BLENDS OF POLY(ETHYLENE OXIDE) POLY(METHYL METHACRYLATE) - AN IR AND NMR-STUDY

I.r. and high-resolution solid-state C-13 n.m.r. spectra, as well as p roton relaxation times T-1(H) and T-1 rho(H) of poly(ethylene oxide) ( PEO)/atactic poly(methyl methacrylate) (a-PMMA) blends in the solid st ate, with PEO weight fractions of 10, 30, 50 and 70% were measured. In fra-red spectra of pure PEO with various molecular weights were also m easured. The measurements indicate that no large changes in the conten t of the ttt conformational structure of PEO with blending occur. In t he blends containing 30% PEO or less, only a negligible amount of crys talline PEO has been found. From the T-1(H) and T-1 rho(H) relaxation times it follows that all the blends studied are completely homogeneou s on the scale of 20-70 nm; at the same time at least part of the PMMA and PEO chains are intimately mixed in the amorphous phase with the a verage size of the PMMA domains being below 6 nm, T-1(H) values and C- 13 n.m.r. linewidths indicate changes in the mobility of polymer segme nts with blending.