MWCNTs增强聚乙二醇-聚乙烯醇复合水凝胶的制备及性能

摘要

Carboxy-functionalized multi-walled carbon nanotubes(MWCNTs)/polyethylene glycol (PEG)-poly-vinyl alcohol (PVA) composite hydrogels were prepared by the freezing/thawing method.The microstructure,swelling property,tensile strength,thermal stability and conductivity of MWCNTs/PEG-PVA composite hydrogels with different mass ratios were studied.The results show that the MWCNTs/PEG-PVA hydrogel still has a porous 3D structure,but the pore size becomes smaller after the addition of MWCNTs.When the mass ratio of MWCNTs to PVA is larger than 1.0:100,the uniformity of the porous structure of the MWCNTs/PEG-PVA hydrogel decreases.With the increment of MWCNTs content,the swelling degree and tensile strength of the MWCNTs/PEG-PVA composite hydrogel increase first and then decrease.When the mass ratio of MWCNTs to PVA is 1.0:100,the swelling degree and porosity of the MWCNTs/PEG-PVA hydrogel reach the maximum (1450% and 75.8%,respectively).The tensile strength and elongation reach a maximum value of 0.97 MPa and 384.0%,respectively.The addition of MWCNTs improves the thermal stability of the composite hydrogel,and the initial thermal decomposition temperature of MWCNTs/PEG-PVA composite hydrogel increases from 235℃ to 260℃.With the increment of the amount of MWCNTs,the conductivity of the composite hydrogel increases from 1.10×10-6 S/cm to 6.96×10-4 S/cm.%利用冻融循环法制备了羧基化多壁碳纳米管(MWCNTs)/聚乙二醇(PEG)-聚乙烯醇(PVA)复合水凝胶.考察了不同质量配比下MWCNTs/PEG-PVA复合水凝胶的微观形貌变化,并研究了复合凝胶的溶胀性能、拉伸强度、热稳定及导电性能.结果表明,加入MWCNTs后MWCNTs/PEG-PVA复合凝胶仍具有多孔的三维网状结构但孔径尺寸变小.当MWCNTs与PVA的质量比大于1.0:100时,MWCNTs/PEG-PVA复合凝胶的孔洞均匀性降低.随着MWCNTs量的增加,MWCNTs/PEG-PVA复合凝胶的溶胀度及拉伸强度均先升高后降低.当MWCNTs与PVA的质量比为1.0:100时,MWCNTs/PEG-PVA复合凝胶的溶胀度达到最大(1450%),孔隙率最高(75.8%),拉伸强度及断裂伸长率达到最大值,分别为0.97 MPa和384.0%.MWCNTs的加入提高了MWCNTs/PEG-PVA复合凝胶的热稳定性,MWCNTs/PEG-PVA复合凝胶的初始热分解温度从235℃上升至260℃;随着MWCNTs量的增加,MWCNTs/PEG-PVA复合凝胶的电导率从1.10×10-6 S/cm升高至6.96×10-4 S/cm.