Preparation of crosslinked chitosan/poly(vinyl alcohol) blend beads with high mechanical strength

Abstract

Crosslinked chitosan beads reported in the literature have the disadvantage of high water content and thus low mechanical strength. In this paper, a chitosan/poly(vinyl alcohol) (PVA) blend aqueous solution was first suspended in toluene-chlorobenzene to form droplets. Some of the water was then distilled out as an azeotrope with the aromatic hydrocarbons to reduce the water content of the suspension droplets. Glutaraldehyde was finally added to the suspension to result in the crosslinked chitosan/PVA beads with low water content and high mechanical strength. It was found that glutaraldehyde reacted with PVA to form crosslinkage at acidic conditions (pH 1 and 2). The H + ions act as both protection agents of amino groups of chitosan by forming salts and catalyst for the formation of acetal between aldehyde groups and hydroxyl groups of PVA. At pH 4 and 5, glutaraldehyde reacted with chitosan to form Schiff's base crosslinkage. Crosslinked chitosan/PVA beads with micron size were also prepared by the distillation method using very dilute initial polymer concentration and high stirring speed. Preparation of crosslinked chitosan/PVA blend beadsChitosan solution (4.0%, w/w) was prepared by dissolving 4.2 g of chitosan into 100 g of dilute acetic acid (2% w/w). PVA solution (12.5%, w/w) was prepared by dissolving 14.3 g of

Creation of regenerated cellulose microspheres with diameter ranging from micron to millimeter for chromatography applications

“…In addition, the mechanical intensities of the microspheres were better, and could be enhanced by cross-linking with cross-linking agent (e.g. glutaraldehyde, epichlorohydrin, ethylene glycol glycidyl ether, etc) [49] to expand its applications at higher pressure.…”

Immobilization of Naringinase in PVA–Alginate Matrix Using an Innovative Technique

“…They were then soaked in acetate buffer maintained at 4°C and again weighed, following removal of excess buffer with filter paper, after 18 h (W s ). The swelling ratio was determined according to [33,34]:…”

Effective dispersion and crosslinking in PVA/cellulose fiber biocomposites via solid-state mechanochemistry

“…Chabba et al crosslinked soy flour/flax yarns composites using glutaraldehyde (GA) as the crosslinking agent to improve the tensile and thermal properties [19]. Li et al also used GA to prepare crosslinked chitosan/PVA blend beads with high mechanical strength [20]. Teramoto et al reported that the miscibility and mechanical properties of pullulan/PVA composites were significantly improved after being crosslinked with glyoxal [21].…”