Toughening Cyanate Ester Resin by Using Poly(n-butyl acrylate)@Polymethyl Methacrylate Core-Shell Structured Polymer Particles

Aseries of core-shell structured poly(n-butyl acrylate)@poly(methyl methacrylate) (named PBMMA) impact modifiers differing in core/shell weight ratio (60/40, 65/35, 75/25, 70/30, to 80/20) with an average particle size of 346 nm were prepared by seed emulsion polymerization. The toughening effects of the core-shell structured particles with various compositions and under different adding amounts toward cyanate ester (CE) resin were investigated. It was found that the polymerization had a very high instantaneous conversion (90wt%) and overall conversion (95wt%). The PBMMA latexes had an obvious core-shell structure confirmed by transmission electron microscope, and the weight ratio of core/shell had inconspicuous influence on the seed-emulsion polymerization process. The mechanical properties of the PBMMA/CE blends were evaluated, and scanning electron microscope (SEM) was used to observe the fractured surface morphology. We also conducted the dynamic mechanical analysis by which the molecular movement of the CE/PBMMA blends could be revealed. The results showed that PBMMA can be dispersed well in the matrix, and the brittle-ductile transition point emerges under an appropriate value of the core-shell weight ratio (60/40) and the adding amount of the core-shell structured particles (5wt%). As a result, the PBMMA/CE blend was determined to have a high impact strength which is 3.78 times of pure CE resin. The mechanical properties agreed well with the SEM observation. © 2019, Materials Review Magazine. All right reserved.