Solvent effects on the theta temperature of polymers of various architectures

Abstract

The solution conformational properties of polymer chains of various architectures are studied, taking the effects of the solvent into consideration. The usual treatment of polymers in solution in which the solvent is considered as a uniform medium influencing the interactions between the polymeric units in an average way is extended in order for the effects of the solvent to be considered in more detail. The state with the solvent as an average medium is taken as the zeroth-order problem. The effects of the solvent molecules beyond this are conceived in the statistical-mechanical treatment of the problem through the inclusion of the vacancies of the medium produced from the presence of the macromolecules. First-order calculations in the density of vacancies yield correctly the theta temperature changes of polymers of various architectures.