نتایج جستجو برای: 4 diisocyanate
تعداد نتایج: 1304649 فیلتر نتایج به سال:
Background: In the foam industries, workers are exposed to various chemicals and working with these chemicals without considering occupational safety and health considerations could lead to different harmful symptoms. Consequently, in order to control measures and reducing risk to acceptable level, it is necessary to assess the health risk of exposure to harmful chemicals by implementation of s...
Polyurethanes and polyurethane-ureas were prepared by the reaction of diethylene glycol and polyethylene glycol with excess of aromatic and aliphatic diisocyanate to yield isocyanate terminated prepolymers which were subsequently reacted with diols and diamines. These polymers were characterized by IR, 1HNMR spectra, viscosity measurements and thermogravimetric analysis.
A series of polyurethane elastomers based on an aliphatic diisocyanate and a polyether macroglycol was polymerized with various cross-link densities and OH/NCO ratios. Stoichiometries yielding between 8,600 and 12,900 gm/mole/crosslink and an OH/NCO ratio of 1.1 resulted in polymers with the low modulus, yet high strength and elongation necessary for maxillofacial applications.
In this work, 5,6,7,8-Tetrabromo-2,3-dihydro-2,3-bis(2-hydroxyethyl)phthalazine-1,4-dione is synthesized by the reaction of 5,6,7,8-tetrabromo-2,3-dihydrophthalazine-1,4-dione with 2-bromoethanol in the presence of triethylamine. The obtained monomer was polymerized with different diisocyanates, including hexamethylenediisocyanate (HMDI), tolylene-2,4-diisocyanate (TDI), isophoronediisocyanate ...
OBJECTIVES The pathogenic basis of respiratory disorders associated with isocyanates are still obscure. One reason for this is the lack of good estimates of human exposure. In this study exposure was estimated by measurement of isocyanate metabolites in biological samples. METHODS In a factory using isocyanate based polyurethane (PUR) glue, isocyanate concentrations in air were measured by li...
THREE DIISOCYANATES CAN CAUSE OCCUPATIONAL ASTHMA (OA): toluene diisocyanate (TDI), 4,4 diphenylmethane diisocyanate (MDI), and 1,6-hexamethylene diisocyanate (HDI). We analyzed potential biomarkers of isocyanate-induced OA, based on investigated immunologic, genetic, neurogenic, and protein markers, because there is no serological testing method. The prevalence of serum IgG to cytokeratin (CK)...
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