聚天冬氨酸的微波合成及其天然海水阻垢性能

Microwave-assisted synthesis of polyaspartic acid and effect on scale resistance in seawater

以水为溶剂,以马来酸酐和NH·HO为起始原料,不添加有机溶剂和催化剂,微波辅助下一锅法串联亲核加成反应和聚合反应生成缩聚琥珀酰亚胺(PSI),进一步对PSI水解生成聚天冬氨酸(PASP)。通过红外光谱和核磁共振对聚合及水解产物进行了结构表征。通过正交实验和单因素实验,详细考察了反应物比例、微波功率及反应时间等因素对PSI的产率和PASP分子量的影响,并以天津汉沽地区的天然海水为例,探究其海水阻垢性能,构建了反应条件-分子量-阻垢性能之间的对应关系。结果表明,微波辅助加热可以大大加速亲核加成和聚合反应进程,聚合物的阻垢率与分子量呈正相关。在马来酸酐/NH_(3)·H_(2)O配比为1.2、微波功率为600W、反应时间为10min的优化实验条件下,PSI收率可达91%以上,PASP数均分子量达Mn 4610,对汉沽天然海水阻垢率达到95%。

Polyaspartic acid(PASP)is a well-recognized green water treatment agent, with excellent biodegradability and good anti-scaling ability, which has been attracting ever-increasing interest in the field of seawater anti-scaling both domestically and internationally. Using water as the reaction medium, and under the assistance of microwave radiation, the polycondensation between maleic anhydride and ammonia results in polysuccinate(PSI)as the intermediate product, which can be further hydrolyzed in a base condition to give PASP. The anti-scaling performance was studied using the Tianjin Hangu seawater. The effect of the reactant ratio, the microwave power strength, as well as the radiation time, were investigated in detail in terms of the yield of PSI, and the molecular weight and anti-scaling efficiency of PASP. The relationship between reaction conditions, molecular weight and scale inhibition performance was constructed. The optimized conditions were given: maleic anhydride/ammonia ratio of 1.2, microwave power of 600W and reaction time of 10min. Under the optimized conditions, a high yield of over91%, and high scale inhibition rate of over 95% was achieved.