TY  - EJOU
AU  - Srithep, Yottha 
AU  - Veang-in, Onpreeya 
AU  - Pholharn, Dutchanee 
AU  - Turng, Lih-Sheng 
AU  - Morris, John 

TI  - Improving Polylactide Toughness by Plasticizing with Low Molecular Weight Polylactide-Poly(Butylene Succinate) Copolymer
T2  - Journal of Renewable Materials

PY  - 2021
VL  - 9
IS  - 7
SN  - 2164-6341

AB  - A low-molecular-weight polylactide-poly(butylene succinate) (PLA-PBS) copolymer was synthesized and incorporated into polylactide (PLA) as a novel toughening agent by solvent casting. The copolymer had the same chemical structure and function as PLA and it was used as a plasticizer to PLA. The copolymer was blended with PLA at a weight ratio from 2 to 10 wt%. Phase separation between PLA and PLA-PBS was not observed from their scanning electron microscopy (SEM) images and the crystal structure of PLA almost remained unchanged based on the X-ray diffraction (XRD) measurement. The melt flow index (MFI) of the blends was higher as the amount of PLA-PBS increased, indicating that the block copolymer did improve the mobility of the PLA chains. Moreover, tensile tests revealed that PLA with greater PLA-PBS copolymer exhibited higher elongation at break and it reached the maximum at 8 wt% of PLA-PBS in PLA, which was around 6 times higher than that of pure PLA. Furthermore, the glass transition temperature, measured by differential scanning calorimetry (DSC), markedly decreased with an increasing amount of the copolymer as it decreased from 61.2°C for pure PLA to 41.3°C when it was blended with 10 wt% PLA-PBS copolymer. Therefore, the PLA-PBS copolymer was shown to be a promising plasticizer for fully biobased and toughened PLA.
KW  - Polylactide; poly (butylene succinate); low molecular weight copolymer; biodegradability; plasticizer

DO  - 10.32604/jrm.2021.015604