Journal of Polymer Science Part C Polymer Symposia · 1968 · 30 citations · 1 references
Natural SciencesChemistryMaterials ScienceMaterials ThermodynamicsPolymer ChemistryThermodynamicsGlass MaterialsPolymer CharacterizationPolymer Physical ChemistryPolymer PhysicsPolymer ThermodynamicsGlass FormationGlass TransitionGlass Transition TemperatureGlass Transition ThermodynamicsGlassy StatePolymer Glass TransitionPolymer MeltsPolystyrene
Abstract Samples of fluid polystyrene are converted into the glassy state at 20°C. and 1 atm. pressure by two different routes: ( a ) by cooling at 1 atm. pressure and ( b ) by cooling at 1250 atm. and then decompressing. The heats of solution of the samples are determined in toluene at 30°C. The samples are found to have similar enthalpies, although their densities are different. An attempt is made to explain the results in terms of freezing of rotational isomerism at the glass transition temperature.
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