Fibrillation of Crystallizable Polymers in Flow Exemplified by Melts of Mixtures of Polyoxymethylene and Copolyamides

Abstract

In extrusion (or in extension) of melts of mixtures of a number of polymers, which differ essentially in the rate of crystallization, degree of crystallinity or melting temperature, the rapidly crystallizable component of a mixture forms tens and hundreds of thousands of very thin fibres of practically infinite length, whose diameter depends on the composition of the mixture and the extrusion conditions. This also refers to mixtures of crystallizable and amorphous polymers. After the polymer forming the matrix is extracted with a solvent (from the solidified extrudate) the high-crystalline dispersed component is in the form of a bundle of extremely thin fibres with a diameter less than one micron.