通过在聚氨酯泡沫塑料制备过程中加入不同用量的N-甲基二乙醇胺(简称N-MDA),并对聚氨酯泡沫进行酸化处理,得到了一系列阳离子型聚氨酯泡沫塑料(简称改性PUF),并对其结构和性能进行了研究.结果表明,以醋酸和磷酸(质量比为1∶1)作为N-MDA的催化抑制剂,可在较宽N-MDA用量范围内顺利合成改性PUF.随着N-MDA用量的增加,改性PUF的回弹率、拉伸强度及断裂伸长率均出现先增强后降低的趋势,而阳离子含量和亲水性不断增加.进一步将改性PUF作为固定化载体用于吸附活性污泥,结果显示,由于亲水性的增强和静电相互作用,改性PUF对活性污泥的吸附速度明显高于普通聚氨酯泡沫(简称对比PUF),其对活性污泥的单位体积吸附量最高可达180 g/L,是对比PUF(80 g/L)的2倍以上.
A series of hydrophilic cationic polyurethane foams (defined as modified PUFs) were prepared by using N-methyl diethanolamine (defined as N-MDA) as the reactant and treating the foams by hydrochloric acid. The catalytic activity of N-MDA was effectively inhibited by using the mixture of phosphoric acid and acetic acid as the acidic inhibitor and the PUFs were successfully prepared at high amount of N-MDA. The structures and properties of the resulting samples were analyzed by IR spectrometer, contact angle measuring instrument, electronic stripping tester, conductivity meter and zeta potential meter. With increasing the amount of N-MDA,the cation content and hydrophilicity of the samples increased gradually,but the elastic resilience, tensile strength and elongation at break increased first and then decreased. Furthermore,The modified sample was used as a novel microorganism immobilized carrier for adsorbing activated sludge. The resuhs indicated that the modified PUF displayed a higher adsorption rate for activated sludge than the unmodified one (defined as contrast PUF). And its highest adsorption capacity for activated sludge could reach 180 g/L,more than two times of the capacity (80 g/L) of the contrast PUF. The adsorbing processes of these two carriers were explained based on the hydrophilieity of their backbone surfaces and the electrostatic attraction between the carrier and activated sludge. The improved adsorption property should make the modified PUF suitable for application in microbial immobilization.