Chlorinated high density polyethylene. II. Solid state structure

Chlorination of high density; polyethylene results in polymers which consist of unmodified methylene units and chlorinated methylene co‐units. The effect of the concentration and distribution of chlorinated units on the solid state structure has been examined by thermal, wide angle X‐ray diffraction and dynamic mechanical analysis. As the substitution becomes more random, the crystallinity, crystallite size, and crystalline perfection decrease for a given chlorine content. The chlorinated units are shown to be capable of co‐crystallizing, and the concentration of chlorine in the crystalline phase increases as the distribution is made more random. Concurrently, the chlorine concentration of the amorphous phase decreases. Segregation of chlorine into the amorphous regions is most efficient when the substitution is blocky.