Glass Transition Of PMMA Research Articles

Glass transition of polymethylmethacrylate at elevated pressures

The glass transition of PMMA at pressures of up to 700 MPa has been studied in the 370–400°K temperature range. Glass point depends on pressure asymptotically with T g being practically independent of pressure above 500 MPa. The results are discussed from the viewpoint of the Gibbs-Di Marzio glass transition theory.

Gas chromatographic determination of the interaction parameter of poly(ethylene oxide)/poly(methyl methacrylate) blends

AbstractInverse gas chromatography (IGC) has been used to investigate thermodynamic miscibility of a molten poly(ethylene oxide) (PEO)/poly(methyl methacrylate) (PMMA) blend. Toluene, benzene, and chloroform have been employed as probes in pure and mixed stationary phases of these polymers. Experimental measurements have been taken over a narrow range of temperatures because of the high PMMA glass transition temperature as well as the degradation of the PEO. The interaction parameter χ23 determined at 150°C is slightly negative and dependent on the interacting probe, as has been also noted in previous chromatographic studies on polymer‐polymer miscibility. The last section is devoted to a model calculation, using Flory's equation of state theory. Different χ23‐concentration curves have been simulated, with the interaction energy parameter X23 as an adjustable parameter.