NANOSECOND DYNAMICS OF THE MACROMOLECULES OF METHYLCELLULOSE IN SOLUTIONS AND GELS

Cooperative increase of relaxation times that describe nanosecond mobi lity of the polymer chains of methylcellulose in water on heating to 6 0 degrees C was studied by polarized luminescence. The position of thi s cooperative variation of relaxation times on the temperature scale i s controlled by the concentration of polymer in solution (from 0.25 to 10-15 mg/ml). As the concentration is raised to the point of gelation , the growth becomes slower; this is related to the changes in the str ucture of supermolecular aggregates and the formation of quasi-equilib rium elements of the cross-linked structure. Large values of relaxatio n times are retained when an aqueous solution of methylcellulose is co oled from 60 to 40-30 degrees C. In organic solvents (DMF, DMAA), the values of relaxation times decrease on heating. This suggests that hyd rophobic interactions play an important role in the formation of super molecular aggregates in aqueous solutions.