The interpolymer specific interactions between acrylate copolymers with proton donor and proton acceptor in solutions were investigated by means of viscometry and light scattering．Poly(styrene/acrylate/acrylic acid) as proton donating polymer(PDP) and poly(styrene／acrylate／4-vinylpyridine) as proton accepting polymer(PAP) with various macromolecular chain compositions were prepared by emulsion copolymerization and the complexed solutions formed by PDP and PAP were prepared. A novel interpolymer interaction parameter ka based on the relationship of viscositv enhancement factor with theoretical specific viscosity of the blend

ηsp

m

cal

has been developed to study the interpolymer specific interactions in toluene．The effects of the content and alkyl length of acrylate on interpolymer interaction were discussed．The results show that with the change in mole fraction of AA (FAA) in blends

there existed a maximal ka indicating the strongest interaction between PDP and PAP．The mole fraction of AA corresponding to maximal ka

FAA

max

increases gradually up to 0.5 as OA content decreases in PDP and relatively insensitive to composition of PAP. The interpolymer interaction between PDP and PAP is increased with increasing OA content in component copolymers due to Van der Waals force between side chains of OA unit on unlike macromolecular chalns．The enhancement of the interpolymer specific interaction can also be realized by increasing the alkyl length of acrylate．Light scattering experiments confirm that ka can act qualitatively as measure of the magnitude of the interpolymer interaction ability.