The segmental and local dynamics of amorphous blends of poly(methyl methacrylate) and polyethylene oxide) (PMMA/PEO) were investigated using dielectric relaxation spectroscopy. The derivative of the dielectric permittivity facilitates the observation of the cooperative segmental relaxation (α b) in blends with low PEO content, which is mostly masked in ∈″ spectra. For blends aged at room temperature, a DSC endotherm gradually develops near the expected PEO T m and shifts to higher temperatures with increasing aging time. However, X-ray diffraction from PEO crystals is not observed, indicating that the glassy blends undergo physical aging at room temperature. A relaxation appears in the blends between the PMMA and PEO local relaxations, which we propose is associated with regions of PEO partial order.
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry