Elimination of inter- and intramolecular crosslinks of phosphorylated chitosan by sodium salt formation

Abstract

Inter-and intramolecular crosslinking is the main cause of the water insolubility of phosphorylated chitosan synthesized with a phosphorus pentoxide/methanesulfonic acid system. The goal of this study was to eliminate inter-and intramolecular crosslinks and synthesize water-soluble phosphorylated chitosan. Two main factors for the formation of inter-and intramolecular crosslinks are (i) electrostatic interaction between amino groups and methanesulfonic acid salt and (ii) electrostatic interaction between ammonium groups and phosphoric groups. The influences of ethanol washing and sodium salt formation on the elimination of inter-and intramolecular crosslinks were investigated. Sodium phosphorylated chitosan was water soluble. The solubility was independent of the degree of phosphoric substitution.

Sodium-phosphorylated chitosan/zinc oxide complexes and evaluation of their cytocompatibility: An approach for periodontal dressing

“…PCTS with a degree of phosphate substitution of 0.6 was synthesized and used in this study. 23 Briefly, PCTS was synthesized though three steps, which were phosphorylation, sodium salt formation, and neutralization. First, chitosan was allowed to react with two mole equivalents of phosphorus pentoxide (P 2 O 5 ) in methanesulfonic acid.…”

“…3 – 5 Recently, our group has synthesized the derivative biocompatible chitosan, sodium-phosphorylated chitosan (PCTS). 23 This material contains the functional phosphate groups (Supplementary data, Figure S1) that could possibly donate protons to the hydroxyl species on the surface of ZnO for complex formation. Therefore, PCTS could possibly replace the toxic polymeric resins that are currently used as reaction rate-modifying agents in periodontal dressings.…”

Perspectives for chitosan‐based membranes in CO2/N2 separation : Structure‐property relationship

“…63,64 The electrostatic attraction between the phosphoric groups and protonated amine groups result in the formation of these linkages. 65,66 Similarly, HPC is another water-soluble chitosan derivative 67,68 which exhibits the ability to form good, smooth films. 69…”

The 21st century revival of chitosan in service to bio-organic chemistry

“…According to Tachaboonyakiat et al [52], the main cause of the water insolubility of phosphorylated chitosan is inter-and intra-molecular crosslinking. Fu and Xiao [53]developed a facile physical approach to make chitosan soluble in acid-free water by modulating the solution concentration and varying the precipitants.…”

“…Due to the semicrystallinity of chitosan, it displays polymorphism which depends on its physical state [48]. Recent scientific investigations [13,30,33,[47][48][49][50][51][52][53][54] outlined strong and complex interdependence between various chitosan functionality parameters and intrinsic/extrinsic factors, which is schematically illustrated in Figure 3.…”