The synthesis, characterization of opal-poly(methyl methacrylate) graft polymer based on ICAR-ATRP and its effect on performance of poly (lactic acid)

Abstract

ABSTRACT In this work, initiators for continuous activator regeneration atom transfer radical polymerization was adopted to synthesize opal-poly(methyl methacrylate) graft polymer (opal-PMMA) with methyl methacrylate as monomer. The optimum reaction conditions obtained from orthogonal experiment were as follows: a ratio between ethyl-2-bromoisobutyrate and 2,2ʹ-azobis(2-methylpropionitrile) of 1.5: 60 (mL: mg), reaction time of 9 h, the ratio between FeCl3·6H2O and triphenyl phosphine of 40: 40 (mg: mg) and reaction temperature of 80 °C. The structure of opal-PMMA was characterized by Fourier transform infrared spectroscopy combined with the water contact angles measurement and X-ray photoelectron spectrometer. Furthermore, poly (lactic acid) (PLA)/opal-PMMA composites were prepared by melt blending at different loading levels of opal-PMMA. In addition, the performance, crystallization, and thermal decomposition kinetics of PLA/opal-PMMA composites were studied. Especially, when 0.3 wt% opal-PMMA was added, the impact strength of PLA/opal-PMMA composites was improved by 192% and its crystallinity increased from 9.01% (PLA0) to 35.55%. Meanwhile, thermal decomposition kinetics indicated that opal-PMMA effectively improved the thermal stability of PLA bulk. Rheological test demonstrated that opal-PMMA enhanced the systematical rigidity of PLA compared with the pristine PLA, which could ascribe to the uniform dispersion of opal-PMMA and more entanglement points with PLA molecular.