Microstructure and mechanical properties of aminated polystyrene spheres/epoxy polymer blends

Polystyrene (PS) spheres were chosen as soft fillers to toughen epoxy polymer. In order to weaken the aggregation of PS spheres in epoxy matrix caused by phase separation, amination treatment were firstly done on them. The results of FTIR, zeta potential test and TGA indicate that amine groups have been successfully grafted to the surface of PS spheres. SEM observation suggests that aminated PS spheres are monodisperse in prepared epoxy blends. The tensile strength and fracture toughness of the 15 wt% aminated PS spheres/epoxy polymer blends are 74.5 MPa and 2.23 MPa m1/2. Compared with cured pure epoxy polymer, they are increased by 25.6% and 84.3%, respectively. Excellent dispersion properties in epoxy matrix and increased interfacial force with epoxy matrix are responsible for the huge effect of the aminated PS spheres on toughening epoxy polymer.