| Abstract: | Fulvic acid–thiourea amide derivates (FA‐T) was synthesized via amidation with FA and thiourea, and its optimum reaction conditions were 7 h of reaction time, 1 wt% of sodium methylate, 130°C of reaction temperature, and 2 g of thiourea. Then, FA‐T grafted polystyrene (FA‐T‐PS) was synthesized by activators generated by electron transfer for atom transfer radical polymerization. Fourier transform infrared spectroscopy, static contact angle analysis, and X‐ray photoelectron spectroscopy confirmed that the synthesis of FA‐T‐PS. Then, poly(lactic acid)/FA‐T‐PS(PLA/FA‐T‐PS) composites were prepared by the melt blending with FA‐T‐PS as fillers. Mechanical test demonstrated that FA‐T‐PS increased the flexibility and ductility of PLA composites. Dynamic mechanical analysis revealed that FA‐T‐PS reduced friction and loss between PLA chain and filler, and further reformed had higher interfacial compatibility with PLA. Differential scanning calorimetric results and polarized optical microscopy analysis displayed that FA‐T‐PS had strong heterogeneous nucleation effect, which effectively enhanced the crystallization rate and the crystallinity of PLA. Friedman thermal decomposition kinetics presented that E a of PLA/FA‐T‐PS (0.3 wt%) was increased by 52.94% compared with PLA, which demonstrated that FA‐T‐PS significantly enhanced the thermal stability of PLA. Therefore, FA‐T‐PS effectively improved the comprehensive performance of PLA. POLYM. ENG. SCI., 59:1787–1798, 2019. © 2019 Society of Plastics Engineers |
