Properties of polyelectrolytes: poly(mono-methyl itaconate). conformational and viscometric behaviour in dilute solution

The dilute solution behaviour of poly(mono-methyl itaconate) (PMMI) has been studied in organic solvents, and in water at different degrees of neutralization (different pH), at 298 K, by intrinsic viscosity, osmometry measurements and size exclusion chromatography. Number-average molecular weight was determined in methanol; this solvent was found to be a theta solvent at 298 K. PMMI shows typical polyelectrolyte viscometric behaviour. The Kuhn-Mark-Houwink-Sakurada relationships were established in the various media studied. The conformational parameters (σ and C_γ) and the thermodynamic parameter (B) were calculated at various degrees of neutralization. The results are compared with those for other very simple polyelectrolytes such as poly(acrylic acid) and poly(methacrylic acid) (PMAA). Both PMMI and PMAA exist in a more expanded conformation in organic solvents than in aqueous solvents.