Tóm tắt
AbstractThe trans isomers of both poly(4′‐vinylbenzalacetophenone) and a model compound, 4′‐ethylbenzalacetophenone, readily form the corresponding cis isomers on exposure of their solutions to ultraviolet radiation. The cis isomers can be isolated and, in the case of the nonpolymeric material, the cis form reverts readily to the trans form upon addition of a trace of hydrogen chloride. The polymer, however, only partially reverts to the trans form. An explanation is offered to account for this, namely, that, even in dilute solution, intramolecular dimerization occurs in the coiled polymer. These tie points in the polymer chain prevent complete reversion to the trans form.
