The effect of a shear stress field on the phase and relaxation transitionsin the poly(ethylene oxide)-poly(methyl methacrylate) system

The crystallization and glass transition processes in the PEO-PMMA system u nder static conditions and in a shear stress field were studied by the meth ods of cloud points, viscometry, DSC, X-ray diffraction, and polarization m icroscopy. The temperature-concentration regions of coexistence of the amor phous, crystalline, and glassy polymer blends were determined. Application of the mechanical field results in an increase in the glass transition temp eratures and the PEO crystallization temperatures in the blends. The enthal pies and entropies of the orientational ordering of PEO macromolecules in a sheer field were determined. Variation of the PEO macromolecular size indu ced by deformation of the blends was calculated.