Homopolymer-Copolymer and Copolymer-Copolymer Blends
R. P. Kambour et al. have explained the miscibility of systems by the effects of repulsion between comonomeric units in copolymer chain. It was also discovered that in homopolymer mixtures with copolymers, the transition from miscibility to immiscibility occurs very rapidly even at small change of the copolymer composition. It was shown that the “inner repulsion” between monomeric units in copolymer may prevail over intermolecular attraction between monomeric units of homopolymer and copolymer and determine the miscibility. The greater non-similarity of two monomeric units in copolymer favors the hyperbolic shape of the miscibility border. The energy of interaction between monomeric units of copolymer and homopolymer is mediated by the surrounding of chemically bound structure units of copolymer. Besides mixtures of homopolymer with copolymers and copolymer mixtures, the miscibility windows have been observed also for the mixtures of homopolymers with homologue series of polymers of various chemical nature.