Publication

Abstract : Microfibrillar composites (MFCs) are novel type of materials in which the reinforcing elements are polymer microfibrils of one or more homopolymers distributed anisotropically in an isotropic polymer matrix. The conspicuous feature of these types of composites is that both the matrix and the reinforcing phase are constituted by thermoplastic materials, which form partners to produce immiscible, fiber forming crystallizable microfibrillar blends (MFBs). Considering the size of the reinforcing elements, MFCs have an intermediate position between conventional fiber reinforced composites and molecular composites. In these types of blends, the required properties could be achieved by the careful selection of the component polymers (matrix and reinforcing elements) and their blend ratios. Fakirov, Evstatiev and coworkers [1–10] reported the pioneering work on this new type of polymeric materials. They made use of this technique: melt blending by extrusion, fibrillization of the blends by zone drawing and isotropization by annealing between the melting temperatures of the polymers involved to prepare polymer-polymer composites. Later on, Fakirov [11] introduced the concept of extrusion, on line drawing and isotropization using compression or injection molding to prepare MFCs. This technique was then used by several research groups [12–17] with their own variations in the drawing methodology adopted...