The Frenkel-Flory-Rehner (FFR) hypothesis that the elastic free energy of a swollen network is balanced by the free energy of mixing has been examined using experiments on dicumyl peroxide crosslinked natural rubber. Swelling was performed in good (benzene) and poor solvent (methyl ethyl ketone, ethyl acetate, acetone) conditions. Crosslink density varied from 2.1×10-5 to 3.0×10-4 mol cm-3. It was found that consistency of the FFR hypothesis with experiment requires the Flory-Huggins X parameter to be dependent upon the crosslink density, ν. An apparently universal relation between the value of Xeff and crosslink density, ν, is proposed. For the natural rubber and solvents studied α appears to be independent of solvent.
|Number of pages||4|
|Journal||Polymer communications Guildford|
|State||Published - Sep 1988|