Cellulosic surfaces endowed with chemical reactivity by physical adsorption of functionalized polysaccharides

Abstract

Abstract A strategy to functionalize cellulosic surfaces through physical adsorption of xyloglucan (XG) and carboxymethyl cellulose (CMC) derivatives bearing allyl or alkyne groups is reported. A set of functional polymer derivatives with degrees of substitution -DS- ranging from 0.4 to 0.44 are first prepared through epoxide ring opening of allyl glycidyl ether (AGE) or propargyl glycidyl ether (PGE) under mild basic aqueous medium. Contrary to alkyne-based materials, radical copolymerization allyl-XG or -CMC derivatives with acrylamide/acrylic acid leads to the formation of hydrogels confirming thereby their reactivity. Investigations into the deposition of these derivatized polysaccharides on Whatman paper and wood pine fibers further (spraying aqueous solutions, drying and desorption step in water) show that physisorption of the chains is not altered by the DS or by the nature of the anchored groups. QCM-D measurements highlight a high affinity of Allyl-XG for cellulose surface. Confocal Raman mapping of cellulosic substrates modified with alkyne derivatives indicate that the surface covering is quantitative and that the diffusion of the chains within the substrate can reach 40 µm. This aqueous functionalization/spraying procedure is a promising method to confer new ajustable properties to a range of cellulosic substrates in an eco-sustainable manner.