Formation of crystalline polyelectrolytic complexes on matrix polymerization

Zwitterionic matrix stepwise polymerization of 4-vinylpyridine (VP) using isotactic poly(acrylic acid) (i-PAA) as a template results in formation of crystalline polycomplexes consisting of i-PAA and of ionene (I): Depending on the concentration of VP and i-PAA, the two types of crystalline polycomplexes can be prepared. The complex containing long ionene sequences with n ≫ 2 is formed when [VP]0 = [i-PAA]0 ≥ 0.05M. At [VP]0 = [i-PAA]0 ⩽ 0.01M, the complex formed evidently contains the ionene dimer (n = 2). The x-ray structures of the crystalline complexes are identical with those obtained by mixing of i-PAA and the corresponding dimer and polymer presynthesized in the absence of the template. The matrix polymerization of VP in the presence of syndiotactic and atactic PAA at the same conditions results in formation of amorphous polycomplexes.