Evaluation of Physicochemical and Amphiphilic Properties of New Xanthan Gum Hydrophobically Functionalized Derivatives

Abstract

This research aimed to develop new hydrophobic and potentially amphiphilic benzyl xanthan gum (BXG) derivatives using a Williamson synthesis. This modification consists of an etherification reaction between xanthan gum (XG) and benzyl chloride (BC) under microwave heating. The effects of the molar ratio (R = XG/CLB, with R equal to 2 or 4) on the amphiphilic character and the degree of substitution (DS) were studied. The two benzyl xanthan gum derivatives (BXG1 and BXG2) were subsequently subjected to various physicochemical and rheological characterization techniques. The obtained results of FTIR and H1-NMR spectroscopy showed the effectiveness of the grafting of aromatic moieties onto the XG molecule with DS values of 0.59 for BXG1 and 0.7 for BXG2. The XRD analysis revealed slight modifications in the xanthan crystallinity after etherification, where the degree of crystallinity (DOC) values were 8.46%, 10.18%, and 14.67% for XG, BXG1, and BXG2, respectively. Additionally, conductivity measurements showed that the BXG derivatives exhibit higher values than native XG, due to the inter- and intra-molecular associations following the grafting of aromatic groups. Moreover, the critical aggregation concentration (CAC) was detected at 0.32% for BXG1 and 0.28% for BXG2. The rheological study confirmed that XG and its BXG derivatives exhibited a shear-thinning pseudoplastic behavior and that the viscosity increases when the DS increases. The emulsifying power test of the BXGs compared to the native XG confirmed the amphiphilic properties of the new benzylated derivatives, where the stabilizing capacity increases with increased DS.

Microwave‐modified xanthan gum: Alterations in steady and dynamic rheological behaviors

“…This peak became narrower over time, particularly after the 720 W-6 min, however, the peak intensity increased compared to 960 and 1200 W, despite a reduction in the amount of water. The reduced intensity of this signal in treated XG samples at 960 and 1200 W could possibly be ascribed to OH group substitution (Yahoum et al, 2023). The broadening of this peak and its shift to a lower wavenumber with modification implies a gradual increase in the intermolecular hydrogen bonding between the molecules (Solo- de-Zaldívar et al, 2014).…”

Xanthan–Polyurethane Conjugates: An Efficient Approach for Drug Delivery

“…The novelty in combining these base materials lies in leveraging the complementary properties of xanthan and polyurethane to address the known challenges of rapid degradation and poor mechanical strength found in conventional materials [31,54]. Furthermore, the esterification of xanthan with oleic acid for controlled drug release is a novel approach, enhancing the hydrophobic interactions and thus the structural integrity of the polysaccharide in humid conditions, as supported by recent literature [55,56]. This innovative combination potentially broadens the application spectrum of these biomaterials, particularly in the dermato-cosmetic domain, providing a new avenue for the controlled release of ketoconazole and piroxicam.…”

Formulation and Characterization of Double Emulsions W/O/W Stabilized by Two Natural Polymers with Two Manufacturing Processes (Comparative Study)

“…The stabilization of multiple emulsions commonly involves the synergistic use of hydrophilic and hydrophobic surfactants [27][28][29]. Surfactants with a low Hydrophilic Lipophilic Balance (HLB) are employed to stabilize the internal emulsion [30], while those with a high HLB are employed for the outer emulsion [6].…”