< 전시-P-40 > A study on the Thermal Properties of Wood Flour/SEBS-g-MAH/Nano Clay-filled Polylactic Acid Composites = < 전시-P-40 > A study on the Thermal Properties of Wood Flour/SEBS-g-MAH/Nano Clay-filled Polylactic Acid Composites

다국어 초록 (Multilingual Abstract)

Recently, as interest in environmentally friendly materials has increased, studies on the development of new materials using various biodegradable plastics have been conducted. Poly(lactic acid)(PLA), one of the biodegradable plastics, synthesized from renewable resources has become popular due to their sustainability, biodegradability, and transparency. In this study, PLA composites were prepared by incorporating wood flour(WF), maleic anhydride grafted styrene-ethylene/butylene-styrene copolymer(SEBS-g-MAH), and nano clay. SEBS-g-MAH and nano clay were mixed at the same ratio and used as a master batch. The materials used in the study were first compounded with a twin screw extruder and then pelletized using a pelletizer. Thermal properties of PLA composites were analyzed by thermogravimetric analysis(TGA) and differential scanning calorimetry(DSC).
GA results showed that the thermal stability of PLA/WF composite was reduced compared to PLA only due to the relatively low thermal decomposition temperature of WF. However, the thermal stabilities of the PLA/WF composites were improved in the presence of SEBS-g-MAH/nano clay master batch. This is because the SEBS-g-MAH having thermally stable styrene component binds to the WF surface and forms strong interfacial bondings between WF and PLA matrix. In DSC results of the PLA/WF composites, decreases in glass transition temperatures were observed. It is considered that the addition of WF interferes with the interaction of the PLA polymer chain, which increases the fluidity of the polymer. Besides, the crystallinity of PLA composites decreased with the addition of SEBS-g-MAH/nano clay master batch. This suggests that the presence of SEBS-g-MAH affects the efficiency of nucleation in the crystallization of PLA. SEBS-g-MAH, therefore, effectively improved the thermal properties of PLA/WF composites and it could be used as an promising additive in PLA/WF composites.