Morphology Controlling And Properties Of Polypropylene/Glass Fiber Composites Obtained Via Shear Stress Field

In recent years, polymer/fiber composites have been intensively investigated in both industrial and academic fields, because they exhibit unusual and valuable mechanical and thermal properties compared with pure polymers. Within polymer/fiber composites, glass fiber is the most preferred reinforcement material despite its limitations. Most work has been focused on the importance of the chemistry used to modify the surface of the fibers and improving the adhesion between the fiber and the matrix using coupling agents.The morphology controlling of polymer composites during the process is one of the hottest research topics in polymer science and engineering at present. The aim of morphology controlling is to achieve the desired structure via special ways, thus improving the properties of polymer composites.Our purpose in this study was to determine the effect of shear on the fiber orientation and interfacial adhesion in poly (propylene) /glass fiber composites via dynamic packing injection molding (DPIM) , in which the melt is first injected into the mold and then forced to move repeatedly in a chamber by two pistons that move reversibly with the same frequency as the solidification progressively occurs from the mold wall to the molding core part. SEM, TGA, FT-IR, DSC, AFM and mechanical testing were used to characterize the samples obtained.The majority of fibers are aligned parallel to the flow direction along the sample thickness, even at the core, in contrast to the products obtained via conventional injection molding where the orientation of fibers is observed only at the skin. The tensile strength increased significantly when the fibers were aligned...