Abstract
Solutions of polyethylene macromolecules immersed in benzene were modeled with self-consistent polymer reference interaction site model (PRISM) theory. The PRISM integral equations for the solution were solved self-consistently for the polyethylene intramolecular chain structure and intermolecular polymer and solvent correlations at various mole fractions. We found that explicitly considering the solvent molecules leads to considerably more short-range structure in the radial distribution function of the polymer, relative to the polymer without solvent at the same concentration. The long-range intermolecular correlations between polymer sites in the correlation hole regime decreased inversely with the polymer concentration as expected. The solvent/solvent radial distribution function, however, showed unexpected changes in shape and intensity as the polymer concentration increased. By using the direct correlation functions from PRISM theory, along with the random phase approximation, we estimated the spinodal temperatures as a function of polymer concentration. PRISM theory, which includes compressibility and nonrandom mixing effects, predicted a significantly higher critical temperature than was obtained from the corresponding incompressible Flory−Huggins theory. The PRISM spinodal curves were in reasonable agreement with experimental dissolution temperatures for octacosane in benzene.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.