酚羟基修饰超高交联吸附树脂的制备与性能

以明胶为分散剂,液体石蜡为致孔剂,交联反应中用溴乙烷代替有毒的氯甲醚,分别以苯酚和萘酚参与Friedel-Crafts后交联反应,成功制备了酚羟基修饰的超高交联聚苯乙烯吸附树脂LM-5和LM-6.树脂物理性能研究表明:LM-6具有更大的比表面积和酚羟基含量,且在苯胺和苯的混合溶液中对苯胺的选择系数高于LM-5;扫描电镜(SEM)分析表明,两种超高交联吸附树脂符合纳米吸附高分子材料特征.选择性吸附及吸附平衡研究表明:树脂LM-6在水体系中对苯胺和苯的吸附均以物理吸附为主,对苯胺的吸附过程伴随有化学吸附,对苯胺的吸附焓在氢键吸附焓范围内;由于氢键的形成,LM-6对苯胺的吸附量明显高于对苯的吸附量;pH值在1.0~5.0时,LM-6对苯胺的吸附量略有增加,而对苯的吸附量显著下降,对苯胺的选择系数迅速增加.

Preparation and adsorption performance of hypercrosslinked polymeric adsorbents modified by phenolic hydroxyl group

By Friedel-Crafts post-crosslinking reaction with phenol and naphthol,the hypercrosslinked polystyrene adsorbents of LM-5 and LM-6 were prepared using gelatin as dispersant and liquid paraffin as porogen.Bromoethane was used as crosslinking reagent to substitute poisonous organic compound of chloromethyl methylether.The physical properties of absorbents illuminate that both phenolic hydroxyl group content and BET surface area of LM-6 are higher than those of LM-5.The scanning electron microscope(SEM) spectrogram showed that the hypercrosslinked polymeric adsorbents modified by phenolic hydroxyl group can be viewed as nanometer polymeric resins.The experiments of selective adsorption and equilibrium adsorption show that the adsorbing aniline and benzene on LM-6 in aqueous solution are pushed mainly by physical force.Adsorbing aniline also partly depends on chemical force,and the value of adsorptive enthalpy illuminates the characteristic of hydrogen-bonded sorption.Owing to the forming of hydrogen-bond,the adsorption capacity of aniline on LM-6 is distinctly higher than that of benzene.Selectivity of LM-6 adsorbing aniline is slightly enhanced by the increasing of pH value,while the adsorptive capacity of benzene on LM-6 markedly decreases,and the selectivity of aniline distinctly increases.