Isocyanate‐Free, UV‐Crosslinked Poly(Hydroxyurethane) Networks: A Sustainable Approach toward Highly Functional Antibacterial Gels

Abstract

An increased sustainabile awarness has inspired the development of new polymeric networks in a remarkable way and this strive should be combined with environmentally concerned end-uses. Therefore, a UV-crosslinked polyhydroxyurethane film with antibacterial properties is developed. First, a hydroxyurethane precursor is synthesized using aminolysis condensation, circumventing the use of isocyanates. The films are subsequently crosslinked under solvent-free conditions through a UV-triggered thiol-ene mechanism. The reactions are monitored by H nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy, and the networks have gel contents above 90%, and are transparent, hydrophilic, and highly flexible. Antibacterial properties are achieved by a controlled quaternization of the network's tertiary-amine and methylation of thiol-ether functionality, resulting in quaternary ammonium compounds (QACs) and sulfonium compounds. The antibacterial properties are evaluated against both Escherichia coli and Staphylococcus aureus using the agar plate diffusion and tube shaking methods. The QAC-loaded films exhibit outstanding bactericide properties (>99.9%) and the antibacterial mechanism is demonstrated to be a dual killing mechanism, i.e., diffusion killing and contact active killing.

Design of Plurifunctional Cyclocarbonates and their Use as Precursors of Poly(hydroxyurethane) Thermosets: A Review

“…However, some chemically activated monomers appear to be reactive enough in mild temperature conditions. Examples of syntheses of thermosetting PHUs at moderate temperature from 5CC [78,[106][107][108][109] but also from 6CC [8,52,63,106,[110][111][112] and 8CC [113] precursors are described in the literature and are presented hereafter (Figure 21).…”

Anionic polycondensation and equilibrium driven monomer formation of cyclic aliphatic carbonates

“…The depolymerization method and setup has previously been reported. 47,48 For a typical depolymerization, 80 g of DEC (0.67 mol, 1.4 eq.) was charged into a 250 mL round bottom ask equipped with a magnetic stirring bar.…”

Preparation and Evaluation of Antimicrobial Hyperbranched Emulsifiers for Waterborne Coatings

“…Low-molecular-weight cationic surfactants, such as cetyl­tri­methyl­ammonium chloride, are well-known potent biocides but have poor emulsifying properties. As a result, only low monomer concentrations can be used, along with high biocide concentrations. − The incorporation of quaternary ammonium comonomers in coating resins, such as in polyacrylates and polyurethanes, has been described often, giving biocidal and emulsifying properties. − However, in these cases the coating properties will be influenced as well because the cationic moieties are randomly distributed throughout the whole coating resin. In contrast, only a very few attempts have been reported for preparing antibacterial polymeric emulsifiers that will be located only at the periphery of the paint droplets, without influencing the coating properties.…”