Fracture energy and surface topology in the cracking of high performance sulphone polymers

Abstract

The dynamic mechanical properties and the fracture behaviour of three sulphone polymers that offer high temperature capability have been studied. Torsion pendulum analysis was performed over the temperature range −150 to 225° C. Fracture tests were carried out using compact tension specimens and standard Izod impact specimens. It was found that the incorporation of additional groups in the backbone of the sulphone polymer introduced additonal low-temperature relaxation peaks in the dynamic mechanical loss curve and improved polymer fracture energy. The fracture energy of the sulphone polymers was also found to decrease as the loading rate was increased during fracture. The results of post-failure fractography are discussed.