Explore the vast range of titles available.

The intensive use of chemical fertilizers has degraded soil ecosystems, emphasizing the need for sustainable alternatives like biofertilizers. This study evaluated the interaction between hydroxyapatite (HAp) derived from eggshells and bovine biol produced under anaerobic conditions. HAp was synthesized by calcination at 900 °C and impregnated with biol under constant agitation for 24 and 48 h. Characterization by FTIR and XRD confirmed preservation of HAp functional groups—phosphate (960–1030 cm −1 ), carbonate (∼1500 cm −1 ), and hydroxyl (3570 cm −1 )—and crystalline peaks within 2θ = 30°–50°, without new phase formation. The absence of structural or functional modifications indicates limited HAp–biol interaction, likely due to reduced porosity from high-temperature calcination. These findings highlight the need to optimize HAp synthesis to enhance organic compound retention in controlled-release biofertilizers.

Asphalt performance improves with the incorporation of various additives and with the time factor. In this study, the effect of time on asphalt mixtures (AM) containing styrene–butadiene–styrene (SBS) and sargassum particles (SGP) is analyzed. The composites were prepared by the melt method, using five part hundred rubber (phr) of SGP and polymeric matrices of SBS with low and high vinyl content. The asphaltic mixtures were made with 3% percent by weight (wt%) of these composites, identified as high vinyl asphalt mix (AMH) and low vinyl asphalt mix (AML), respectively. Temperature sweep tests were carried out within linear viscoelastic region (LVR), with measurements taken at 1, 7, 14, and 82 days after mixing. The parameters studied include the viscoelastic behavior in the black diagrams, the effect of heavy traffic on the isochronous comples modulus-phase angle-temperature (G*)–δ–T curves, and the rutting factor with the parameter complex modulus between delta sine (G*/sin δ). In conclusion, the AMH asphalt mix shows the best rheological performance after 82 days of mixing. Graphical abstract

The reinforcement of polymers with vegetal fibers is experiencing important advances in both its properties and processing as well as in its acceptance by the consumer, maintaining an exponential growth in terms of development and innovation in new composite materials. The focus of this research is given in the study of the potential effect of sargassum particles (SgP) as reinforcement in the thermomechanical properties of a polymeric matrix composed of HIPS and SBS. Three different concentrations of SgP in the matrix 5, 10, and 15 PHR (parts per hundred of additive) were evaluated and compared with a reference of virgin polymers (not modified). The evaluation of the composites in mechanical stress-elongation tests showed results of a Young's modulus higher by 58% with respect to the reference, reaching a maximum value with a content of 15 PHR of particles in the binary matrix. The composites were also evaluated in Fourier transform spectroscopy, as well as in optical microscopy. Graphical abstract

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.

The use of plant waste, such ashusks, fibers, and bagasse, as additives in polymeric matrices generated great interest recently, since they became an option to be used as additives, reinforcers, or only as fillers. The pistachio is a seed for human consumption, while the Jatropha curcas (JC) is a seed from which oils are extracted, and are used to obtain biofuels; however, their shells are not used when discardedbecause no useful application is known.An interesting application for this waste material is to use it as a bioadditive in polymeric matrix. The objective of the present work is to prepare polymer composites with polypropylene (PP) as a matrix and as a bio-additive particle inseed shells, in this case Jatropha curcas shell particles (JA) and pistachio shell particles (PI), in different content from 2 to 10 phr. The composites were characterized by techniques such as differential scanning calorimetry (DSC) and X-ray diffraction (XRD) to evaluate crystallinity; by using thermogravimetric analysis (TGA), the thermal stability was studied, and by using dynamic mechanical analysis (DMA) the viscoelastic behavior of composites was evaluated. According to DSC, results suggest that a nucleating effect occurs with the addition of the JA and PI, which was reflected in an increase in thepercent of crystallinity of the composites. The TGA results show that thermal stability of the composites was modified with the presence of JA and PI, compared with that PP pristine.In addition, dynamic mechanical analysis (DMA) reported that the viscoelastic behavior was modified, findinga higher capacity to dissipate energy for composites, PI being the one that presented a greater effect on them.

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.

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.

The salt of neodymium has been widely used in industrial polymerization of 1,3-butadiene. We used the ternary catalytic system neodymium versatate/diethylaluminum chloride/triisobutylaluminum (NdV3/DEAC/TIBA) with 0.5 mM NdV3/100 g Bd, NdV3 : DEAC = 1 : 9 mol : mol, and TIBA = 25, 50, 100, and 200 mM. The number-average molecular weight (Mn), weight-average molecular weight (Mw), and polydispersity index (PDI) were analyzed by GPC; the rheological properties were analyzed by DMA. The formulations were prepared with carbon black (IRB6) as reinforcing filler and the mechanical properties were compared to behavior of the different elastomeric compounds. The elastomeric compounds were characterized by their rheological properties, tensile strength, abrasion resistance, tear strength, permanent set, resilience, and fatigue properties. The high cis-1,4 polybutadiene (high cis-1,4-BR) was obtained with a percentage of cis-1,4 ≥97%. The weight-average molecular weight (Mw) was from 150 × 103 to 900 × 103 g/mol and polydispersity index (PDI) was from 3.1 to 5.1. This work is based on evaluation of the effect of the catalyst system on the final properties of the synthesized polybutadiene.

The present work evaluates the influence of different properties of composite materials from natural sources. Films were prepared using the evaporative casting technique from corn starch reinforced with a waste material such as garlic husk (GH), using glycerin as a plasticizer. The results of the syntheses carried out demonstrated the synergy between these materials. In the morphological analysis, the compatibility and adequate dispersion of the reinforcer in the matrix were confirmed. Using Fourier transform infrared spectroscopy (FTIR), the interaction and formation of bonds between the matrix and the reinforcer were confirmed by the presence of some signals such as S-S and C-S. Similarly, thermogravimetric analysis (TGA) revealed that even at low concentrations, GH can slightly increase the decomposition temperature. Finally, from the results of dynamic mechanical analysis (DMA), it was possible to identify that the storage modulus increases significantly, up to 115%, compared to pure starch, especially at low concentrations of the reinforcer.