Effect of rubber particle size on the impact tensile fracture behavior of MBS resin with a bimodal particle size distribution

We performed impact tensile fracture experiments on methylmethacrylate–butadiene–styrene (MBS) resin with small and large particles in a bimodal size distribution, and examined the effects of particle size on fracture behavior by fixing the total rubber content (28 wt%) and the small particle size (about 140 nm), and varying the size of large particles (about 490 nm or 670 nm). Dynamic load P′ and displacement δ′ of single-edge-cracked specimens were measured using a Piezo sensor and a high-speed extensometer, respectively. A P′−δ′ diagram was used to determine external work U ex applied to the specimen, elastic energy E e stored in the specimen, and fracture energy E f for creating a new fracture surface A s. Energy release rate was then estimated using G f = E f/A s. Values of G f were correlated with fracture loads and mean crack velocity v m determined from load and time relationships. We then examined the effect of particle size on G f and v m, and results indicated that particle size plays an important role in changing the values of G f and v m.