Thermodynamics of mixing polymers

Autor: I.M. Sharova, Yu.S. Bessonov, A.A. Tager, L.V. Adamova, T.I. Sholokhovich
Rok vydání: 1975
Předmět:
Zdroj: Polymer Science U.S.S.R.. 17:3178-3187
ISSN: 0032-3950
DOI: 10.1016/0032-3950(75)90350-0
Popis: Free energies Δg x , enthalpies Δh x and entropies TΔs x of mixing were calculated for eight polymer-polymer systems. It was shown that the polymer compositions studied, in respect of the shape of the curve showing the concentration dependence Δg x , may be classified in three groups: stable, metastable and unstable. For a stable cellulose nitrate-polyvinylacetate system a reduction in entropy was observed during mixing, which may be due to ordering of elements of the system. For metastable systems thermodynamic functions of mixing Δh x and TΔs x are positive in one range of composition and negative in the other. An unstable polymethylmethacrylate-polybutylmethacrylate system undergoes endothermic mixing over the entire range of composition and the free energy varies positively and entropy of mixing increases in this case.
Databáze: OpenAIRE