Rubber concentration, impact energy

The three types of force-time behavior noted for HiPS fractured at different temperatures also apply to other polymer blends and grafts, where values of the impact strength (or fracture energy) were measured as a function of temperature. Such behavior has been observed by Bucknall and Street (1967) not only for ABS (Figure 3.17), but also for rubber-modified PVC, HiPS, and a methacrylate-butadiene-styrene (MBS) copolymer. Not surprisingly, the concentration of rubber is important with respect to both the absolute value of impact strength (Figures 3.16 and 3.17) and the type... 

Toughened Polymers with Semicrystalline Matrix. It is well known that toughness of semicrystalline polymers such as PA (polyamide) and PP can be increased similar to the amorphous poljuners by the addition of relatively small amounts of rubber particles such as EPR or EPDM. As in HIPS and ABS, the modifier particles act as stress concentrators, initiating a plastic deformation of matrix strands between the particles as the main energy absorption step. In impact-modified PA and PP at room temperature, plastic deformation takes place through shear deformation (mechanism of multiple shear deformation). 

---