Unexpected Plasticization Effects on the Structure and Properties of Polyelectrolyte Complexed Chitosan/Alginate Materials

Abstract

This work describes the effects of different plasticizers, namely, glycerol, triacetin, and 1-ethyl-3-methylimidazolium acetate ([C 2 mim][OAc]), on the structure and properties of thermomechanically processed, bulk chitosan and chitosan/alginate materials. Mechanical data shows that, for the chitosan matrix, glycerol and [C 2 mim][OAc] were highly effective at reducing intra- and intermolecular forces between biopolymer chains, leading to increased ductility, while the plasticization effect of triacetin was minor. Nonetheless, this triester effectively suppressed biopolymer recrystallization, whereas [C 2 mim][OAc] promoted it. In contrast, for the chitosan/alginate matrix, inclusion of triacetin resulted in increased recrystallization, higher thermal stability, and excellent mechanical properties. The triacetin assisted the interactions between biopolymer chains in this polyelectrolyte complexed system. In contrast, the chitosan/alginate material plasticized by [C 2 mim][OAc] displayed the most apparent phase separation, poorest mechanical properties, and highest surface hydrophilicity, behavior associated with the disruption of polyelectrolyte complexation and hydrogen bonding between biopolymer chains. Interestingly, the formation of a “new structure” under the electron beam during microscopy imaging was observed, likely from coordination between alginate and [C 2 mim][OAc]. Thus, this work has revealed the strong and unexpected effects of three different plasticizers on the hydrogen bonding and electrostatic interactions within chitosan/alginate polyelectrolyte complexed materials, which have potential for biomedical applications where balanced hydrophilicity and mechanical properties are required.

Turning Toxic Nanomaterials into a Safe and Bioactive Nanocarrier for Co-delivery of DOX/pCRISPR

“…After treatment with the alginate-based carriers, the uptake of drug was decreased considerably in comparison to the chitosan-based carriers, presumably because of occupying the receptor of folate on the surface of the cells. There are several studies in the literature on using chitosan- and alginate-based nanocarriers in drug delivery systems; however, most of them suffer from unwanted aggregations between the nanocarriers. , These aggregations come from high concentrations of the used chitosan and alginate and/or high molecular weight of these natural polymers. , In order to bypass these problems, it would be better to use the independent nanocarriers to the polymeric structure. It means using nanocarriers that are not dependent on the polymeric structures to perform their application.…”

“…84,85 These aggregations come from high concentrations of the used chitosan and alginate and/or high molecular weight of these natural polymers. 86,87 In order to bypass these problems, it would be better to use the independent nanocarriers to the polymeric structure. It means using nanocarriers that are not dependent on the polymeric structures to perform their application.…”

Polyelectrolyte Complexation of Chitosan and WS2 Nanotubes

“…The change in the XRD pattern of processed chitosan in comparison to that of the unprocessed chitosan powder is from the processing with acetic acid almost fully destroying the original chitosan crystalline structure and, subsequently, new crystals were formed. [48,61] The impact of inclusion of the WS 2 NTs on the crystalline behavior of chitosan can be seen in Figure 6a). Characteristic peaks of WS 2 NTs can be observed at 2𝜃 = 14.2°( 002), 28.7°(004) and 33.4°(101), and as expected, the intensity of these peaks increases with increasing WS 2 NT content.…”

Environmentally Friendly Melt-Processed Chitosan/Starch Composites Modified with PVA and Lignin

“…Chitosan-based films and coatings have been recently intensively studied [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. Most of the research has been focused on evaluating different preparation conditions (including the processing method) and incorporation of additives to improve the properties of composites.…”

“…However, the plasticization of chitosan is necessary before applying this method. Glycerol, sorbitol, and xylitol are frequently used as plasticizers, and their presence provides thermoplastic material with good mechanical properties [ 19 , 20 , 21 , 22 ]. Furthermore, thermomechanical processing allows the use of the conventional tools for polymer processing, such as extruders, kneaders, injection molding, etc., enabling the production of a wide variety of forms and shapes in contrast to a wet method, in which only casted films are produced.…”