The effect of polyethyleneglycol methacrylate and vinylsulfonic acid copolymer on the calcium oxalate crystallization

THE EFFECT OF POLYETHYLENEGLYCOL METHACRYLATE ANDVINYLSULFONIC ACID COPOLYMER ON THE CALCIUM OXALATECRYSTALLIZATIONSEMRA KIRBOĞAThe control of crystal growth and morphology of crystal is considerable importance inindustrial crystallization and medical area. The formation of scales that is caused bycalcium salt which has low solubility in heat exchanger or cooling tower process is leadto serious problems such as pollution, decreasing of heat transfer. Among the manyfactors affecting the process of crystallization e.g temperature, supersaturation,agitation, especially admixtures have strong effect on the crystallization.In this study, the effects of additives on crystallization of calcium oxalate monohydrate(CaC2O4.H2O, COM) have been investigated in aqueous solutions. Vinyl sulfonic acidhomopolymer and polyethyleneglycol methacrylate-co-vinyl sulfonic acid copolymers(PEGM-co-VS), having different number of sulfonic acid group, have been used asadditives. The effect of polymers on the rate of precipitation of COM was determinedby recording the decrease of solution conductivity as a function of time. The structure ofpolymer and the number of vinyl sulfonic acid group at the copolymers were found tobe important parameters in inhibition of calcium oxalate monohydrate crystallization.Keywords: Calcium oxalate crystallization, polymers and inhibitors.