Studies on the complex formation of syndiotactic poly(methacrylic acid) with complementary polymers through the hydrogen bonding

Abstract

Complex formations between syndiotactic poly(methacrylic acid) (st-PMAA) and poly(N-vinyl pyrrolidone) (PVP), and that between st-PMAA and polyethyleneoxide (PEO) through hydrogen bonding were studied by viscosity and potentiometry. Reduced viscosity ($\eta$red) was measured at various mole fraction of PVP or PEO with respect to a constant amount of st-PMAA. Observation shows a sharp minimum at the 1:1 mole ratio of st-PMAA : PVP or st-PMAA : PEO, which shows that the complexation becomes optimal and the complex has a compact structure in this case. Variation of pH also supports this conclusion. This is the case of the system of st-PMAA and PVP in water as well as in DMF. Also the complexation is much enhanced when the molecular weight of PVP is high. Meanwhile, the system of st-PMAA and PEO shows a little different behavior, i.e., this system does not form the complex in DMF and dose only in water. It is because the interaction st-PMAA with PEO is weaker than that with PVP.