Influence from the Temperature on the Mechanical Behavior of Pei/Glass Fiber Composites

Polymeric composites have been used due to the technological progress in industries, mainly the aerospace. These advances are aimed at obtaining composites with low specific gravity associated with high mechanical properties and stiffness. The main advantages of thermoplastics over thermoset laminates include: fast processing due to the absence of a cure cycle, low moisture absorption, excellent chemical resistance higher service temperature; low costs of transport and storage, higher impact resistance; higher stiffness and possibility of recycling. It is therefore important to investigate the mechanical properties at high temperatures since these materials are subjected to large temperature variations in aeronautical applications. This work is aimed at evaluating the mechanical properties (tensile, fatigue and interlaminar shear behavior) of PEI reinforced with glass fiber at 25 and 80 degrees C. The tensile, shear and fatigue stresses for PEI/glass fiber were found to be higher than in epoxy/glass fiber laminates. However, in all cases a significant deterioration in the mechanical properties was observed at 80 degrees C in comparison to those at room temperature.