Untersuchungen zur kettenspaltung und entstehung von π‐bindungen in der vinylkette von polystyrol in lösung unter sauerstoff‐ und lichteinfluß

Abstract

AbstractThe influence of the solvent on chain degradation of polystyrene (PS) as well as the formation of π‐bonds in the vinyl chain is investigated, the latter caused by irradiation of PS‐solutions with long wave UV light (λ ≥ 270 nm) and reactions of singlet‐oxygen O2 (1Δg). Unambiguous qualitative proof could be given for chain degradation of polystyrene under the given experimental reaction conditions. Quantitative considerations though, based on different oxygen content in the respective solutions, different tension of the macromolecular chain and/or different contraction of the macromolecular coils proved to be not tenable or incomplete. It is shown that under the given experimental conditions formation of π‐bonds in PS results from a reaction of chlorine radicals with PS molecules. The kinetics of π‐bond formation in CCl4 and CHCl3 solutions is investigated by light scattering measurements. The conclusions aim at a quantitative determination of the saturation state in the formation of π‐bonds in both solutions.