In this study, porous microspheres of TiO 2 (µTiO 2) were synthesized, characterized and incorporated into an acrylic paint formulation to obtain a photocatalytically active paint. In a novel approach, the antifungal properties of the µTiO 2 paint were evaluated using Monascus ruber as the representative microorganism and compared to those of a photocatalyst-free paint. The photocatalytic activity of paint films was determined by methylene blue (MB) degradation under real conditions of application. High photocatalytic and antifungal activity was observed, with the microorganism culture showing the formation of growth inhibition halos, typical of materials that produce biocides that diffuse into the culture medium.

This study presents an experimental essay on the production of thermoplastic polyurethanes for flexographic printing ink applications. Four formulations were obtained by step‐growth polymerization reactions having the pre‐polymer 4,4′‐diphenylmethylene diisocyanate and Voranol 2120 L® catalyzed by dibutyltin dilaurate as common ground. In the chain extension step, ethanol or ethyl acetate was used as solvent, and the use or not of castor oil as a chain extender in addition to hexanedioic acid and 2,2′‐oxydi(ethan‐1‐ol) was evaluated. The chemical structures of the synthesized thermoplastic polyurethanes (TPUs) were evaluated by Fourier transform infrared spectroscopy, 1H NMR, gel permeation chromatography, differential scanning calorimetry, and rheological features were assessed by density and viscosity analysis. The TPU resins were used to produce flexographic printing inks and further tested by friction, adhesion, gloss, and Gardner viscosity essays. It was found that the castor oil presence enhanced ink viscosity in 66% (from 26,790 to 44,440 Pa s) as well as improved strength. Formulations using ethanol as solvent showed the best results. The experiments were carried in a 250 ml reactor and then, scaled up to 2000 ml, keeping the power transfer per unit of volume constant at around 0.8 W/L. The analytical results from the larger scale were as good as the obtained in scale one, showing promising application.

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/mren.201900009. Thermochromic FilmsThermosensitive-thermochromic pigments are classified as smart materials capable of detecting and/or responding to environmental stimuli, and specifically in this study, changes in temperature that induce a change in the color of the material. This study aims to obtain nanoparticles of poly(styrene-co-butyl acrylate) and poly(styrene-co-methyl methacrylate), containing thermosensitivethermochromic pigments that are incorporated into the monomer droplets in miniemulsion polymerization. Miniemulsion polymerization has the advantage that the pigment particles can be dispersed directly in the monomer droplets and are encapsulated when the miniemulsion droplets are polymerized. Using controlled/living radical polymerization (or Reversible Deactivation Radical Polymerization), it is possible to produce polymers with better control of microstructure and narrower molecular weight distributions. Nitroxide-mediated polymerization (NMP) is conducted using the BlocBuilder initiator, as well as a conventional free radical polymerization (FRP) using potassium persulfate (KPS) and 2,2-azobis(2-methylpropionitrile) (AIBN). Stable latexes containing the thermosensitive-thermochromic pigments are obtained by both NMP and FRP. Films are made from the latexes and shown to exhibit thermochromic behavior.

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