Pultrusion process development of a graphite reinforced polyetherimide thermoplastic composite

High performance thermoplastic polymers do not contain reactants and solvents able to react with a pultrusion die to yield polymerization; consolidation is therefore performed with a rigid or a boardy prepreg, and consolidation must occur with polymers whose viscosities are of the order of 1 million centipoises or more. Die temperatures are typically above 400 C, by comparison with the 150-200 C encountered in thermosets. A methodical approach is presented here for the development of a pultrusion process suitable for polyetherimide and other engineering thermoplastics, employing SEM, DSC, TGA, and ultrasonic C-scanning.