Short fiber reinforced thermoplastic blends

The present thesis investigates the potential of short fiber reinforced thermoplastic blends, a combination of an immiscible polymer blend and a short fiber reinforced composite, to integrate the easy processing solutions available for short fiber reinforced composites with the high mechanical performance of continuous fiber reinforced composites. The focus of the thesis is to develop an understanding of the processes controlling the morphology and the performance of these complex, ternary systems. Depending on the aspect ratio of the filler particles and their compatibility to the polymeric components one can achieve different morphologies, e.g. filler contained within the dispersed phase, within the matrix phase or at the interface between the two phases. If the fibers are sufficiently long and are preferentially wetted by the dispersed phase an effectively continuous network comprised of fibers welded together by the dispersed phase can be created. In such manner a pseudo-continuous fibrous reinforcement is spontaneously formed during the processing step and a composite material with better mechanical performance can be obtained.Applied Science