Synthesis, characterization and rheological properties of three different microstructures of water-soluble polymers prepared by solution polymerization

Three different structures were synthesized via solution free radical polymerization. Polyacrylamides hydrophobically modified with small amounts of two different N′N-dialkylacrylamides [N,N-dihexylacrylamide (DHAM) and N,N-dioctylacrylamide (DOAM)] and two different N-alkylacrylamides [N-dodecylacrylamide (DAM) and N-hexadecylacrylamide (HDAM)] have been synthesized using two linear hydrophobic initiators with 12 (ACVA₁₂) and 16 (ACVA₁₆) carbon atoms and two di-substituted hydrophobic initiator with two chains of 6 (ACVA_di6) and 8 (ACVA_di8) carbon atoms derived from 4′4-azobis(4-cyanopentanoic acid) (ACVA). The polymers obtained were telechelic, multisticker and combined. The initiators, monomers and polymers synthesized were characterized by ¹H NMR and light scattering (LS). The rheological properties of these three different associative polymers were investigated using steady-state experiments. The effect of location and structure (linear or di-substituted) of the hydrophobic groups upon the viscosity of the polymer in solution was studied.