Excluded volume and surface activity of block copolymers with lonizable groups: Lonene-tetrahydrofuran block copolymers

Abstract

Abstract ABA type block polyelectrolytes were prepared by quarternization reaction of the one end of 3, 3-ionene chloride (A) with end-brominated polytetrahydrofuran (B). Intrinsic viscosities of the block copolymers were measured in KBr-methanol solution and the viscosity equations were established. The excluded volume effect of the block polyelectrolyte was examined by using the theories of Kurata, Alexandrowicz, Ptitsyn, and Fixman. The expansion factor α3 was a function of ī(N/CS)½, even for the block polyelectrolyte, where ī is the degree of ionization, N is the degree of polymerization, and Cs is the salt concentration, and Ptitsyn's excluded volume function for block polyelectrolyte did not fit the experiments. Since the block polyelectrolyte was surface-active, the surface tension of the aqueous block co-polymer solutions was also measured. The direct measurements of the surface excess and the thickness of adsorbed block co-polymer layer were carried out by ellipsometry. The observed values of sur...