磺酸基团对高吸水性聚合物耐盐性的影响

针对高吸水性聚合物(SAP)耐盐性较差的问题,采用水溶液聚合法以丙烯酸(AA)、丙烯酰胺(AM)和2-丙烯酰胺-2-甲基丙磺酸(AMPS)为单体合成三元共聚的SAP,研究磺酸基团对聚合物耐盐性的影响.单体配比研究表明,引入AMPS前后,SAP在蒸馏水中30 min的吸液率分别为615 g/mL和695 g/mL; 在0.9%NaCl溶液中吸液率分别为50 g/mL和75 g/mL.研究出合成SAP的较佳条件AMPS∶AM∶AA的摩尔比为0.5∶4∶3; 反应温度为60 ℃; 引发剂的用量为0.125%; 交联剂的用量为0.02%.合成的SAP在蒸馏水中和0.9%NaCl溶液中达饱和时的吸液率分别为1 350 g/mL和125 g/mL.表明AMPS的引入有效地改善了高吸水性聚合物的耐盐性.

Effect of sulfonate group on salt resistance of superabsorbent polymer

In order to solve the problem that the salt-resistance of superabsorbent polymer(SAP)is poor, the terpolymer SAP was synthesized through taking acrylic acid(AA), acrylamide(AM)and 2-acrylamido-2-methylpropane sulfonic acid(AMPS)as monomers with aqueous solution copolymerization method. The effect of sulfonate group on the salt-resistance of SAP was studied. The investigation on monomer ratio shows that before and after introducing AMPS, the absorption capacity of SAP in distilled water within 30 min is 615 g/mL and 695 g/mL, respectively. The absorption capacity of SAP in 0.9%NaCl solution is 50 g/mL and 75 g/mL, respectively. The better synthesis condition for SAP is that the mole ratio of monomers is 0.5(AMPS)∶4(AM)∶3(AA), the reaction temperature is 60 ℃ and the dosages of both initiator and crosslinking agent are 0.125% and 0.02%, respectively. The absorption capacity of synthesized SAP in both distilled water and 0.9% NaCl solution is 1 350 g/mL and 125 g/mL, respectively. The above-mentioned facts indicate that the introduction of AMPS can efficiently improve the salt-resistance of SAP.