复合分散剂在反相悬浮制备吸水树脂中的应用

针对反相悬浮法制备丙烯酸系高吸水树脂存在反应体系稳定性差,产品吸水倍率不高,粒径大小不均匀等问题,提出采用复合分散剂体系合成高吸水树脂,调控体系的稳定性.考察了分散剂种类,单体中和度和搅拌速度对反相悬浮反应体系稳定性以及树脂性能的影响.实验结果表明：采用Span60/80复合分散剂,当分散剂质量比为1∶1,丙烯酸中和度为70％,搅拌速度为350 r/min时,树脂的吸水倍率最高可达960g/g,吸盐水倍率为115 g/g,比同类方法制得的树脂吸液倍率高1O％.体系的稳定性好,树脂颗粒均匀,平均粒径为0.34 mm.采用反相悬浮法制备的高吸水树脂具有一定的防潮能力,放在湿度为70％的环境中15h后,树脂吸湿量小,颗粒流动性良好.将反应体系由500 mL放大到1 000 mL、3 000 mL,反应体系的稳定性均很好,所得树脂粒径变化不大,为反相悬浮聚合制备高吸水倍率树脂的工业化生产提供指导.

Application of compound dispersant in preparation of superabsorbent by inverse suspension polymerization

To solve the problems of preparation of acrylic acid series superabsorbent polymer＇ s instable reaction system,low absorption rate and non-uniform particle size by the reversed-phase suspension technique,composite dispersant system was added into preparation for superabsorbent polymer.The effects of kinds and monomer neutralization degree of dispersants and stirring speed on the stability of inverse suspension reaction system and quality of the superabsorbent polymer were analyzed.The results of the experiment show that when compound dispersant span 60/80 with quality ratio of 1 ∶ 1 is used,neutralization degree of acrylic acid is 70％ and the stirring speed is 350 r/min,water-absorbency and saline solution absorption are up to 960 g/g and 115 g/g,respectively,which are 10％ higher than other products by similar methods; the stability of system is good; the particle size of the superabsorbent polymer is uniformed with average particle size of 0.34 mm.The superabsorbent polymer produced by inverse suspension has the ability of moisture proof; the moisture absorption ratio of which is small and the particles mobility is good under the environment of 70％ humidity after 15 h.When the reaction system is amplified from 500 mL to 1 000 mL and 3 000 mL,respectively,both of the reaction systems are stable,and the particle size of superabsorbent polymers changes obviously,which provides a reference for the preparation of superabsorbent polymer by inverse suspension in the industrial production.