Modification of stress-strain behaviour in aromatic polybenzoxazines using core shell rubbers

2,2-Bis(3,4-dihydro-3-phenyl-2H-1,3-benzoxazine)propane is blended with a core shell rubber (CSR), with a siloxane core and an acrylic shell. SEM-EDX analysis reveals an even distribution with good cohesion between the resin and CSR particles. Addition of CSR raises glass transition temperature, thermal stability (in a linear fashion) and improves strain behaviour, although there is a penalty in tensile strength and Young's modulus. Rubber cavitation is the principal toughening mechanism.