Study On The Synthesis And The Performance Of Epoxysuccinic Acid-2, 3-epoxypropylsulfonic Acid Copolymer

At present, in domestic and international markets, the staple scale inhibitors for water treatment are phosphorous compounds that have already given rise to the pollution of the environment. Their production and usage must be strictly controlled according to the environmental protection laws. The research and development of non-phosphorous and environmentally friendly water treatment agents must be one important trend in twenty-first century. Polyepoxysuccinic acid is a novel green water treatment agent developed abroad in recent years. It is reported that it has become the new hot point of water treatment agent industry for its excellent scale inhibition, dispersion, corrosion inhibition and biodegradability. Its research work just began in China. In this paper, sodium hydrogen epoxysuccinate has been produced by eopoxidizing maleate with hydrogen peroxide in the presence of an epoxidation catalyst-sodium tungstate. The structure of the product has been characterized by IR, 1HNMR and element analysis. The productivity of sodium hydrogen epoxysuccinate was 93.4% in the aqueous solution containing 75% by volume of alcohol. Polyepoxysuccinic acid has also been synthesized by polymerization of epoxysuccinate disodium salt in the presence of the initiator-calcium hydroxide. The polymer's structure has been also characterized by IR and 1HNMR. According to the test results, the optimal polymerization condition was that the molar ratio of the monomer to the initiator was 10:1 to 10:2, the reaction time about 2 hour and the reaction temperature 95℃. Three kinds of polyepoxysuccinic acid were synthesized under different reaction conditions, and the performance of scale inhibition was evaluated by static test. The zinc salt stabilization and the ferric oxide dispersion of the polymer were also evaluated in this paper. The following conclusions can be deduced from the results of the tests. (1) Polyepoxysuccinic acid (PESA) is a good inhibitor on calcium carbonate scale. Its scale inhibition efficiency improved if itsconcentration in aqueous system increased. But when its concentration was more than 15 mg .L-1, its calcium carbonate scale inhibition efficiency did not improved evidently. The calcium carbonate scale inhibition efficiency of PESA1 was 79.6% when its concentration in aqueous system was 7 mg .L-1. (2) Polyepoxysuccinic acid has good capacity of calcium sulfate scale inhibition. The calcium sulfate scale inhibition efficiency of PESA was more than 85% when its concentration in aqueous system was 2 mg .L-1, and the scale inhibition efficiency was more than 90% when the concentration was 5 mg .L-1. (3) Polyepoxysuccinic acid has poor capacity of calcium phosphate inhibition, zinc salt stabilization and ferric oxide dispersion. (4) The different polyepoxysuccinic acids synthesized under different conditions have different capacities in scale inhibition.It is reported that polymeric scale inhibitor's capabilities in calcium phosphate scale inhibition, zinc salt scale inhibition and metal ionic dispersion would improved if sulphoacid groups were introduced into the polymer's molecular. In this paper, the sodium 3-chloro-2-hydroxypropylsulfonate has been synthesized by epichlorohydrin react on sodium hydrogen sulfite at first, then sodium 2,3-epoxypropylsulfonate has been produced by sodium 3-chloro-2-hydroxypropylsulfonate react on sodium hydroxide, at last, epoxysuccinate-2,3-epoxypropylsulfonate copolymer (PECS) has been synthesized by copolymerization in the presence of the initiator--calcium hydroxide. The copolymer's structure was confirmed by IR and 1HNMR. A series of PECS was synthesized under different reaction conditions, and their performance of scale inhibition was evaluated by static test. The zinc salt stabilization and the ferric oxide dispersion of PECS were also evaluated in this paper. The following conclusions can be deduced from the results of the tests. (1) The copolymer's capacity in calcium carboate scale inhibition decreased compared with polyepoxysuccinic acid. The calcium...