摘要:
A reaction product containing urethane groups, comprising one or more species of the general formula (I) (R1—X)p—Z1—(XH)y (I) where p+y=w and w is an integer from 2 to 10, p is an integer from 2 to 10, y is an integer from 0 to 8, and X is independently O, NH and/or NZ2 and XH is independently a hydroxyl group OH, a primary amino group NH2 and/or a secondary amino group NHZ2 where Z2 is independently a branched or unbranched, saturated or unsaturated organic radical G(U)a where U is independently a hydroxyl group, a primary amino group or a secondary amino group and a is an integer from 0 to 8, where w+a≤10, G is a branched or unbranched, saturated or unsaturated organic radical, the p R1 radicals are independently a radical of the general formula (II) Y—O—CO—NH—R2—NH—CO (II) in which the p Y radicals are independently a branched or unbranched, saturated or unsaturated organic radical which has 1 to 1000 carbon atoms and does not contain any hydroxyl groups, any primary amino groups or any secondary amino groups, the p R2 radicals are independently a branched or unbranched, saturated or unsaturated organic radical having 6 to 20 carbon atoms, and Z1 is a branched or unbranched, saturated or unsaturated organic radical which contains at least one tertiary nitrogen group and is free of XH groups.
摘要:
The present invention relates to a two-part composition suitable for use in the preparation of a foamed material wherein the first part comprises a source of metal ions and water and the second part comprises an isocyanate, wherein the ratio of NCO isocyanate to water to metal ions is 1 mol:3.5 to 5.5 mol:95 to 650 mmol. Also forming part of the invention is a foamed isocyanate material, a method of preparing the material and controlling foam formation and uses of the composition and material.
摘要:
The disclosure provides reversible polymers from polyurea by modifying the nitrogen atom with hindered substituents. The reversibility of hindered urea bond (HUB) can be controlled by changing the bulkiness of the substituents, and N-tert-butyl-N-ethylurea (TBEU), with its high binding constant and short lifetime, is applicable in the design of reversible polymer and self-healing materials at mild temperatures without external stimuli. HUB can be used in the design of smart materials with its adjustable reversibility, facile synthesis, and compatibility with many other polymer structures.
摘要:
A multilayer chemical mechanical polishing pad stack is provided containing: a polishing layer; a rigid layer; and, a hot melt adhesive bonding the polishing layer to the rigid layer; wherein the polishing layer exhibits a density of greater than 0.6 g/cm3; a Shore D hardness of 5 to 40; an elongation to break of 100 to 450%; and, a cut rate of 25 to 150 μm/hr; and, wherein the polishing layer has a polishing surface adapted for polishing the substrate.
摘要:
A nutrient or medicinal composition for administration to ruminants, which includes a core of one or more biologically active substances coated with a film of polyurethane, overcoated with an “intermediate” wax is disclosed. This polyurethane/wax coating is resistant to rumen conditions, but will release the biologically active substance(s) in the abomasum and subsequent digestive tract of the ruminant animal.
摘要:
Polyurethane elastomers having solids contents greater than 40% by weight are produced from a sprayable polyurethane-forming system composed of an isocyanate component and an isocyanate-reactive component. The isocyanate component has a solids content of from 40 to 80 wt. %, based on total weight of isocyanate component and is made up of at least one aromatic polyisocyanate having an NCO content of from 24 to 33%, a functionality of from 2 to 3 and at least one solid filler. The isocyanate-reactive component has a solids content of from 40 to 80 wt. %, based on total weight of the isocyanate-reactive component and is composed of at least one polyether polyol having a hydroxyl number of from 25 to 40 and a functionality of from 2 to 4, and at least one solid filler.
摘要:
A method of forming ionically-charged, colorant nanoparticles involves forming in-situ ionically-charged polyurethane monomers, and forming an emulsion including the ionically-charged polyurethane monomers and a colorant nanoparticle. The method further involves polymerizing or crosslinking the ionically-charged polyurethane monomers in the emulsion, where the polymerizing or crosslinking chemically attaches the ionically-charged polyurethane monomers to a surface of the colorant nanoparticle to form an ionically-charged encapsulation layer on the surface.
摘要:
Polyurethane coating compositions that provide transparent, abrasion-resistant, and water-washable anti-fog coatings when applied to a substrate and cured are described herein. These polyurethane coating compositions have surfactants that are chemically associated with the polyurethane so as to not leach out or wash away when the coating surface is soaked or washed with water. The polyurethane coating compositions comprise isocyanate-reactive surfactants, isocyanate-reactive salts of surfactants, carboxylic-reactive surfactants, or combinations thereof that are chemically bonded to the polyurethane. Articles coated with such polyurethane coating compositions, and processes for applying the coating compositions to a substrate, are also provided herein.
摘要:
Polyurethane elastomers are formed by curing a reaction mixture containing at least one polyisocyanate at least one polyol, an aliphatic diol chain extender and a small amount of a secondary amino compound that may have none or one or more hydroxyl groups. The reaction is catalyzed with a metal catalyst. In certain embodiments, the catalyst is an organozirconium, organotitanium or tertiary amine-based catalyst. The presence of the secondary amine compound in those cases provides for a good surface appearance and good physical properties.
摘要:
Biocompatible macromer compositions are provided including an isocyanate-functional polyalkylene oxide combined with at least one multi-functional isocyanate as a first component, and a multi-amino functional compound possessing multiple primary amines as a second component. The isocyanate-functional polyalkylene oxide has pendant polyalkylene oxide groups. The resulting biocompatible macromer composition can be employed as an adhesive or sealant for medical/surgical uses.