Liquefied MDI products.Two isocyanates have been developed to help processors of polyurethanes solve the problem of liquefied diphenylmethane diisocyanate (MDI (1) (Multiple Document Interface) A Windows function that allows an application to display and lets the user work with more than one document at the same time. ) freezing during cold weather. Mondur MA-2300 isocyanate i·so·cy·a·nate n. Any of a family of nitrogenous chemicals that are used in industry and can cause respiratory disorders, especially asthma, if inhaled. and Mondur PF-LT isocyanate are liquid MDI adducts that are said to offer processors significantly improved freeze stability, but with processing and physical properties equal or superior to the company's Mondur PF modified monomeric monomeric /mono·mer·ic/ (mon?o-mer´ik) 1. pertaining to, composed of, or affecting a single segment. 2. in genetics, determined by a gene or genes at a single locus. MDI product. These two products feature the same isocyanate content, 23%, as the Mondur PF product. However, a new monomeric MDI modification process patented by the company makes the two new isocyanates freeze-stable at temperatures significantly lower than the 59 [degrees] F (15 [degrees] C) freezing point freezing point Temperature at which a liquid becomes a solid. When the pressure surrounding the liquid is increased, the freezing point is raised. The addition of some solids can lower the freezing point of a liquid, a principle used when salt is applied to melt ice on of Mondur PF. Mondur PF-LT isocyanate has a freezing point of 41 [degrees] F (5 [degrees] C). Mondur MA-2300 isocyanate has even greater freeze stability, offering a freezing point of 32 [degrees] F (0 [degrees] C). In trials conducted with typical one-shot polyurethane formulations, Mondur PF and Mondur PF-LT isocyanates produced nearly identical reaction profiles, pot life and exotherm. Mondur MA-2300 isocyanate exhibited a longer pot life and lower exotherm than the Mondur PF and Mondur PF-LT products. If desired, reaction rates of Mondur MA-2300 isocyanate can be accelerated by catalysis catalysis Modification (usually acceleration) of a chemical reaction rate by addition of a catalyst, which combines with the reactants but is ultimately regenerated so that its amount remains unchanged and the chemical equilibrium of the conditions of the reaction is not . (Bayer) Circle 112 on card |
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