碳酸钙晶须增强聚醚醚酮自润滑复合材料的动态力学行为研究

BSTRACT：The composite blocks of polyetheretherketone(PEEK) filled with different content of calcium carbonate (CaCO3) whisker and polytetrafluoroethylene(PTFE) were prepared by compression molding. Dynamic mechanical thermal analysis(DMTA) was performed on PEEK composites in order to investigate thermally activated molecular relaxation processes and their impact on mechanical properties. Dynamic modulus and mechanical loss factor ( tanθ) were continuously measured during a DMTA thermoscan carried out within the temperature range of 25℃~300℃. The selected test configuration and operating mode were, respectisely, single cantilever stretching and constant-amplitude forced flexuraloscillation. The analysis shows that all materials show a large change in storage modulus at the glass transition temperature(Tg). CaCO3 whisker exhibits an significant effect on the dynamic stiffness at low and high temperatures. The increase of whisker content contributes to a rise to the storage modulus. These modulus of CaCO3 whisker filled PEEK composites are larger than those observed for pure PEEK, especially below Tg. Inclusion of PTFE closely related to tribological behaviors, the storage modulus of CaCO3/PEEK are deduced below Tg，while Tg and the storage modulus above Tg do not change much . These increases in the thermal mechanical properties are conformed to the better tribological behaviors of the filled PEEK self-lubricating composites.