Control of Phase Structure in Polymer Blends.

摘要

Polymer blending is presently in a state of rapid scientific and commercial development. Another related physical approach is polymer-polymer composites in the form of fibers, film, and sheet materials often made via co-extrusion technology. Polymer blends can be divided into two major classes based on their thermodynamic phase behavior. Miscible blends are homogeneous to the polymer segmental level and a major factor is the energetics of segmental interaction. The first section outlines some of the incentives for polymer blending and gives examples of the types of problems that can be solved by this route. In every case, the property relationships for blends depend critically on control of phase structure. Therefore, subsequent sections will deal with some of the important scientific issues in this area. The first of these is the selection or design of components when a homogeneous or miscible mixture is needed. The second involves phase separated systems where improved interfacial adhesion and morphological control are required, i.e., the concept of (compatibilization). Copolymerization into random, block, or graft structures is shown to be a powerful way of dealing with these problems. (aw)