Synthesis of bio‐based internal and external cross‐linkers based on tannic acid for preparation of antibacterial superabsorbents

Abstract

Recent researches focus on the synthesis of new cross‐linkers from natural resources. In the current work, functionalized tannic acid was employed as a replacement of petroleum‐based cross‐linkers because of its outstanding biochemical properties. Alkene‐ and epoxy‐functionalized tannic acids were synthesized as internal and external cross‐linkers, respectively. Cross‐linker structures were characterized with Ft‐IR and 1HNMR analysis. Different amounts, as well as different numbers of alkene functional group, were incorporated during the superabsorbent synthesis. Moreover, the internal cross‐linked superabsorbent was surface cross‐linked with different amounts of epoxy‐functionalized tannic acid and increased the absorbency under load about 10 g g−1. Free absorption properties in water and saline solution, absorbency under load, and rheological properties of superabsorbents were investigated. In addition, the antibacterial activity of the internal and external cross‐linked superabsorbent was studied against Escherichia coli and Staphylococcus aureus bacteria via different methods and compared with that of conventional superabsorbent.

Tannic Acid with Antiviral and Antibacterial Activity as A Promising Component of Biomaterials—A Minireview

“…Tannic acid (TA; Figure 1 ) is a natural tannin from the phenolic acid group and consists of a central glucose unit and ten gallic acid molecules attached to it [ 22 ]. It may be isolated from both herbaceous and woody types of plants [ 23 ]. TA is one of the main examples of tannins which can be efficiently extracted from natural sources with high efficiency, and thus, it attracts much scientific interest.…”

“…Dabbaghi et al [ 23 ] have reported the tannic acid activity against Staphylococcus aureus and Escherichia coli which dependend on the phenolic hydroxyl groups content. Tannic acid was used as a polymer cross-linker, and final hydrogels showed antibacterial activity against both types of bacteria in the case of which the increased activity was related to increasing content of TA in the material.…”

“…Gram-positive bacteria are easier to kill. Gram-negative bacteria are not destroyed by certain detergents which easily kill Gram-positive bacteria [ 23 ].…”

“…Gram-negative bacteria are more harmful and cause certain diseases; so, the examination of this group of bacteria is especially required. Tannic acid has been studied against different types of bacteria so far, both, Gram-positive (mainly Staphylococcus aureus ) as well as Gram-negative ones (mainly Escherichia coli ) [ 23 , 34 , 47 , 48 , 49 ].…”

The Influence of Monomer Composition and Surface-CrossLinking Condition on Biodegradation and Gel Strength of Super Absorbent Polymer

“…The rheological properties were measured at 25 °C after placing the expanded gel particles on a parallel plate of a rheometer. The storage modulus (G′) and loss modulus (G″) were recorded at constant shear strain (0.2%) and a frequency ranging from 0.1–100 Hz [ 39 ].…”