การเตรียม การหาลักษณะเฉพาะ และการทดสอบสมบัติของคอมโพสิตชีวภาพของพีแอลเอ พีบีเอส และผงเปลือกลำไยที่ถูกดัดแปร

Abstract

This research is focused on the preparation, characterization and property testing of biocomposites of poly(lactic acid) (PLA), poly(butylene succinate) (PBS) and modified powdered longan shells. The biocomposites were prepared from the blends of PLA and PBS (85 :15 by weight) and longan powdered shells which treated in various of sodium hydroxide concentrations (2% and 5% w/v) and curing times (24 and 48 hrs). It was found that the biocomposites reinforced with unmodified powdered longan shells show better mechanical property than the modified one. The thermal properties of the biocomoposites with the modified longan shell powder show the decreasing of crystallization temperature (Tc) which indicates that the modified longan shell powder might act as nucleating agent. It was also found that Tc decreased as increasing the sodium hydroxide concentration or increasing curing time. The increasing of diffusion coefficient of water through biocomposites or the absorption behavior of biocomposites can be increased by the modification. Biocomposites reinforced with 10% of unmodified powdered longan shells show the highest modulus, stress and percentage strain (36739 ± 824 MPa, 87.49 ± 3.86 MPa and 75.21 ± 8.50% respectively). However, they show low rate of diffusion coefficient which similar to that of PLA/PBS blend. In conclusion, the biocomposites prepared from PLA, PBS and modified powdered longan shells can be controlled their properties by varying the compositions and conditions of the modification and have the potential to be the new biocomposites.