纤维素骨架支撑的高吸水性树脂的制备及性能研究

Preparation and Properties of Cellulose-supported Superabsorbent Resin

关键词:  竹浆纤维  预处理  高吸水性树脂  吸水倍率  溶胀行为

Key Words:bamboo pulp cellulose  pretreatment  superabsorbent resin  water absorption rate  swelling behaviors

摘要:本研究以竹浆为原料，通过复合纤维素酶+低温碱尿素体系预处理得到改性竹浆纤维；然后以过硫酸钾为自由基引发剂，在N,N’-亚甲基双丙烯酰胺的作用下，将丙烯酸接枝到改性竹浆纤维上，制备了一种新型纤维素骨架支撑的高吸水性树脂（MBPF-g-PAA）。采用傅里叶变换红外光谱仪、热重分析仪、X射线衍射仪、X射线光电子能谱仪和场发射扫描电子显微镜对MBPF-g-PAA的结构和形貌进行表征。结果表明，聚丙烯酸成功接枝到竹浆纤维上，纤维素作为骨架增强了树脂内部多孔结构，树脂的吸水效果有明显改进；在优化合成条件下，MBPF-g-PAA的吸水倍率最高达980.87 g/g。此外，受金属阳离子“电荷屏蔽效应”的影响，不同阳离子盐溶液对树脂溶胀的影响依次为：Na⁺ > K⁺ > NH₄⁺ > Mg²⁺ > Ca²⁺ > Fe³⁺。

Abstract:In this study， the modified bamboo pulp fiber was prepared by pretreatment of complex cellulase and low temperature alkali urea system using bamboo pulp as the raw material. The potassium persulfate was as a free radical initiator， a new cellulose-supported superabsorbent resin （MBPF-g-PAA） was prepared with N，N’-methylenebisacrylamide as monomers. The structure and morphology of the resin were characterized by FT-IR， TGA， XRD， XPS， and FESEM. The results showed that polyacrylic acid was successfully grafted onto the cellulose fibers. The water absorption rate of the resin was improved obviously due to cellulose skeleton enhanced inner porous structure. Under the optimum pretreat conditions， the water absorption rate of the MBPF-g-PAA was 980.87 g/g. In addition， the swelling behaviors of the MBPF-g-PAA depended on the pH and the metal cation types of the salt solutions. Influencing by the “charge shielding effect” of metal cations， the effects of different cationic salt solutions on resin swelling rate were as follows： Na⁺ > K⁺ > NH₄⁺ > Mg²⁺ > Ca²⁺ > Fe³⁺.