MOLECULAR CHARACTERIZATION OF WATER-SOLUBLE, CATIONIC POLYELECTROLYTES

rylamide-co-[2-(acryloyloxy)ethyltrimethylammonium chloride]} (1), mid e-co-[2-(methacryloyloxy)ethyltrimethylammonium chloride]} (2) and lam ide-co-[3(acryloylamino)propyltrimethylammonium chloride]} (3) with ca tionic monomeric unit mole fractions of 8, 25, and 50 mol-%, and the c orresponding homopolymers were characterized with respect to their mol ecular dimensions in 1 M sodium chloride solution at 25-degrees-C in t he molecular weight range from 200000 to 16000000, using light-scatter ing and viscometric measurements. It was possible to establish correla tions between molecular weight, intrinsic viscosity and radius of gyra tion. Whereas a steady increase in the exponents of the [eta] vs. M- a nd [R(G)2]0,5 vs. M-relationships can be observed with increasing char ge density, there is an initial decrease in the values of the exponent s for 2 and 3, when 8 mol-% of the cationic monomer is inserted into p olyacrylamide. If the charge density is increased further, these value s can also be seen to rise steadily. The findings are explained by the different structures in solution, which are formed by the copolymers and homopolymers investigated due to their chemical structure. The rad ii of gyration were calculated from the intrinsic viscosities with the aid of the Flory-Fox equation. However, neither the results obtained with the Flory-Fox constant PHI-0 = 3,69 . 10(24) mol-1, nor those wit h the value of PHI-0 = 2,10 . 10(24) mol-1 showed good agreement with the experimentally recorded data.