RESUMO
The number of chronic kidney disease (CKD) persons continues to rise in Mexico. They require renal replacement therapy, and in the absence of it, hemodialysis is the major option for their survival. The uremic toxins present in the blood are removed by hemodialysis, which involve membranes. In this study, nonwoven fabrics with modified carbon black nanoparticles in a matrix polymer of Nylon 6 were obtained and evaluated as an adsorbent material of uremic toxins. All nonwoven fabrics were characterized by FTIR, XRD, TGA, SEM, and contact angle measurements and were evaluated as an adsorbent material for the urea toxin and as an albumin retainer. The findings suggest their potential application as a hemodialysis membrane. Nanocomposites had a higher hydrophilic characteristic compared to pure Nylon 6. The average diameter size of the fibers was in the range of 5 to 50 µm. All nanocomposites nonwoven fabrics showed high removal percentages of inulin in a range of 80-85% at 15 min of contact. Most Ny6 Zytel/CB nanocomposites showed a high percentage of urea removal (80 to 90%).
RESUMO
Nowadays, highly flammable and harmful plastic materials are used in many daily applications. To prevent burning of materials, other harmful molecules or materials that are not environmentally friendly are added to plastics. To overcome this environmental issue, new materials have been investigated. Lignin, an industrial by-product, is an abundant biopolymer that can be used in fire safety plastics; it is considered a renewable and readily available resource. In this work, PP-TiO2/lignin composites were obtained with TiO2/lignin mixtures through the melt extrusion process, with different weight percentages of nanoparticles (10, 20, 25, and 30 wt.%). The PP-TiO2/lignin composites were characterized by XRD, FTIR, TGA, and SEM. Furthermore, cone calorimetry tests and the mechanical properties were evaluated. Cone calorimetry tests revealed that the introduction of 25 wt.% TiO2-lignin to the PP matrix reduced the peak of heat release rate (PHRR) and total heat release (THR) by 34.37% and 35.45%, respectively. The flame retardancy index (FRI) values of the composites were greater than 1.0 and were classified as good; the highest value of 1.93 was obtained in the PP-30 sample. The tensile tests demonstrated that the flexural modulus of the composites increased gradually with increasing lignin and TiO2 content, and the flexural strength decreased slightly. The use of lignin in PP composites can be an excellent alternative to synthesize new materials with improved flame-retardant properties and which is friendly to the environment.
RESUMO
High uric acid levels cause different clinic conditions. One of them is hyperuricemia, which leads to kidney damage. A solution for eliminating uric acid in the blood is by hemodialysis, which is performed using nanocomposite membranes. In this work, Nylon 6 nanocomposites were synthesized with modified carbon black (MCB), which were considered candidate materials for hemodialysis membranes. The modification of carbon black was made with citric acid using the variable-frequency ultrasound method. The new MCB was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and dispersion tests. Nylon 6/MCB nanocomposites were processed using the ultrasound-assisted melt-extrusion method to improve the dispersion procedure of the nanoparticles. The Nylon 6/MCB nanocomposites were characterized by FTIR, TGA, and differential scanning calorimetry (DSC). These were assessed for the absorption of toxins and hemocompatibility. MBC and nanocomposites showed excellent uric acid removal (78-82%) and hemocompatibility (1.6-1.8%). These results suggest that Nylon 6/MCB nanocomposites with low loading percentages can be used on a large scale without compatibility problems with blood.
