The association of aqueous phenolic resin with polyethylene oxide and poly(acrylamide‐co‐ethylene glycol)

Abstract Comb copolymers formed from acrylamide and poly(ethylene‐glycol) methacrylate macro‐monomer (PAM‐co‐PEG) were compared to poly(ethylene oxide) (PEO) with respect to hydrogen bond complex formation with water‐borne phenolic resins. The behaviors of the two types of high molecular weight polyethers were similar. Complex formation gave a transient increase in viscosity followed by precipitation. Copolymers with pendant PEG chain lengths ≥ 9 formed complexes with phenolic resin whereas PEG homopolymer with a molecular weight of 2000 did not form a complex. For both copolymer and high molecular weight PEO, the tendency of the complex to precipitate increased when the pH was decreased from 7 to 4. Acridine orange, a cationic dye, bound to the phenolic resin and, after the addition of PEO, yielded visible complex gels with diameters about 20 μm. © 1995 John Wiley & Sons, Inc.