Acrylonitrile-styrene–acrylate@ silicone three layers core-shell nanostructure copolymer with excellent impact toughness and highness-strength balance

Due to its excellent weather resistance, acrylonitrile-styrene-acrylate (ASA) resin is widely utilized. However, one critical challenge is its unsatisfactory impact property, which restricts its further application. Although various studies have been reported on improving the toughening effect of ASA resin, most of them reduce its strength and modulus. It is difficult to strike a balance between the improved toughening effect and the reduced strength and modulus. Herein, we designed a silicone rubber filled acrylate core to synthesize an acrylonitrile-styrene–acrylate@ silicone (Si-ASA) three-layer core-shell nanostructure copolymer via three-step emulsion polymerization. Introducing ductile silicone rubber into the interior of acrylate rubber microparticles can increase and refine the cavitation of the rubber layer upon impact. Meanwhile, the fibrillation of silicone cores can absorb impact energy and bridge cracks. SEM images demonstrated the formation of the three-layer nanostructure of Si-ASA. The mechanical property results showed that the prepared Si-ASA exhibits a significantly increased impact strength of approximately 19.5KJ/m 2 , which is nearly twice that of the commercial ASA. Considering the much higher impact property of Si-ASA, this slightly higher of modulus is significant. These indicate that the Si-ASA three-layer core-shell nanostructure copolymer, when applied to ASA resin helps in achieving rigid-tough balanced materials.