DIELS-ALDER POLYMER OF N-(2-ANTHRYL)MALEIMIDE

Although Diels-Alder polymers have been investigated extensively, relatively few have involved the anthracene moiety. A recent study of Diels-Alder polymerization of (9-anthryl)methyl methacrylate and (9-anthryl)methyl propiolate and an earlier one of the Diels-Alder copolymerization of 9,9 prime -linked bisanthracenes with bismaleimides led to very low-molecular-weight polymer. It has been suggested that substitution at the site of cycloaddition might be hindering formation of high-molecular-weight polymer in the case of 9-substituted anthracenes. This communication describes the Diels-Alder polymerization of N-(2-anthryl)maleimide which contains a reactive dienophile unit attached at a position remote from the site of cycloaddition, thus minimizing steric interference. The course of polymerization has been followed by UV and IR-spectroscopy. Data are presented which show that steric effects are not the only factor preventing formation of high-molecular-weight anthracene-based Diels-Alder polymers. Reversibility of the Diels-Alder reaction, which has been shown to be significant with Diels-Alder reactions of anthracene and dienophile at 1:1 mole ratios, might also be a contributing factor.