Chemical Modification as a Method for Investigation of the Microstructure of Copoly(arylene phthalide)s

Previously, it has been shown that poly(diphenylene sulfide phthalide) can be oxidized quantitatively to polysulfone by hydrogen peroxide in acetic acid. Using this method to oxidize the sulfide groups in copoly(arylene phthalide)s containing diphenylene sulfide and diphenylene oxide fragments, we obtained copolymers with electron-donating (‐O‐) and electronaccepting ( − SO 2 – ) groups in alternating sections of the polymer chain. Presumably, in the ionized chains of these modified copoly(arylene phthalide)s, the charge would be concentrated within the conjugation blocks of the electrondonating units, separated by the sulfonic groups. An even more complicated pattern of electron density distribution along the ionized (excited) macromolecule should be expected in incompletely oxidized poly(diphenylene oxide‐diphenylene sulfide phthalide)s. By varying the composition and the microstructure of the initial copoly(arylene phthalide)s (random, alternating, or block) and the degree of conversion of sulfide groups, one can obtain a broad range of polymeric products differing in both the pattern of alternation and the length of the electron-donating and electron-accepting sequences. The process of modification also deserves attention because the dependence of the oxidation rate of the sulfide group on the structure of chain sections adjacent to the diphenylene sulfide fragment bears additional information on the microstructure of the initial copoly(arylene phthalide)s.