Copolymers of polyaspartic acid

摘要

Higher molecular weight copolymers of polyaspartic acid which are suitable for the inhibition of scale deposition may be obtained by reacting maleic acid and ammonia in a stoichiometric excess, with a diamine or a triamine, at 120 DEG -350 DEG C., preferably 180 DEG -300 DEG C., and then converting the copolymer of polysuccinimide formed to a salt of a copolymer of polyaspartic acid by hydrolysis with a hydroxide. Alkyl or substituted alkyl groups may be incorporated in the backbone of the polymer by adding a alkyl or substituted alkyl monoamine to maleic acid and ammonia and heating at 120 DEG C. or more until polymerization has occurred.