纤维素纳米纤维的疏水改性及其在纸张中的应用

Hydrophobic Modification of Cellulose Nanofibrils and Their Application in Paper

本研究基于水相一锅两步法对纤维素纳米纤丝(CNFs)进行疏水改性,重点研究了没食子酸(GA)、没食子酸甲酯(MG)、没食子酸乙酯(EG)、没食子酸丙酯(PG)及原儿茶酸(PCA)5种植物多酚对CNFs疏水改性的影响,并对疏水改性CNFs在纸张涂布中的应用进行了探究。结果表明,植物多酚(GA、MG、EG、PG及PCA)均能协同十八胺(ODA)对CNFs进行疏水改性;且CNFs的疏水改性作用效果随植物多酚结构中碳链的延长而增强。疏水改性CNFs能够赋予纸张较好疏水性,PCA改性CNFs涂布纸的疏水性强于GA改性CNFs涂布纸的疏水性;PG改性CNFs涂布纸的水接触角较ODA涂布纸的水接触角提高了43%,且疏水改性CNFs涂布纸在干、湿状态下均能保持较好的抗张强度。

In this study,the hydrophobic modification of cellulose manofibrils(CNFs)was achieved based on an effective one-pot two-step meth‐od.The effects of five different plant polyphenols including gallic acid(GA),methyl gallate(MG),ethyl gallate(EG),propyl gallate(PG),and protocatechuic acid(PCA)on the hydrophobic properties of CNFs were emphatically investigated.Subsequently,the application of modified CNFs in paper coating was discussed.The results showed that the chosen plant polyphenols(GA,MG,EG,PG and PCA)could work together with octadecamine(ODA)to achieve the hydrophobic modification of CNFs.Moreover,the hydrophobic modification effect of CNFs was en‐hanced with the growth of carbon chains in the plant polyphenol’s structure.The hydrophobic modified CNFs could impart paper with improved hy‐drophobicity.The hydrophobicity of CNFs coated paper modified through PCA was better than that of CNFs coated paper modified through GA.Af‐ter coating through PG modified CNFs,the water contact angle of the CNFs coated paper was 43%higher than that of the ODA coated paper.More‐over,the hydrophobic modified CNFs coated paper could maintain desired tensile strength under dry and wet conditions.