Poly(lactic acid)/opal-methacryloylpropyltrimethoxysilane-polystyrene graft polymer composites: preparation, characterization, and performance

Abstract

Opal-methacryloylpropyltrimethoxysilane-polystyrene graft polymer (opal-MPS-PS) was synthesized using coupling method and solution polymerization. The results of orthogonal experiments showed optimum reaction conditions including: polymerization time of 4 h, catalyst at 0.03 g, reaction temperature of 80 °C, and styrene volume of 4 mL. Moreover, the structure of opal-MPS-PS was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. The results demonstrated that PS was grafted onto opal-MPS. Furthermore, poly(lactic acid) composites (PLA/opal-MPS-PS) were prepared using opal-MPS-PS as filler by melt blending. The results of mechanical testing showed that the impact toughness of PLA/opal-MPS-PS composites was increased by 50.5%. The rheological behavior and morphological analysis showed that PLA displayed high interfacial compatibility with opal-MPS-PS. The polarized optical microscopic and differential scanning calorimetric results showed that opal-MPS-PS with heterogeneous nucleation effect improved the crystallization properties of PLA, and enhanced toughness of PLA. The flame retardancy test showed that the thermal stability and flame retardancy of the PLA composites material were improved compared with PLA. Enzymatic degradation tests showed that opal-MPS-PS had an inhibitory effect on the degradation of PLA. In all, this study provides a promising method to improve the comprehensive performance of PLA through organic modification using opal as filler.