衣康酸-天冬氨酸共聚物合成及其阻垢性能的研究

Synthesis and scale inhibition performance of itaconic acid-asparagic acid copolymer

针对目前国内使用的阻垢剂存在难降解、易造成水体富营养化等问题,以衣康酸(IA)、天冬氨酸(ASP)为单体,过硫酸铵为引发剂,采用水溶液自由基聚合法合成了可生物降解的IA-ASP二元共聚物,并对产物结构进行红外表征。探讨单体配比、引发剂用量、聚合温度、反应时间对共聚物阻垢性能的影响,通过正交实验和单因素实验确定最佳合成条件。采用静态阻垢法考察阻垢剂用量、阻垢实验温度对阻碳酸钙垢性能的影响,并借助扫描电镜观察碳酸钙垢的晶体形貌,探讨其阻垢机理。结果表明:共聚单体的物质的量比(n_(IA)∶n_(ASP))为4∶1,引发剂用量为单体总质量的9%,反应温度85℃,反应时间2 h时,合成的IA-ASP共聚物对碳酸钙的阻垢率可达95%以上。IA-ASP共聚物作为阻垢剂适用于中低水温环境,其阻垢率随阻垢剂用量增加逐渐提高,最终趋于平缓。IA-ASP共聚物阻垢机理主要涉及螯合、分散作用及晶格畸变。

At present,scale inhibitors used in domestic are difficult to be degraded and easy to cause eutrophication. In view of the above problems,the biodegradable IA-ASP copolymer was prepared from itaconic acid（IA）and asparagic acid（ ASP）by free-radical polymerization in aqueous solution,with ammonium persulfate as initiator,and the structure of IA-ASP copolymer was characterized byinfrared spectrum. The effect of monomer ratio,the amount of initiator,reaction temperature and reaction time on the copolymer,s scale inhibition performance was discussed, and the optimum experimental condition was obtained by orthogonal and single factor experiments. The effect of amount of copolymer and temperature on scale inhibition efficiency was investigated using the static ex-periment method,and the crystal morphology of calcium carbonate was analyzed by scanning electron microscope. Furthmore, the mechanism of scale inhibition was discussed. The results showed that the scale inhibition efficiency of IA-ASP copolymer against calcium carbonate scale was above 95 % , when monomer ratio （ n IA ： nASP ） was 4 ： 1, the amount of initiator was 9 % of the totalmass of monomers,the reaction temperature was 85 Tiand the reaction time was 2 h. As scale inhibitor,IA-ASP copolymer was suitable for low and medium water temperature. Efficiency of scale inhibitor increased with the increase of IA-ASP copolymer amount,and e-ventually tends to be gentle. The mechanism of scale inhibition of IA-ASP mainly refered to chelation, dispersion and lattice deform-ation.