GO revealed the agglomeration of GO in the composite. Overall, properties of PLA/GO-g-LENR showed higher properties enhancement compared to PLA/LENR/GO composite.
|
|---|
