Abstract:
Three Schiff base polymers polymethylene-bis(salicylaldehyde)tetramethylethlene-diimine (PMSATen), polymethylene-bis(salicylaldehyde)meso-stillbenediimine(meso-PMSAS) and poly-methylene-bis(2-hydroxyacetophenone)1,2-propylenediimine (PMHAPn) were prepared and indicated refractive index increments (dn/dc) within 0.223-0.241 at 436 nm and 0.155-0.130 at 546 nm. The data for dn/dc was obtained by extrapolating intercept of plot △n/c against concentration to zero concentration. The values of Hc/τ (τ = turbidity) were plotted against concentration and reciprocal of the intercept at zero concentration gave the molecular weight in the range of 58100-66890.The polymers were examined for reduced, intrinsic, inherent and absolute viscosities. Thermodynamic parameters as energy of activation (△Gv), heat of activation (△Hv) and entropy of activation (△Sv) of viscous flow were calculated at different temperatures.
