Grafting of pyrrole onto cellulosic lyocell fibres via (3-chloropropyl)triethoxysilane anchor

Abstract

The high number of reactive groups present in the cellulose structure form the chemical basis for chemical derivatisation through many different chemical pathways. Silane anchors are available with a variety of moieties that offer many functionalisation options of cellulose fibres. It is therefore important to investigate the deposition and grafting of silanes on such substrates. In this paper, the grafting of (1-(3-(triethoxysilyl)propyl))-1H-pyrrole (PySi) onto a cellulosic lyocell fibre based textile was investigated. Depending on the amount of silane applied, a maximum amount of 0.09 mmol PySi/g cellulose was observed to form covalent bonds with the cellulose lyocell fibres. A maximum of 0.36 mmol PySi/g cellulose was deposited on the fibre substrate, of which 0.27 mmol could be removed by solvent extraction. The results can be explained by a limited number of binding sites available on the cellulose surface suited for covalent bond formation with PySi. In addition, a simple method for quantifying the amount of silane on cellulose fibres using thermogravimetric analysis (TGA) is presented. The results found for the behaviour of PySi on cellulose material contribute to a better understanding of the heterogeneous modification of cellulose.