Synthesis of allyl cellulose in NaOH/urea aqueous solutions and its thiol–ene click reactions†
Allyl celluloses (ACs) were synthesized by the reaction of cellulose with allyl chloride in NaOH/urea aqueous solutions. The reaction started homogeneously and ended heterogeneously. The structure and properties of ACs were characterized with SEC-LLS, NMR and solubility testing. The results demonstrated that organo-soluble AC, with a degree of substitution of 0.98–1.65, could be obtained by adjusting the molar ratio of allyl chloride to the anhydroglucose unit of cellulose. A capability evaluation of the click reaction of AC was performed by selecting four thiol compounds. AC-click products were characterized with FT-IR, NMR and elemental analysis, and the results indicated few impurities or substructures resulting from side reactions. The click reaction displayed a high conversion rate, and all the AC-click products demonstrated high solubility in certain solvents. This work provides a facile method for the synthesis of AC in an aqueous system and shows a novel stage for the mild and diverse derivatization of cellulose.