Thermal effects of interaction between macronet isoporous styrene polymers and solvents or precipitators for linear polystyrene

A study has been made of the heats of swelling of macronet isoporous polymers of styrene in toluene and methanol. The swelling of hypercrosslinked networks (degree of crosslinking ≥40%) is shown to be accompanied by liberation of large amounts of heat: 30 and 25 cal/g, respectively. The small difference in the heats of swelling in these media is indicative of small differences in the energy of dispersional interactions of exposed polystyrene chains with “good” and “poor” solvents. This conclusion is corroborated by calculations of the free energy of interaction between hypercrosslinked networks and organic solvents from the isotherms of sorption of their vapors. ΔG reaches high values (500–600 cal/mol) independently of the solvent nature.