Explore the vast range of titles available.

The purpose of the present work was to prepare polypropylene (PP) matrix composited filled with chemically treated pistachio shell particles (PTx), and evaluate their effect on the composites’ thermal properties. PP-PTx composites were formulated in different PTx content (from 2 to 10 phr) in a mixing chamber, using the melt-mixing process. The PTx were chemically treated using a NaOH solution and infrared spectroscopy (FTIR). According to thermogravimetric analysis (TGA), the treatment of pistachio shell particles resulted in the remotion of lignin and hemicellulose. The thermal stability was evaluated by means of TGA, where the presence of PTx in composites showed a positive effect compared with PP pristine. Thermal properties such as crystallization temperature (Tc), crystallization enthalpy (∆Hc), melting temperature (Tm) and crystallinity were determinate by means differential scanning calorimetry (DSC); these results suggest that the PTx had a nucleation effect on the PP matrix, increasing their crystallinity. Dynamic mechanical analysis (DMA) showed that stiffness of the composites increase compared with that PP pristine, as well as the storage modulus, and the best results were found at a PTx concentration of 4 phr. At higher concentrations, the positive effect decreased; however, they were better than the reference PP.

Lignocellulosic waste materials are among the most abundant raw materials on Earth, and they have been widely studied as natural additives in materials, especially for polymer composites, with interesting results when it comes to improving physiochemical properties. The main components of these materials are cellulose, hemicellulose, and lignin, as well as small amounts of other polysaccharides, proteins, and other extractives. Several kinds of lignocellulosic materials, mainly fibers, have been evaluated in polymer matrices, and recently, the use of particles has increased due to their high surface area. Garlic is a spice seed that generates a waste husk that does not have applications, and there are no reports of industrial use of this kind of lignocellulosic material. Additive manufacturing, also known as 3D printing, is a polymer processing technique that allows for obtaining complex shapes that are hard to obtain with ordinary techniques. The use of composites based on synthetic polymers and lignocellulosic materials is a growing field of research. In the present work, the elaboration and evaluation of 3D-printed polypropylene–garlic husk particle (PP-GHP) composites are reported. First, the process of obtaining a filament by means of a single extrusion was carried out, using different GHP contents in the composites. Once the filament was obtained, it was taken to a 3D printer to obtain probes that were characterized using differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) was performed with the aim of evaluating the thermal behavior of the 3D-printed PP-GHP composites. According to the obtained results, the crystallization process and thermal stability of the PP-GHP composites were modified with the presence of GHP compared with pristine PP. Dynamic mechanical analysis (DMA) showed that the addition of GHP decreased the storage modulus of the printed composites and that the Tan δ peak width increased, which was associated with an increase in toughness and a more complex structure of the 3D-printed composites. X-ray diffraction (XRD) showed that the addition of GHP favored the presence of the β-phase of PP in the printed composites.

In recent years, the use of waste materials from agricultural sources has attracted interest as a research field. Several kinds of waste particles have been studied as additives for asphalt modification, and good results in terms of rheological and physical properties have been discussed in recent literature. In the present work, two types of seed shell particles were evaluated as asphalt modifiers. The shells of Jatropha curcas and pistachio are considered waste materials with no further industrial applications; therefore, in this study, they were incorporated into asphalt at different concentrations in order to evaluate their effect on the binder’s properties. Modified asphalt mixtures were prepared through the hot mix method, and the physical, rheological, and thermal properties of the modified samples were measured and compared to those of the unmodified binder. According to the results of softening point, viscosity, and rheological characterization, the particles obtained from Jatropha curcas and pistachio shells can be used as efficient additives for asphalt modification. Pistachio shell particles act as an asphalt modifier, while Jatropha curcas behaves more like a filler agent since using it at high concentrations causes an inverse effect on the modified performance and properties of the asphalt. Finally, the results obtained showed that both shell particles were useful for improving the binder’s resistance to rutting and permanent deformations, compared to the pure asphalt’s original behavior.

Currently, acne in adolescents and adults is caused by an infection in follicles caused by hormonal changes, stress, water pollution, air, and earth; the last one comes into contact with the skin through the hands of patients. This project presents the incorporation of acetylsalicylic acid (ASA) to the hydroxyethylcellulose/polyacrylamide gel (HEC/PAAm) in the synthesis of gel or by its swelling. The results show us that the incorporation of ASA is possible by both methods; first, the incorporation by synthesis of degradation of the gel is more visible. The infrared spectroscopic analysis shows the functional groups of gel and ASA, 2921 and 2863 cm−1, whose assignments correspond to CH3 and CH2 groups, which are part of both the polymer and the ASA molecule, which confirms the interaction between the two groups. The microscopy photographs (SEM) show on the surface the drug in irregular whitish orthorhombic forms due to swelling; arborescent structures are observed in the case of the incorporation of the ASA drug by synthesis. Swelling kinetics has a Fickian form. The Higuchi model conforms to the release of ASA because the level of confidence is 90%. This gel was allowed to release 0.35 mg/hour, thus allowing the patient to have a continuous form of the release, in the affected area in a short period of time.

In the present work, a reaction methodology was implemented using a batch reactor, which synthesized glycerol carbonate (GC) using glycerin and CaCO 3 . A crystallographic analysis of CaCO 3 was performed to determine its crystalline form. The obtained product was characterized by infrared spectroscopy, thermogravimetric analysis and nuclear magnetic resonance ( 1 H and 13 C). Our analysis demonstrated that the obtained product with the implemented reaction methodology has GC, FTIR showed the signals of the carbonyl groups, and the NMR spectrum confirmed the presence of cyclic carbonate structure in addition to linear carbonates. The thermogravimetric study showed that the thermal stability of the product is highly similar to that reported for GC. These results exhibit that the synthesis process produces linear and cyclic carbonates.

With TEMPO oxidation, it was possible to incorporate iron nanostructures into a cellulose nanofiber matrix. FTIR spectra showed the functional groups present in the films. The combination of both iron and CNF confers to the films good electrochemical activity; the electrochemical characterization (CV) showed that they present stability in the reduction process at a potential of 0–1 V, with the materials with 5% and 10% being the most active. The Pb reduction process shows that the 5% film is the material with the highest oxidizing capacity.

In the present work, the evaluation of chicken feather particles (CFP) and styrene-butadiene/chicken feather (SBS-CF) composites as modifiers for asphalt binder is presented. It is well known that elastomers are the best asphalt modifiers, because their thermoplastic behavior assists asphalts in improving the range of their mechanical properties at both low and high temperatures. Nowadays, the use of natural products and byproducts as fillers for polymer matrices has been a matter of research, and the field of asphalt modification is not the exception. Chicken feather particles (CFP) is a waste material whose main component is keratin, which offers remarkable properties. In the present work, CFP was used as a filler of a styrene-butadiene rubber matrix (SBS) with radial structure, to obtain a composite intended as an asphalt modifier. Besides, raw CFP was also tested as an asphalt modifier. Physical, thermal and rheological properties of the modified asphalts were evaluated in order to determine their degree of modification with respect to the original asphalt. The results show that the addition of raw CFP improves some physical properties as penetration and decreases the phase separation; furthermore, the asphalt modified with CFP displayed similar rheological properties to those shown by the asphalt modified with SBS, while some other properties resulted in being even better, like the phase separation, with the advantage that the CFP comes from a natural waste product.

In the present work, a reaction methodology was implemented using a batch reactor, which synthesized glycerol carbonate (GC) using glycerin and CaCO . A crystallographic analysis of CaCO was performed to determine its crystalline form. The obtained product was characterized by infrared spectroscopy, thermogravimetric analysis and nuclear magnetic resonance ( H and C). Our analysis demonstrated that the obtained product with the implemented reaction methodology has GC, FTIR showed the signals of the carbonyl groups, and the NMR spectrum confirmed the presence of cyclic carbonate structure in addition to linear carbonates. The thermogravimetric study showed that the thermal stability of the product is highly similar to that reported for GC. These results exhibit that the synthesis process produces linear and cyclic carbonates.