Physicochemical characteristics of fabrication of fibers from mixtures of polyacrylonitrile-based polymers

Abstract

The physicochemical principles of fabrication of fibers from mixtures of PAN-based polymers via a common solvent were investigated. The effect of the added polymers on mass exchange and phase separation dynamics was demonstrated. The effect of coprecipitation of the components of stable polymer pairs and separate precipitation of unstable polymer blends from solution was established. The capacity of fibers from polymer blends for orientational drawing and the effect of orientation of the structural elements are determined by the concentration of residual solvent in the fiber, the plasticizing effect, flexibility, and phase state of the added polymers. A quantitative correlation was established between the structure and composition of fibers from polymer blends. A homogeneous (for stable systems) or microheterogeneous (for unstable systems) structure of the fibers is formed with a low concentration of polymer added to PAN. Heterogeneous overall supermolecular (for stable systems) or laminar (for unstable systems) structures occur with a high concentration of the second component. Different supermolecular structures are formed and different physicomechanical properties are obtained as a function of the nature and amount of added polymers and the conditions of fabrication of the fibers.