Impact behavior of microcellular foams of polystyrene and styrene‐acrylonitrile copolymer, and single‐edge‐notched tensile toughness of microcellular foams of polystyrene, styrene‐acrylonitrile copolymer, and palycarbonate

In the first part of this series of papers, the tensile properties of microcellular foams of polystyrene (PS), styrene-acrylonitrile copolymer (SAN), and polycarbonate (PC) were reported. In this part, the impact properties of unnotched, sharply and bluntly notched samples of microcellularly foamed PS and SAN samples were studied. Furthermore, the effects of the sharpness of the notch as well as of the speed of the test were studied by comparing the impact tests with the single-edge-notched (SEN) tensile tests, which were carried out for the PS, SAN, and PC samples. Some limited improvement in impact and SEN tensile properties was exhibited in some experimental conditions. The impact properties of microcellularly foamed PC samples are reported elsewhere.