Design and synthesis of biodegradable antiscalant based on MD simulation of antiscale mechanism: A case of itaconic acid-epoxysuccinate copolymer

Abstract

Antiscalants commonly used are difficult to be degraded and research of new antiscalants still relies on experiments. Therefore, molecular dynamics was applied to simulate interactions of five different molar ratios of poly(itaconic acid-co-epoxysuccinic acid) (PIA-co-ESA) copolymers with calcite surfaces in aqueous solution. On the basis, PIA-co-ESA which shows excellent antiscaling performance was screened out, synthesized and characterized, and the optimal synthesis condition was obtained by single factor experiments. The crystal morphology of calcite was observed by SEM. The results indicate that when monomer ratio (nIA: nESA) is 4:1, dosage of initiator is 11%, reaction temperature is 85°C and reaction time is 4h, PIA-co-ESA possesses the largest binding energy and exhibits excellent scale inhibition performance, in agreement with experiment result. Scale inhibition efficiency increases as increase of PIA-co-ESA concentration, reaching to 100% at a level of 18mg·L−1 agent, which was determined with the static scale test method. The analysis of radial distribution function verified that binding energy originates from ionic bond and hydrogen bond, PIA-co-ESA retards the growth rate of crystal surfaces and results in changes of crystal morphology, according well with SEM results. The results provide theoretical and experimental data for antiscale mechanism study and synthesis of antiscalant.