STRUCTURE AND ADHESIVE PROPERTIES OF EPOXY-RESINS MODIFIED WITH ACRYLIC PARTICLES

The morphology and physical properties of dicyandiamide (DICY)-cured e poxy resin modified with acrylic particles were studied. We used one h omopolymer of methyl methacrylate (MMA) and three copolymers of MMA an d glycidyl methacrylate (GMA) [P(MMA-GMA)] containing different amount s of GMA as the acrylic particles. When a mixture of the acrylic parti cles and the epoxy resin was heated, the particles were swollen with t he epoxy resin and thus a soft gel with no fluidity was formed. Furthe r heating to the reaction temperature of the DICY cured the soft gel. The structure of the acrylic particles strongly affected the physical properties of the soft gel and the cured epoxy resin. The cured system containing 5 mol% of GMA showed the best physical properties (impact strength and adhesive property), but there was a tendency for the phys ical properties to decline with a higher GMA content. We have determin ed that the GMA content of the acrylic particles affects the concentra tion of network chains in the system.