Provided are a method of preparing a polyurethane prepolymer with high functionality and the polyurethane prepolymer with high functionality prepared therefrom and a curing agent comprising the same. The method includes the steps of: Step (A): providing an alcohol composition comprising a first polyol having 2 or 3 OH groups and a second polyol having 4 or more OH groups; Step (B): reacting the alcohol composition with a polyisocyanate to undergo a first polymerization, so as to obtain an intermediate; wherein a molar ratio of a total number of the OH groups of the alcohol composition to a total number of NCO groups of the polyisocyanate is from 1:2 to 1:6; and Step (C): adding a catalyst to carry out a second polymerization of the intermediate to obtain the polyurethane prepolymer with high functionality, which has four or more NCO groups.

The invention relates to an aromatic allophanate polyisocyanate based on aromatic diisocyanates, containing a) 15 mol-% of allophanate groups, based on the sum of urethane, allophanate and isocyanurate groups, b) 50 mol-% of isocyanurate groups, based on the sum of urethane, allophanate and isocyanurate groups and c) 1.5% by weight of monomeric diisocyanates, based on the total weight of the aromatic allophanate polyisocyanate. Furthermore, the invention relates to a process for producing aromatic allophanate polyisocyanates and their use in polyisocyanate compositions or two-component systems.

A polyisocyanate component, a polyurethane foaming system, and an article made therefrom, wherein the polyisocyanate component includes (a) a preformed mixture including an aromatic oxazolidone compound that is the reaction product of at least one aromatic epoxide and at least one first polyisocyanate having an average isocyanate functionality of no more than 2.7 and greater than 1.8, in the presence of at least one catalyst, the aromatic oxazolidone compound includes at least one free isocyanate group and at least one aromatic oxazolidone group, the aromatic oxazolidone group includes an aromatic group and an oxazolidone group, and (b) at least one second polyisocyanate has an average isocyanate functionality equal to or greater than 2.7 and less than 6.0. The second polyisocyanate is added to the preformed mixture to form the polyisocyanate component. The polyisocyanate component has a viscosity of no more than 4.0 Pa-sat 25 C., an aromatic oxazolidone group content of 2 weight percent to 10 weight percent based on a total weight of the polyisocyanate component, and an average isocyanate functionality of from 1.8 to 6.0.

A polyisocyanate composition contains a modified product of xylylene diisocyanate and a modified product of pentamethylene diisocyanate, and/or a modified product of the xylylene diisocyanate and the pentamethylene diisocyanate. The ratio of the pentamethylene diisocyanate with respect to the total amount of the xylylene diisocyanate and the pentamethylene diisocyanate is 30 mol % or more and 80 mol % or less.

An adhesive composition is made from a first part containing an isocyanate group-containing prepolymer that is a reaction product of a first isocyanate and at least one polyol; and a second isocyanate that is essentially unreacted with the first isocyanate, the at least one polyol, and the isocyanate group containing prepolymer; and a second part containing at least two polyols; wherein the adhesive composition is essentially free of diluent oils and solvents. A polyurethane adhesive is made by mixing the first part and the second part in a 1:1 to 1.2:1 weight ratio of the first part to the second part to form a mixture, and curing the mixture. The polyurethane adhesive can be used in articles, including semipermeable membranes and reverse osmosis modules. When a solvent is filtered through the semipermeable membranes by reverse osmosis, the polyurethane adhesive prevents or reduces osmotic blistering.

A polyisocyanate composition includes an isocyanurate derivative of xylylene diisocyanate, and a biuret derivative of aliphatic polyisocyanate.

Polyurethane-polyisocyanurate compounds and processes for preparing polyurethane-polyisocyanurate compounds are disclosed herein. A process includes mixing component (a) polyisocyanate with component (b) a mixture obtainable by introducing an alkali metal or alkaline earth metal salt into a compound RNHCOR containing urethane groups, where R is not hydrogen and is not COR, component (c) compounds containing one or more epoxide groups, component (d) one or more compounds having at least two isocyanate-reactive groups, comprising compounds having NH2 and/or primary OH groups, and component (e) optionally fillers and other additives, to form a reaction mixture, and reacting the reaction mixture to form the polyurethane-polyisocyanurate compound, wherein the molar amount of alkali metal and/or alkaline earth metal ions in the reaction mixture per mole of urethane group in component (b) is 0.0001 to 3.5 and the isocyanate index is greater than 150. Use of polyurethane-polyisocyanate compounds for producing vehicle parts is also disclosed.

A vegetable oil-based cartilage bionic cushioning and shock-absorbing material, and a preparation method and use thereof, is provided. The vegetable oil-based cartilage bionic cushioning and shock-absorbing material is prepared from a premix A and an isocyanate mixture B; the premix A including a vegetable oil-based modified polyol, a type 1 polyether polyol, a type 2 polyether polyol, a polymer polyol, a surfactant, a foaming agent, a chain extender, a catalyst and a cell regulator; the type 1 polyether polyol is a polyether polyol with a molecular weight of 400-1000 and a hydroxyl value of 110-280 mgKOH/g; and the type 2 polyether polyol is a polyether polyol with a molecular weight of 1000-10000 and a hydroxyl value of 25-56 mg KOH/g. The material provided by the present invention is environment-friendly and breathable with open cells, and has a high cushioning effect and a low permanent compression set value.

The invention relates to a polyisocyanate mixture comprising at least one polyisocyanurate which is based on tolylene diisocyanate and has isocyanate groups and at least one polyurethane which is based on tolylene diisocyanate and has isocyanate groups, wherein the polyisocyanate mixture has a) a solids content of from 51 to 90% by weight, based on the total weight of the polyisocyanate mixture and b) a content of monomeric tolylene diisocyanate of 0.9% by weight, based on the total weight of the polyisocyanate mixture, and the polyisocyanurate which is based on tolylene diisocyanate and has isocyanate groups has a polydispersity D of from 1 to 1.5, based on the total weight of the polyisocyanurate which is based on tolylene diisocyanate and has isocyanate groups, where the polydispersity D is the ratio of weight average and number average molecular weight of the polyisocyanurate and the weight average and number average molecular weight is in each case determined by means of gel permeation chromatography using a polystyrene standard and tetrahydrofuran as eluent in accordance with DIN 55672-1:2016-03.

A method for deblocking a blocked isocyanate is described herein. The method includes contacting a blocked isocyanate and a halide ion source under conditions effective to provide a deblocked isocyanate. A method of making a polyurethane is also disclosed. The method of making a polyurethane includes combining a blocked isocyanate, a polyol, and a halide ion source in the presence of solvent and under conditions effective to provide the polyurethane.