| Abstract: | The internal structure and failure of crazes in linear and long-chain branched poly(styrene) (PS) were investigated by means of in situ transmission electron microscopy (TEM). It was found that long-chain branched PS presents more finely fibrillated up to homogeneous crazes at room temperature instead of the typical fibrillated ones for linear PS. The failure of homogeneous crazes in long-chain branched PS indicates a more ductile behavior than the fibrillated ones. The microhardness of these materials was measured, and it was seen that the hardness value increased with increasing amount of long branches in the PS. In addition, the rate of creep under the indenter (creep constant) for these materials was investigated. The lowest value for the creep constant corresponded to the PS sample with the largest amount of long branches. |
