DYNAMIC-MECHANICAL PROPERTIES OF PEEK, PEI, PES WITH REFERENCE TO THEIR EMPLOYMENT IN THE COMPOSITE FIELD

The dynamic-mechanical behaviour of high performance thermoplastic polymers (PEEK, PEI, PES) and their composites with carbon fibres is presented over a wide temperature range. Secondary transitions are observed at different temperatures in the polymer matrices and tentative interpretation is given of the corresponding relaxation processes. The static and dynamic-mechanical behaviour of unidirectional composites with reference to the fibre direction is discussed. Four elastic constants (E1, E2, G12, G23) are evaluated and the results are compared to existing theoretical models.