Effect of ambient temperature on mechanical properties of polycarbonate

Abstract

The influences of ambient temperature on mechanical properties of polycarbonate（PC）were investigated. The results show that both tensile properties and flexural properties of PC decrease linearly with the increase of ambient temperature, and the linear correlation is good. When the ambient temperature rises from –40℃ to 130 ℃, the tensile yield stress of PC decreases by nearly 55% and the yield strain decreases by about 63%. When the ambient temperature rises from –70℃ to 130℃, the flexural strength of PC decreases by about 66% and the flexural modulus decreases by about 37%. In addition, the fracture morphology indicates that all tensile fractures at different temperatures originate from the surface of PC, and there are obvious mirror areas, fog areas and rough areas on the fracture surface. The fracture mode of PC changes from rapid brittle fracture at low temperature to ductile fracture at high temperature. However, the impact strength of PC increases first, then decreases and then increases with the increase of ambient temperature. The impact fracture mechanism of PC has a large degree of temperature difference. In the whole range of –40-145 ℃, the impact fracture morphology of PC shows a series of changes from fog zone to sawtooth zone, then to mirror zone, and finally softening and melting.

Keywords

• ambient temperature
• polycarbonate
• mechanical properties
• fracture morphology