Biocidal polymer coatings based on porphyrin-modified epoxy-amine networks

For the first time, a pronounced biocidal activity of modified polymers with a porphyrin content of 21.4 μM (0.002 wt%) against Staphylococcus aureus was demonstrated. In order to develop new biocidal polymer coatings, a study was carried out on diglycidyl ether of bisphenol A (DGEBA) and porphyrin-modified oligomeric diamine systems. The study investigated the solubility of porphyrins in oligomers through experimental and theoretical means, using Van Krevelen's approach of additive group contributions. Fully cured epoxy-amine polymer materials modified with varied free-base tetraarylporphyrins were obtained. The materials were studied by means of thermogravimetry, differential scanning calorimetry, UV–Vis and fluorescence spectroscopy. The proposed approach to the formation of modified epoxy-amine materials allows preservation of the photophysical properties of porphyrins, including their photostability. The addition of modifiers in 4.28–21.4 μM range of concentrations makes it possible to keep the thermophysical and thermochemical properties of the polymer matrix. [Display omitted] •An approach to obtain fully cured epoxy-amine coatings with tetraarylporphyrins is presented.•The porphyrins have no significant impact on the thermal properties of the polymer matrix.•The porphyrins in an epoxy-amine network are shown to be photostable.•The biocidal activity of the polymers with a 0.002 wt% porphyrin against S. aureus was revealed.