Study On Homopolymerization Of Maleic Acid In Aqueous System

In this paper, the studies on homopolymerization of maleic acid(anhydride) at home and abroad was reviewed in detail. It is found that polymaleic acid is produced in an organic solvent in the presence of an oil-soluble polymerization initiator at industrial scale. However this process has disadvantages as following:(l) including the steps of polymerizing maleic anhydride and hydrolyzing the resulting polymer to give polymaleic acid. It need long period time. (2) high production cost because it need a great deal of organic solvent and expensive oil-soluble initiator. (3) causing severely environmental pollution and having potential fire dangers. (4) the production has poor property and its usages are limited. To overcome these problems, the author provides a process for producing polymaleic acid in water as the only polymerizationmedium in the presence of iron( III ) ammonium sulfatedodecahydrate as the catalyst, by the aid of hydrogen peroxide as the polymerization initiator. The production can be used as scale inhibitor and its static ratio of scale inhibition can amount to 94.1%. Its weight-average molecular weight and number-average weight molecular weight can amount to 883 and 693. Its molecular weight distribution is lower 1.27.Influencing factors such as recipe of initiator and catalyst,working-out of the synthesis process are involved. GPC is used to determine the molecular weight of polymaleic acid. Thereby the influences of the amount of catalyst on the molecular weight of the production were investigated. The structure of the polymer was studied with FTIR and 13C NMR.