Highly efficient and straightforward functionalization of cellulose films with thiol-ene click chemistry
作者:Philippe Tingaut、Roland Hauert、Tanja Zimmermann
DOI:10.1039/c1jm11620g
日期:——
Three efficient and straightforward chemical pathways have been studied to functionalize solid cellulose substrates, involving for the first time alkoxysilane chemistry coupled with the photochemical version of the thiol-ene reaction. The success of the reactions was confirmed using FTIR-ATR spectroscopy and XPS analysis, but different grafting efficiencies were observed depending on the combination used. In a first route, ene-functionalized cellulose films were synthesized using vinyltrimethoxysilane as coupling agent, and were photochemically coupled with methylthioglycolate (MeGlySH). A very fast reaction rate was observed for this reaction during the first 5 min. In a second route, the opposite reaction was envisaged by clicking allylbutyrate on a thiol-functionalized cellulose surface, previously synthesized using 3-mercaptopryltrimethoxysilane as coupling agent. The success of the reaction was highlighted, but lower modification rates were observed. In a third route, a novel approach was successfully proposed for the grafting of thiol molecules on cellulose, based on the click derivatization of the molecule with alkoxysilane functions. Through this study, we expand the modular and versatile character of click chemistry to natural cellulosic substrates. But most importantly, these modification routes can be envisaged for the functionalization of other surfaces (i.e., metal alkoxides for instance) where alkoxysilane chemistry can be employed.
我们研究了三种高效直接的化学途径,首次将烷氧基硅烷化学与硫醇-烯反应的光化学版本相结合,对固体纤维素基材进行功能化。反应的成功通过FTIR-ATR光谱和XPS分析得到证实,但根据所使用的组合,观察到不同的接枝效率。在第一种途径中,烯官能化纤维素膜使用乙烯基三甲氧基硅烷作为偶联剂合成,并与甲基硫代乙醇酸(MeGlySH)进行光化学偶联。在最初的5分钟内,观察到该反应的反应速率非常快。在第二种途径中,通过在硫醇官能化纤维素表面点击烯丙基丁酸酯,设想了相反的反应,该反应先前使用3-巯基丙基三甲氧基硅烷作为偶联剂合成。反应的成功得到了强调,但观察到较低的改性率。在第三种途径中,基于烷氧基硅烷官能化分子的点击衍生化,成功地提出了将硫醇分子接枝到纤维素上的新方法。通过这项研究,我们将点击化学的模块化和多功能特性扩展到天然纤维素基材。但最重要的是,这些改性途径可以设想用于其他表面的功能化(例如金属烷氧化物),其中可以使用烷氧基硅烷化学。