Abstract
The effects of the length of glass fibers on the toughness of long glass fiber reinforced polyphenylene sulfide (PPS) composites (PPS-LFT), made by the pulltrusion process, were studied with regards to both the molding V notched specimen and the cutting V notched specimen. Toughness was excellent on the molding V notched specimen. By observing the fracture morphology of the molded V notched specimen, it was found that a crack was formed, due to a slip or debonding at the fiber surface. The crack was propagated along the fiber, due to the pulling out of fibers from the matrix polymer. Both the maximum load and the fracture energy increased with increasing length of the glass fiber, because the resistance created by pulling out the fibers increased with increasing fiber length. In the case of PPS-LFT, it is understood that toughness improved because the slip between the fiber and the resin occurs before the excessive elastic strain energy is stored.