Non-isothermal crystallization kinetics of poly(lactic acid) (PLA) composites consisting of hemp fiber and nanosilica plasticized with tributyl citrate (TBC) was studied by differential scanning calorimetry (DSC) at various scanning rate. Polarized optical microscopy (POM) is performed as a complementary study of crystal growth in PLA crystallization. The aim of this research was to investigates the non-isothermal crystallization kinetics of plasticized PLA composites and further elucidates with Avrami and Ozawa models to investigate the nucleation activity and crystal growth of PLA composites. DSC showed that TBC in PLA composites enhanced nucleating ability of fillers and crystal growth, attributed to increased PLA chain mobility. PLA crystallized in the range between the glass transition temperature and melting temperature of neat PLA. Addition of TBC in PLA composites slightly increased the crystallinity, consisted of the same crystalline modification of PLA matrix. Hemp and nanosilica effectively acted as heterogeneous nucleation agents for PLA that promoted the nucleation and consequently increased the crystallization rate. POM revealed that the crystal morphology under isothermal conditions was modified by silica, hemp or both suggesting changes in nucleation. The selected plasticizer and reinforcing agents showed promising results in improving the crystallization of PLA composites.
Volume 12 | 02-Special Issue
Pages: 701-708
DOI: 10.5373/JARDCS/V12SP2/SP20201123