Effect of empty fruit bunches microcrystalline cellulose (MCC) on the thermal, mechanical and morphological properties of biodegradable poly (lactic acid) (PLA) and polybutylene adipate terephthalate (PBAT) composites

Abstract

Nowadays, awareness of the environment is rising among society. Thus, more researches on the utilization of biodegradable polymer as an alternative to non-biodegradable polymers have been published. Among various biopolymers, Poly (lactic acid) (PLA) and polybutylene adipate terephthalate (PBAT) have received a lot of attention because they can be processed using most of the conventional polymer processing methods. PLA is high in strength and modulus, but it is brittle while PBAT is flexible and tough. Thus, PBAT is a good candidate for the toughing of PLA. But when the PLA is blending with PBAT, a certain strength of PLA may be affected. Hence, the reinforcement material is required to improve weakened strength. In this study, PLA was blended with PBAT at various ratios (PLA: PBAT = 90: 10, 80: 20, 70: 30) with a melt‐blending method. The PLA/PBAT blends at a blend ratio of 80: 20, exhibited optimum mechanical performance. Then, PLA/PBAT blends at a blend ratio of 80: 20 was reinforced with different content of EFB-MCC (1 wt%, 3 wt% and 5 wt%) using an internal mixer. The PLA/PBAT blends reinforced with EFB-MCC composites were produced using the compression moulding method. The mechanical, thermal and morphology properties of the composites were investigated. The impact strength of PLA/PBAT blend after addition of both C-MCC and EFB-MCC up to 5 wt% was reduced. The morphological observations from SEM proved the occurrence of the MCC agglomeration in PLA/PBAT blend. DSC results showed trivial changes between the Tg and Tm of PLA/PBAT blend with PLA/PBAT blend reinforced with both types of MCC. TGA results demonstrated that the PLA/PBAT blend reinforced with EFB-MCC has better thermal stability compared to C-MCC. However, further research is needed to improve the interfacial properties of the immiscible PLA/PBAT by compatibilization and enhance the properties of the MCC reinforced PLA/PBAT blend composites.