<正>A method to quantify crazing deformations by tensile tests for polystyrene （PS） and polyolefin elastomer （POE） blends was investigated. The toughness of PS/POE blends

reflected by the Charpy impact strength

increased with the content of POE. SEM micrographs showed the poor compatibility between PS and POE. In simple tensile tests

it is very easy to achieve the ratio of crazing deformation

i.e. K by measuring the size changes of samples. The K values decreased with increasing the content of POE

and the deformations of PS/POE blends were dominated by crazing. The plots of the change of volume （ΔV） against longitudinal variation （Δl） showed a linear relationship

and the slope of lines decreased with the content of POE. Measuring samples at the tensile velocities of 5 mm/min

50 mm/min

and 500 mm/min respectively

the K values kept unchanged for each PS/POE blends.