Transforming polymer blends into composites: a pathway towards nanostructured materials

Abstract

Polymer blends and polymer-based composites are two of the most rapidly developing groups of materials being of industrial, as well as of academic, interest. More than a decade ago a new group of polymer materials was introduced, which became known under the name 'microfibrilar composites' (MFCs). They were obtained by the transformation of blends of thermoplastic polymers into micro-or nanostructured systems by combination of appropriate mechanical and thermal treatments. Since then, the importance of these novel materials, both for theory and for engineering practice, has increased significantly. It is an objective of this review to outline the place of MFCs within the whole variety of polymer-based composites. Furthermore, the methods of their preparation, the ways of investigating their structure and the relation of the structure and mechanical properties are discussed. Ultimately, an evaluation of the future trends in this exiting interdisciplinary research field is attempted.

Preparation, structural development, and mechanical properties of microfibrillar composite materials based on polyethylene/polyamide 6 oriented blends

“…5 There are a number of publications on MFC processing, properties, and morphology. 6 In the first studies, the composites were prepared on a laboratory scale, with every one of the three processing stages performed separately, one after another. [1][2][3][7][8][9][10][11] This discontinuous scheme is difficult to apply in largescale production.…”

Nanostructure Evolution Mechanisms During Slow Load‐Cycling of Oriented HDPE/PA Microfibrillar Blends as a Function of Composition

“…Low ash content is a European legislative request [4][5][6] that must be met in the future. Microfibrillar reinforced composites (MFC) are polymerpolymer composites made from thermodynamically immiscible polymers in which both the isotropic matrix and the fibrous anisotropic reinforcements are formed in-situ during processing [7,8] . The fabrication of MFCs begins with the melt-blending followed by cold-drawing.…”

“…A third haul-off unit has applied the last drawing causing the diameter of the strand to decrease from 2 mm (at the die outlet) to about 0.6-0.9 mm. Details concerning the principle of the preparation of the HDPE/PA/YP precursors [8] and the design of the extruder line [20] have been published previously. …”

X‐Ray Scattering Studies on Multiphasic Polymer Systems

“…To perform the matrix isotropization stage, these strands are further processed by compression molding at temperatures above T m of the matrix and below T m of the reinforcing fibrils, whereby the former melts assuming the form of the mold and embedding the bundles of oriented fibrils whose orientation and length may be varied [27].…”