Radiation-induced cross-linking of polyvinylpyrrolidone-poly(acrylic acid) complexes

Interpolymer complexes were obtained using high-molecular-weight polyvinylpyrrolidone and oligomeric poly(acrylic acid) as substrates. Turbidimetric and viscometric studies indicate that complexation is most pronounced at a molar PAA fraction of ca. 0.8, and that the critical pH values for complex formation are in the range 3.7-4.0, depending on the molar ratios of components. Irradiation of PAA-PVP complex structures by pulses of fast electrons in dilute, deoxygenated solutions induces intramolecular (intra-complex) cross-linking, evidenced by decrease in viscosity and radius of gyration, leading to the formation of permanent PAA-PVP nanogels.