2种羧基化纤维素衍生物对聚丙烯酰胺复合水凝胶力学性能的影响  

Influence of Two Carboxylated Cellulose Derivatives on Mechanical Properties of Polyacrylamide Composite Hydrogels

作　　者：马颖 王建全 李向梅 邵自强 Ying Ma;Jianquan Wang;Xiangmei Li;Ziqiang Shao(Beijing Engineering Research Center of Cellulose and Its Derivatives,School of Materials Science&Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学材料学院北京市纤维素及其衍生材料工程技术研究中心,北京100081

出　　处：《高分子材料科学与工程》2021年第10期137-144,共8页Polymer Materials Science & Engineering

基　　金：中央高校基本科研业务费专项资金(2021CX02043)。

摘　　要：为了深入理解羧基化纤维素衍生物聚集态结构和羧基含量对金属络合型复合水凝胶的增强增韧作用,文中分别在2种羧基化纤维素衍生物——聚阴离子纤维素(PAC)和TEMPO氧化纤维素纳米纤维(CNF)水体系中,进行了丙烯酰胺(AM)的自由基水溶液聚合,制备了PAM基复合水凝胶,进而经0.1 mol/L ZrOCl_(2)水溶液处理,获得了力学性能更为优越的Zr(IV)络合型复合水凝胶。通过红外光谱、扫描电镜和压缩/拉伸力学对所得水凝胶进行了表征。结果表明,CNF或PAC的引入增强了PAM的氢键作用,赋予了水凝胶较高的力学性能,同等加量下纳米纤维状的CNF对PAM基水凝胶的增强效果高于PAC;引入Zr(IV)络合作用后,复合凝胶显著溶胀,但其内部网络结构却变得更加致密,PAC凝胶体系还出现了相互交织的纳米纤维结构;强烈的Zr(IV)-COO^(-)络合作用使凝胶的力学性能大幅提高,同等加量下羧基含量较多的PAC增强效果更佳;羧基含量接近时,纳米结构的CNF增强效果更优。The present study was performed aiming to understand the reinforcing and toughening effects of carboxylated cellulose derivatives with different aggregation structures and carboxylate contents on metal-coordinated composite hydrogels. Zr(IV)-coordinated polyacrylamide(PAM) composite hydrogels with high mechanical performance were fabricated via free radical polymerization of acrylamide(AM) in aqueous systems of TEMPO-oxidized cellulose nanofibers(CNF) or polyanionic cellulose(PAC), followed by posttreatment in 0.1 mol/L zirconyl chloride aqueous solution. The obtained hydrogels were characterized by FT-IR, SEM and compressive/tensile mechanics. The incorporation of CNF or PAC improves the hydrogen bonding interaction in PAM networks, strengthens the mechanics of composite hydrogels, and nanostructured CNF exerts higher effect than PAC at the same dosage. After treated with 0.1 mol/L ZrOCl_(2), the composite hydrogels behave obvious swelling, but their network structures become denser, and intertwined nanofibrils are found within PAC composited hydrogel networks. For mechanical properties, Zr(IV)-coordinated hydrogels demonstrate significant enhancement effect benefiting from strong Zr(IV)-COO^(-)interactions. At the same amount, PAC plays a much higher role than CNF due to its higher carboxylate content, while the enhancement from CNF is slightly better than that from PAC at the similar carboxylate content. This research provides some implications for designing multivalent metal-coordinated hydrogels composited with carboxylated cellulose derivatives.

关 键 词：水凝胶 聚丙烯酰胺 纤维素纳米纤维 聚阴离子纤维素 金属络合作用 

分 类 号：TQ427.26[化学工程]