DEVELOPMENT OF CORE-SHELL RUBBER TOUGHENERS

The toughening of thermoset resins is vital to overcome their inherent brittle nature and allow for practical use as engineering resins. Recent applications of thermoset resins as automotive adhesives, electronic encapsulants and matrices for high strength carbon fiber composites require new toughening solutions. The thermoset resin industry has moved towards using these core-shell copolymers (CSRs, core-shell rubbers) as tougheners; however, traditional CSRs are mostly compounded in thermoplastics via extrusion under high shear rates. These additives are considerably more difficult to disperse in liquid thermoset resins using stirred agitation. This work details the results of investigations into polymer composition, isolation method and dispersion process to allow easy dispersion of the newly designed additives. These new materials have been added to thermoset formulations and the mechanical properties characterized. Comparisons to competitive materials and alternative toughening technologies have been made and have shown the new materials to be on par or better than incumbent materials.