The Effects of Crystallinity on the Mechanical Properties of PEEK Polymer and Graphite Fiber Reinforced PEEK

Abstract

The mechanical properties of PEEK 150P polymer and APC-2 graphite/PEEK com posite were measured at different crystallinities, from 0 to 40 weight percent. For PEEK 150P the tensile, compressive, and shear properties and the fracture toughness were measured. For APC-2 the mode I and mode II fracture toughnesses and fracture energies as well as the mixed mode stress intensity factors were determined. Expressions are pre sented relating the mechanical properties to crystallinity. Finally, data are given which compare the mechanical properties of materials in which the same crystallinity was estab lished by different thermal processes.