Preparation of Impact Modified Epoxy Resin by Using Poly(Butyl Acrylate)/Poly(Glycidyl Methacrylate) Core-Shell Composite Particles

Poly(butyl acrylate)/poly(glycidyl methacrylate) core-shell latex was prepared by a two stage consecutive emulsion polymerization. It was possible to get narrow and monodispersed particles with an increase of shell thickness. This was done by changing the stage ratio of core to shell. The formation of core-shell morphology was confirmed by contact angle measurements, using the characteristics of composite particles e.g., surface tension, surface dispersity, and surface polarity in our research. At low stage ratio of core to shell, the morphology showed a tendency toward not forming core-shell morphology because of the thermodynamic instability, especially the effect of phase volume. The blend of poly(butyl acrylate/poly- (glycidyl methacrylate) core-shell composite particles with epoxy resin showed an impact strength increment of about 1.6 times compared with that of epoxy resin itself. In the toughening mechanism, it was assumed that the crazing effect is preferred to shear banding understanding poly(butyl acrylate)/poly(glycidyl methacrylate) core-shell composite particles as an impact modifier for epoxy resins.