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Active coatings have been extensively studied due to their ability to contain active substances that can promote ab/adsorption and/or catalysis of compounds of interest. In this work, solution blow spraying (SBSp), which is a modification of the solution blow spinning (SBS), was used to produce active coatings via a multistep process: The first stage consisted in applying a cross‐linkable polymer layer (epoxy) to a metallic substrate, followed by heating at 50°C to promote partial cross‐linking; in the second step, particle suspensions containing zinc oxide (ZnO) and/or bentonite/ZnO were sprayed over the resin layer so that particles adhered to the surface rather than embedded in, what would reduce surface activity. Primarily, rheology of the suspensions and resin cure were characterized by rheometry and differential scanning calorimetry (DSC), respectively. Infrared spectroscopy and scanning electron microscopy of the ZnO synthesized by the Pechini method was performed. Coatings were analyzed by optical microscopy (OM), scanning electron microscopy (SEM), and x‐ray diffraction (XRD). Based on the suspension studies, the optimized particle concentration was found to be 10 wt% in water. Thermal analysis of resin showed the ideal time and temperature of 16 min or 33 min at 50°C. Using these variables, active coatings with ZnO and bentonite/ZnO particles exposed to the surface were successful produced by SBSp. [ABSTRACT FROM AUTHOR]

Fresh produce have a more limited shelf life than processed ones. Their sensory attributes such as appearance and surface texture are important features in consumer perception and liking. The decomposition of fresh produce, which is caused by enzymes, chemical reactions, and microbial infections, often caused by Colletotrichum species, is inevitable. However, it can be slowed down. Several materials have been developed for this purpose, with an emphasis on active coatings using nanomaterials. In this study, the protective effects of a zein coating containing chitosan nanowhiskers (CSW) for the maintenance of fruit quality were investigated using guava (Psidium guajava L.) as a model fruit. CSW were previously characterized, and their antifungal effects against distinct Colletotrichum species (Colletotrichum asianum, Colletotrichum tropicale, Colletotrichum gloeosporioides, and Colletotrichum brevisporum) were proven. Coatings were characterized by thermogravimetric analysis, optical profilometry, and mechanical properties. Total soluble solids, pH, mass loss, and visual inspection of uncoated and coated guava fruits were also verified during 9 days. Results show that CSW length and aspect ratio decreased for longer extraction times. A similar behavior was found for x‐ray diffraction in which peak intensity decreases under the same conditions. CSW degradation (ca. 250–400°C) also depends on extraction time in which more crystalline whiskers are the most thermally stable ones. The addition of CSW did not significantly (p < 0.05) modify the homogeneity and continuity of coating but prevented microbial growth assuring fruit quality during storage. In summary, coatings protected guava fruits from post‐harvest spoilage while preserving quality and extending shelf life. Practical Application: Fresh foods such as fruits and vegetables have a more limited shelf life than processed ones. [ABSTRACT FROM AUTHOR]

Although the consequences of adhesive residues from post-consumer Poly(ethylene terephthalate) (PET) beverage bottles on the performance of recycled products are known, the quantitative effects of these adhesives are not well-stablished in the literature. Therefore, these residues were determined by gravimetry, and the adhesive content range from 200 to 2800 ppm in post-consumer PET bottles, depending on the drink filled. Through FTIR analysis, it was determined that the adhesives for bottles labelling are composed by poly(ethylene- co -vinyl acetate) (EVA). Based on these results, recycled PET with 0, 200, 700, 1500 and 3000 ppm of hot-melt EVA were processed in an internal mixer connected to a torque rheometer at 265°C for 10 min. Tensile tests indicate that 200 ppm of adhesive reduced PET tensile strength by 15%. Furthermore, when about 1500 ppm of adhesive is present, PET mechanical properties are reduced by 50%. Therefore, it is of utmost importance to warn the PET bottle production chain to reduce adhesive content used in labelling so that it should not exceed 200 ppm, if a high quality recycled PET is desirable. Graphical Abstract [ABSTRACT FROM AUTHOR]

Epoxidized soybean oil (ESO) compounds were cured with methyl tetrahydrophthalic anhydride (MTHPA) as hardener and 2,4,6‐tris (dimethylaminomethyl) phenol (DEH 35) as catalyst. To figure out MTHPA and DEH 35's influence during curing and degradation, ESO/MTHPA/DEH 35 compounds were investigated using Fourier‐Transform Infrared Spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetry (TG). FTIR spectra of uncured resin showed the secondary interactions among ESO's carbonyl groups with MTHPA and DEH 35's hydroxyls and amines. Curing progress was followed tracking the evolution of reactive groups, that is, epoxy and carbonyl bands and corroborated with released heat of DSC scans. ESO 87:5 and ESO 87:10 compounds cured using higher heating rates presented higher released enthalpy suggesting denser reticulation, and they also displayed lower activation energy Ea for curing, which was evaluated using the Friedman model. Increasing the hardener and catalysts contents promoted higher thermal stability and lower degradation rates, while higher Ea for degradation was verified. [ABSTRACT FROM AUTHOR]

Abstract: The effect of relative humidity on the morphology of electrospun fibers of poly(vinyl alcohol), poly(methyl methacrylate), poly(vinyl chloride), polystyrene, and poly(lactic acid) dissolved in solvents such as toluene, N,N-dimethylformamide, [...]