Miscbility and phase separation in polymer blends
The phase behaviour of polymer blends in the systems; homopolymer/homopolymer, homopolymer/randomcopolymer and random copolymer/random copolymer has been characterized. Systems containing random copolymers generalny tend to phase seperation at elevated temperatur es (LSCT behaviour). Experimental determination of miscibility are as as a function of temperature and copolymer composition provides the interaction parameters necessary for theoretical explanations and predictions of various phase separation phenomena. Just above the LCST polymer blends exhibit regular,highly interconnected two-phase morphologies. The rate of decay of these structures and of the formation of irregular two-phase structures is estimated. The phase separation kinetics is discussed in terms of Cahn's linearized theory.It can be show that the linear theory adequately describes the elary stages of phase decomposition. This theory is applicable to the reverse phenomenon, the phase dissolution below LCST. Unlike the case of phase separation, the difusion-controlled regime is that in the late stage of chase dissolution.
If you are interested in full versions of articles, please contact the editorial team of email@example.com