Components for manufacturing polyurethane foams can adversely affect the human body, particularly if they are in contact with it for long periods. In applications where the foam is not placed directly into the body, the study of the product's effects is often neglected. In the case of human skin, distinguishing the increasingly frequent problems of skin atopy, more attention should be paid to this. This paper presents the influence of the different catalytic systems on cytotoxic and thermomechanical properties in polyurethane foams. Among others, foams were produced with the most popular catalysts on the market, DABCO and a metal-organic tin catalyst. The foams were characterized by thermomechanical properties and were subjected to a cytotoxicity test against human keratinocytes. In biocompatibility tests with skin cells, the results were highly variable. VAB 2 with a catalytic system consisting of commercial Diethanolamine and Addocat105 performed the best. However, with such a catalytic system, the mechanical properties have worsened.
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http://dx.doi.org/10.3390/ma16041527 | DOI Listing |
ACS Omega
January 2025
School of Chemical Engineering, Vellore Institute of Technology, Vellore, Tamil Nadu 632014, India.
This work explores the enhancement of EMI shielding efficiency of polyurethane (PU) foam by loading multiwall carbon nanotube (MWCNTs)-decorated hollow glass microspheres (HGMs). MWCNT was coated onto the HGM surface by a simple solution casting technique. The coated HGM particles were loaded in PU foams, resulting in an even dispersion of MWCNT in the foam struts, thereby forming an interconnected conductive network in the polymer matrix.
View Article and Find Full Text PDFSoft Matter
January 2025
James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637, USA.
We measure the response of open-cell polyurethane foams filled with a dense suspension of fumed silica particles in polyethylene glycol at compression speeds spanning several orders of magnitude. The gradual compressive stress increase of the composite material indicates the existence of shear rate gradients in the interstitial suspension caused by wide distributions in pore sizes in the disordered foam network. The energy dissipated during compression scales with an effective internal shear rate, allowing for the collapse of three data sets for different pore-size foams.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Latvian State Institute of Wood Chemistry, Dzerbenes Street 27, LV-1006 Riga, Latvia.
The use of black alder (BA) bark biomass in rigid polyurethane (PUR) foam compositions was the main task of investigation. Extractive compounds isolated from the bark through hot water extraction were used as precursors for bio-polyol synthesis via acid-free liquefaction with the polyether polyol Lupranol 3300 and through oxypropylation with propylene carbonate. The OH functionality and composition of the polyols were analyzed via wet chemistry and FTIR spectroscopy.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
School of Energy and Building Environment, Guilin University of Aerospace Technology, Guilin 541004, China.
In this paper, we investigated the efficient metal-free phosphorus-nitrogen (PN) catalyst and used the PN catalyst to degrade waste PU with two-component binary mixed alcohols as the alcohol solvent. We examined the effects of reaction temperature, time, and other factors on the hydroxyl value and viscosity of the degradation products; focused on the changing rules of the hydroxyl value, viscosity, and molecular weight of polyols recovered from degradation products with different dosages of the metal-free PN catalyst; and determined the optimal experimental conditions of reaction temperature 180 °C, reaction time 3 h, and PN dosage 0.08%.
View Article and Find Full Text PDFMolecules
December 2024
Institute of Chemistry, University of Miskolc, 3515 Miskolc-Egyetemváros, Hungary.
In this work, α-tocopherol and trolox were studied as compounds that have high biological activity. α-Tocopherol is considered a food additive because the refining process of vegetable oils causes the depletion of this vitamin, and thus, its inclusion is required to keep them from oxidizing. Computational tools have determined the antioxidant activity of these additives.
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