Polymers and group interaction. VIII. Synthesis of a styrene–amino acid copolymer

Abstract

Abstract A copolymer of styrene–maleimide has been obtained by reaction of a styrene–maleic anhydride copolymer with ammonia under pressure in acetone solution at 70–90°C. The co(styrene–maleimide) polymer was submitted to Hofmann degradation reaction in aqueous medium and in water– tert ‐butyl alcohol solution. In aqueous solution the amine formation is accompanied by partial lactam formation resulting from interaction between acid and amine groups. In water– tert ‐butanol this cyclization reaction did not take place, since there was formation of tert ‐butyl carbamates. These carbamate groups may be hydrolyzed in acetic acid solution in the presence of hydrochloric acid, and afford free amino groups. In both media, appreciable hydrolysis proceeds simultaneously with the Hofmann reaction, so that the number of carboxyl groups exceeds by far the number of amino groups (75 vs. 20–25%).