RESUMEN

The environmental emergency has alerted consumers and industries to choose products derived from renewable sources over petroleum derivatives. Natural fibers of plant origin for reinforcing composite materials dominate the field of research aiming to replace synthetic fibers. The field of application of green dog wool composite materials needs to be reinforced and proven, as the industry is looking for more sustainable solutions and on the other hand this type of raw material (pet grooming waste) tends to grow. Hence, in the present work, the feasibility of applying natural fibers of dog origin (mainly composed by keratin) in green composites was studied. The green composites were developed using chemically treated dog wool of the breed Serra da Estrela (with NaOH and PVA) as reinforcement and a green epoxy resin as a matrix. The chemical treatments aimed to improve adhesion between fibers and matrix. The fibers' composition was determined using X-ray Diffraction (X-RD). Their morphology was determined using a scanning electron microscope (SEM). The wettability of the fiber was also evaluated qualitatively by analyzing drops of resin placed on the fibers treated with the different treatments. The mechanical properties of the composites were also studied through mechanical tensile, flexural, and relaxation tests. Overall, the best results were obtained for the dog wool fibers without treatment. The tensile and flexural strength of this biocomposite were 11 MPa and 26.8 MPa, respectively, while the tensile and flexural elastic modulus were 555 MPa and 1100 MPa, respectively. It was also possible to verify that the PVA treatment caused degradation of the fiber, resulting in a decrease in mechanical tensile strength of approximately 42.7%, 59.7% in flexural strength and approximately 59% of the stress after 120 min of relaxation when compared to fiber made from untreated dog wool. On the other hand, the NaOH treatment worked as a fiber wash process, removing waxes and fats naturally present on the fiber surface.

RESUMEN

Wool fiber is a textile material that is highly valued based on its diameter, which is crucial in determining its economic value. To analyze the molecular mechanisms regulating wool fiber diameter, we used a Data-independent acquisition-based quantitative proteomics approach to analyze the skin proteome of Alpine Merino sheep with four fiber diameter ranges. From three contrasts of defined groups, we identified 275, 229, and 190 differentially expressed proteins (DEPs). Further analysis using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways revealed that pathways associated with cyclic adenosine monophosphate and peroxisome proliferator-activated receptor signaling are relevant to wool fiber diameter. Using the K-means method, we investigated the DEP expression patterns across wool diameter ranges. Using weighted gene co-expression network analysis, we identified seven key proteins (CIDEA, CRYM, MLX, TPST2, GPD1, GOPC, and CAMK2G) that may be involved in regulating wool fiber diameter. Our findings provide a theoretical foundation for identifying DEPs and pathways associated with wool fiber diameter in Alpine Merino sheep to enable a better understanding of the molecular mechanisms underlying the genetic regulation of wool fiber quality.

Asunto(s)

RESUMEN

Ethiopia has indigenous breeds of sheep such as Washera, Menz, Farta, and Tikur. Small-scale enterprises are using the wool fibers from these breeds to produce local products such as rugs, socks, sweaters, quilts, and mattresses. This study investigates four Ethiopian sheep breeds wool fiber yield and moisture regain properties. Four hundred total sheep, of which 50% males and 50% female sheep, were included in the study. The result revealed that the average wool fiber yield according to the IWTO CWC standard of male sheep for Washera, Menz, Farta, and Tikur were 89.29%, 88.29%, 73.33%, and 81.74%, and for female sheep were 88.75%, 81.91%, 73.23%, and 80.80%, respectively. The selected Ethiopian wool fiber yield showed higher as compared to other sheep breeds of some countries. The study also revealed that the raw wool fiber moisture regain values of Washera, Menz, Farta, and Tikur were 10.67%, 16.91%, 11.11%, and 10.71% for male sheep and 11.92%, 15.91%, 11.83%, and 9.22% for female sheep, respectively. This shows that the Ethiopian wool fiber having good fiber yield and moisture regain can be used as a source of manufacturing different wool products.

Asunto(s)

RESUMEN

Wool fiber diameter (WFD) is an important index of wool traits and the main determinant of wool quality and value. However, the genetic determinants of fiber diameter have not yet been fully elucidated. Here, coarse and fine wool of Wan strain Angora rabbits and their hair follicle traits were characterized. The results indicated significant differences in the diameters of wool fibers and their hair follicles. The RNA sequencing (RNA-Seq) technique was used to identify differences in gene expression in hair follicles between coarse and fine wool. In total, 2574 differentially expressed genes (DEGs) were found between the two hair follicle groups. Transcription factors, keratin-associated protein (KAP) and keratin (KRT) families, and ECM-related genes may control the structure of fine fibers in rabbits. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that skin development, epidermal cell and keratinocyte differentiation, epithelium development, and Notch and ribosome signaling pathways were significantly enriched, respectively. GSEA further filtered six important pathways and related core genes. PPI analysis also mined functional DEGs associated with hair structure, including LEF1, FZD3, SMAD3, ITGB6, and BMP4. Our findings provide valuable information for researching the molecular mechanisms regulating wool fiber and could facilitate enhanced selection of super-fine wool rabbits through gene-assisted selection in the future.

RESUMEN

The demand for durable, resistant, and high-strength structural material has led to the use of fibers as reinforcing elements. This paper presents an investigation into the inclusion of chopped steel wool fibers (CSWFs) in cement to form a high-flexural strength cementitious composite matrix (CCM). CSWFs were used as the primary reinforcement in CCM at increments of 0.5 wt%, from 0.5-6 wt%, with ratios of cement to sand of 1:1.5 and water to cement of 0.45. The inclusion of CSWFs resulted in an excellent optimization of the physicomechanical properties of the CCM, such as its density (2.302 g/cm3), compressive strength (61.452 MPa), and maximum flexural strength (10.64 MPa), all of which exceeded the performances of other reinforcement elements reported in the literature.

RESUMEN

Poly(lactic acid) (PLA) was plasticized with maleinized linseed oil (MLO) and further reinforced with sheep wool fibers recovered from the dairy industry. The wool fibers were firstly functionalized with 1 and 2.5 phr of tris(2-methoxyethoxy)(vinyl) (TVS) silane coupling agent and were further used in 1, 5, and 10 phr to reinforce the PLA/MLO matrix. Then, the composite materials were processed by extrusion, followed by injection-molding processes. The mechanical, thermal, microstructural, and surface properties were assessed. While the addition of untreated wool fibers to the plasticized PLA/MLO matrix caused a general decrease in the mechanical properties, the TVS treatment was able to slightly compensate for such mechanical losses. Additionally, a shift in cold crystallization and a decrease in the degree of crystallization were observed due to the fiber silane modification. The microstructural analysis confirmed enhanced interaction between silane-modified fibers and the polymeric matrix. The inclusion of the fiber into the PLA/MLO matrix made the obtained material more hydrophobic, while the yellowish color of the material increased with the fiber content.

RESUMEN

Computer color-matching (CCM) and the levelness of poly(ethylene glycol)-based reverse-micellar dyed wool fabrics in octane and nonane were investigated and compared with a conventional water-based dyeing system. Reflectance curves and calibration curves exhibited no chromatic change and maintained high linearity in both dyeing systems. The linearity of water-dyed calibration curves was slightly higher than that of the reverse-micellar dyed curves. The color yield, in term of K/Ssum values, of solvent-dyed samples was found to be generally higher than that of water-based dyed samples at various calibrated dye concentrations. The concentrations predicted by CCM were close to the theoretical concentrations for both dyeing methods. This indicates that octane- and nonane-assisted reverse-micellar dyeing of wool is able to generate color recipes comparable to the conventional water-based dyeing system. The solvent-dyed samples, measured by the relative unlevelness indices (RUI), exhibit good-to-excellent levelness, which is highly comparable with the water-dyed samples.

RESUMEN

Wool fiber is a natural protein fiber, which is used for the manufacturing of apparels, and floorcoverings because of its excellent fire retardancy, stain-resistance, antistatic and odor control properties along with exceptional warmth and resilience. However, wool fiber has several serious demerits, such as garments made of wool fibers extensively shrink during their laundering. To overcome this problem, wool fibers, especially those are used in apparel, are frequently shrink-resist treated to make them machine-washable. A wide range of treatments including oxidative, enzymatic, radiation, polymeric coatings, sol-gel coatings, and plasma treatments have been investigated to make wool fiber shrink-resistant. In this review, the mechanisms of wool fiber shrinkage, the research carried out until recently to make wool fiber shrink-resistant, and the current status of the sustainable alternatives developed, have been compiled and presented. The various methods investigated have been critically discussed with their merits and demerits, shrink-resist performance, and their shrink-resistance mechanisms. The chemistry and synthesis of various polymers used for the shrink-resistance and their reactions with wool fiber have been outlined. This review also includes the current challenges to make shrink-resist treatments green and sustainable, and also the future directions to meet these challenges. Some of the treatments investigated may affect the biodegradability of wool fibers, especially those are based on coating with synthetic polymers. A sustainable alternative polymeric coating based on sustainably produced polymeric resins, especially bio-based resins, needs to be developed so that the future treatments become sustainable.

RESUMEN

The keratin macromolecule in wool fiber may be found in α-helix or ß-sheet conformations besides a disordered portion. The physical and chemical treatments may cause transformations between α-helix and ß-sheet conformations. The aim of this study was to investigate the influence of lecithin treatment on the wool fiber using the micro-Raman spectroscopy and Fourier transform infrared spectroscopy. Characteristic bands found in the FTIR spectra of wool fibers including the amide A, amide B and amide I-III, which are assigned to the peptide bonds of wool keratin and arise from the amide bonds that link the amino acids. The lecithin treatment didn't affect the peak position of amide bands and only slightly influenced their intensity. It means that the lecithin treatment didn't change the chemical structure of wool fibers. The amide I and III regions, CC skeletal vibration region, and SS bonds vibration regions were analyzed with the Raman microscope. The results indicated the peak area of α-conformation increased gradually by lecithin treatment of the wool fiber, while the peak area of ß-conformation decreased. Therefore, it seems that lecithin treatment of the wool fiber resulted in transformation of ß-sheet to α-helix.

Asunto(s)

RESUMEN

Novel naphthalimide-poly(amidoamine) dendrimer fluorescent dyes were synthesized, and their structures were identified and confirmed using different characterization methods such as Fourier transform infrared, (1) H NMR, (13) C NMR, differential scanning calorimetry, elemental analysis and UV-vis spectroscopy. The spectrophotometric studies demonstrated absorption maxima (λmax ) and extinction coefficient (εmax ) values in the ranges of 429-438 nm and 25,635-88,618 L/mol/cm, respectively. The dyeing, fastness and antimicrobial properties of dyed wool fibers were examined. Colorimetric measurements demonstrated a greenish-yellow hue with remarkable fluorescence intensity on dyed wool. Although the fastness properties of naphthalimide dye on wool fibers were poor/moderate, color fastness was appreciably improved through modification of the dye using dendrimers. The results revealed that the newly synthesized dyes are potent antimicrobial agents on wool fibers. Overall, it was deduced that poly(amidoamine) (PAMAM) dendrimers could be exploited as a promising tool in tailoring the different properties of naphthalimide dyes, being suitable for dyeing and antimicrobial finishing agents for wool fibers. Copyright © 2015 John Wiley & Sons, Ltd.

Asunto(s)