Synthesis and evaluation of phosphate-free antiscalants to control CaSO4.2H(2)O scale formation in reverse osmosis desalination plants

摘要

Polysuccinimide (PSI) of various molecular weights (MW) was synthesized from aspartic acid. The PSIs were hydrolyzed with NaOH to obtain sodium polyaspartates. Partial hydrolysis of a PSI gave the copolymer poly(SI-co-sodium aspartate). PSIs were treated with one equivalent of cyclic amines: pyrrolidine, piperidine, and azepane to afford the corresponding polyaspartamides in excellent yields. Treatment of PSI with 0.5 equivalents of the cyclic amines led to the formation of 1:1 copolymer poly(SI-co-aspartamide) which on basic hydrolysis gave the corresponding 1:1 copolymer poly(sodium aspartate-co-aspartamide).