| Autor: |
Lipatov, Y S, Kosyanchuk, L F, Nesterov, A F |
| Zdroj: |
Polymer International; September 2002, Vol. 51 Issue: 9 p772-780, 9p |
| Abstrakt: |
The in situ formation of blends of two incompatible polymers was studied. The kinetics of simultaneously proceeding reactions of radical polymerization of methyl methacrylate and polyaddition reaction of polyurethane formation was investigated for various ratios of monomeric compounds in the reaction mixture. It was established that the kinetics of formation of each polymer in the mixture depends on the presence of the other and on the kinetics of its formation. These parallel reactions are accompanied by phase separation at a definite conversion degree of each monomer. The onset of phase separation does not affect the course of the kinetic curves. The regularities of phase separation in connection with reaction kinetics were investigated by light scattering. It was found that because of the difference in the rates of the two reactions, the ratio of the polymers formed in the reaction mixture continually changes in time. In spite of this, initial stages of the phase separation may be considered as proceeding according to the spinodal mechanism. Values of amplification factors were calculated which depend on the component ratio and reaction rates. It was established that reaction‐induced phase separation determines the formation of the interconnected morphology immediately after the onset of phase separation, when the composition of the polymer blends has not yet reached its equilibrium value.© 2002 Society of Chemical Industry |
| Databáze: |
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