Lightscattering and viscosities measurements of dilute solutions of some Schiff base polymers

Three schiff base polymers polymethylene-bis(salicylaldehyde) tetramethyleth]enediimine (pmsaten). polymethylene-bis(salicylaldehyde)meso- stillbenediimine(meso-pm.sas) and poly-methylene-bis(2-hydroxyacetophenone)1,2- propylenediimine (pmhapn) were prepared and indicated refractive index increments (da/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 an/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 parametcrs as energy of activation (δgv),heat of activation (δhv) and entropy of activation (δsv) of viscous flow were calculated at different temperatures.