INFLUENCE OF THE STRUCTURE AND COMPOSITION ON SURFACE-TENSION OF AQUEOUS-SOLUTION OF GRAFT-COPOLYMERS OF POLYACRYLAMIDE BACKBONE AND POLYALKYLENEOXIDE BRANCHES

Polyacrylamide homopolymers and graft copolymers of poly(acrylamide-g- ethylene oxide) and poly(acrylamide-g-propylene oxide) were synthesize d, characterized by SEC, FTIR and C-13-NMR and the behavior of their a queous solutions was evaluated by surface tension measurements. By usi ng the macromonomer technique, it is more difficult to incorporate pol y(propylene oxide) branches than poly(ethylene oxide) branches. Graft copolymers of polyacrylamide and poly(propylene oxide) showed higher r eduction of surface tension than poly(acrylamide-g-ethylene oxide) sin ce they present a structure made up of hydrophilic and hydrophobic seg ments, Poly(acrylamide-g-propylene oxide) exhibits surfactant behavior , and the surface tension of its aqueous solution depends on the poly( propylene oxide) graft chain length and amount.