Disclosed is a moisture reactive polyurethane hot melt adhesive composition that can be applied to substrates at a low coating weight even at application temperatures as low as 60 to 95° C. while retaining the advantageous high tack, green strength, cured bond strength and toughness of conventional high melting point polyurethane hot melt adhesives.

Described herein is a process for producing polyurethane foams having a density of 30 g/dm.sup.3 to 70 g/dm.sup.3, in which (a) aromatic polyisocyanate is mixed with (b) polymeric compounds having isocyanate-reactive groups, (c) optionally chain extender and/or crosslinking agent, (d) catalyst, (e) blowing agent including water, (f) 0.1% to 5% by weight of lactam, and (g) optionally additives, at an isocyanate index of 50 to 95 to form a reaction mixture, and the reaction mixture is converted to the polyurethane foam, wherein the catalyst includes metal catalyst and amine catalyst, and the amine catalyst has tertiary nitrogen atoms and the content of tertiary nitrogen atoms in the amine catalyst is from 0.0001 to 0.003 mol/100 g of foam. Also described herein is a polyurethane foam and a method of using such a flexible polyurethane foam for the production of cushions, seat cushions, or mattresses.

Disclosed herein is a polyurethane foam sponge produced by the steps of a) providing an hydrophobic polyol which has six hydroxyl groups, b) providing a hydrophilic diisocyanate obtained by reacting a diisocyanate with a hydrophilic polyether diol, c) reacting the hydrophobic polyol with the hydrophilic diisocyanate to obtain a prepolymer which includes 3 to 6 isocyanate groups, and d) mixing the prepolymer with a hydrophilic polyether polyol, a blowing agent, an end-capping agent, a reinforcing agent, and a catalyst to obtain the polyurethane foam sponge. A wound dressing including the polyurethane foam sponge is also disclosed.

Disclosed herein is a polyurethane foam sponge produced by the steps of a) providing an hydrophobic polyol which has six hydroxyl groups, b) providing a hydrophilic diisocyanate obtained by reacting a diisocyanate with a hydrophilic polyether diol, c) reacting the hydrophobic polyol with the hydrophilic diisocyanate to obtain a prepolymer which includes 3 to 6 isocyanate groups, and d) mixing the prepolymer with a hydrophilic polyether polyol, a blowing agent, an end-capping agent, a reinforcing agent, and a catalyst to obtain the polyurethane foam sponge. A wound dressing including the polyurethane foam sponge is also disclosed.

A plasticization-resistant polyurethane membrane for gas separation and producing method are disclosed. The plasticization-resistant polyurethane membrane may include a soft segment, a hard segment and a chain extender. The soft segment may include a polyol compound and the hard segment may include a diisocyanate. The plasticization-resistant polyurethane membrane may be a cross-linked polyurethane membrane.

The present disclosure provides a liquid-state reactive polyurethane adhesive, which includes a polyurethane prepolymer. The polyurethane prepolymer is blocked by an isocyanate group, and the polyurethane prepolymer is obtained by a polymerization reaction, a reactive monomer of the polymerization reaction includes a polyisocyanate, a polyol, a stabilizer, a catalyst and a hydrophobic filler. A functionality of the polyisocyanate is 2.4 to 3. A molecular weight of the polyol is 1000 to 8000, and the polyol has hydrolysis resistance. The stabilizer has a structure represented by formula (I). The catalyst has a structure represented by formula (II). Formula (I) and formula (II) are as defined in the specification.

A thermoplastic polyamide can be obtained through the reaction of at least the components (i), (ii), and (iii), where a catalyst having a Lewis base component is used in the reaction. Component (i) is a composition containing a polymeric compound having two carboxylic acid moieties; component (ii) is a dicarboxylic acid composition containing at least one dicarboxylic acid; and component (iii) is a diisocyanate composition containing at least one diisocyanate. A process can be used for producing the thermoplastic polyamide and a method for the use thereof. A tandem reactive extruder can be used for the reaction.

The presently claimed invention provides a continuous process for preparing a polyurethane composition which behaves as a rheology modifier upon addition to paint and coating formulations. The present process employs mixers for homogenization of highly viscous polyurethane polymers and by adjusting the process parameters and reactor conditions in specified ranges obtained a polyurethane composition. The polyurethane composition obtained from the process of the present invention is used as thickener in water-borne paint and coating formulations.

A polyol component P) contains at least two different polyether polyols A) and C), and at least one polyether ester polyol D). A process can be used for producing rigid polyurethane foams using the polyol component P), and the rigid polyurethane foams produced therefrom are useful.

The present invention relates to a method for preparing a polyurethane foam, in particular an aerogel, from at least one polyisocyanate and at least one optionally recycled polyol, and to the use thereof.