硫酸钙防垢剂的合成与性能评价

摘要

A scale inhibitor, poly(maleic anhydride-acrylic acid-sodium allylsulfonate) terpolymer(BSI), was synthesized by the copolymerization of maleic anhydride, acrylic acid and sodium allylsulfonate with ammonium persulfate as the initiator. The effects of BSI concentration, temperature, time, pH, NaCl concentration and the concentrations of scale-forming ions(Ca2+and SO2-4) on the scale inhibition rate of BSI for calcium sulfate scale were studied. The effect of the BSI concentration on the scale inhibition rate with high Ca2+and SO2-4 concentrations was investigated. The results show that the scale inhibition rate would be 99.0% under the conditions of 70 ℃, 25 h, p(BSI) 3 mg/L, c(Ca2+) 0.1 mol/L, c(SO2-4) 0.1 mol/L, system pH 8 and p(NaCl) 7.5 g/L. The scale-forming ion concentration has a great influence on the scale inhibition rate. With increasing the BSI concentration, its scale inhibition effect for the solution with high scale-forming ion concentration is better and under the conditions of c(Ca2+) 0.6 mol/L, c(SO2-4) 0.6 mol/L and p(BSI) 220 mg/L the scale inhibition rate can reach 99.0%. According to the characteristics of the molecular structure of BSI, its inhibition mechanism was analyzed, in which BSI and Ca formed a complex. The dispersion flocculation and lattice distortion of BSI were discussed also.%以顺丁烯二酸酐、丙烯酸和烯丙基磺酸钠为原料,以过硫酸铵为引发剂,经共聚反应制得硫酸钙防垢剂聚顺丁烯二酸酐-丙烯酸-烯丙基磺酸钠三元共聚物(BSl)；考察了BSI含量、温度、时间、体系pH、NaCl含量、成垢离子(Ca2+和SO42-)浓度对防垢率的影响,同时考察了BSI含量对高浓度成垢离子溶液防垢率的影响.实验结果表明,在70℃、25 h、ρ(BSI) =3mg/L、c (Ca2+)=c(SO42-) =0.1 mol/L、体系pH=8、ρ(NaCl) =7.5 g/L的条件下,防垢率为99.0％.成垢离子浓度对BSI的防垢率影响很大,对于高浓度成垢离子溶液,增加BSI用量仍可使其具有较好的防垢效果；当溶液中c(Ca2+)=c(SO42-) =0.6 mol/L、ρ (BSI) =220 mg/L时,防垢率仍可达到99.0％.根据BSI的分子结构特点,分析了BSI与Ca2+形成络合物的络合机理,还进一步探讨了BSI的分散絮凝和晶格畸变作用机理.