Abstract: A polyol composition having a number average molecular weight of from about 1,000 to about 3,000 Daltons is made up of (1) at least 60% by weight of a low monol polyoxypropylene polyol having a number average molecular weight of from about 2,000 to 12,000 Da and a degree of unsaturation less than or equal to 0.02 meq/g and (2) no more than 40% by weight of a polyol having a number average molecular weight of from about 400 to about 1,000 Da and a polydispersity index greater than 1.1. This polyol composition is reacted with a diisocyanate, a polyisocyanate, an isocyanate-terminated prepolymer or an isocyanate-terminated quasi-prepolymer to produce polyurethane elastomers having good physical and mechanical properties. Any of the known processes for producing polyurethane elastomers, including one-shot processes, may be used to produce elastomers in accordance with the present invention.

Abstract: A polyurethane-forming reaction mixture characterized by its ability to be adjusted with respect to its viscosity in response to changing temperature and humidity conditions is achieved with a mixture that includes a liquid polyisocyanate having an isocyanate group content of at least 10% by weight, an isocyanate-reactive component which includes at least one high molecular weight polyol, a urethane catalyst and from 0.2 to 5 parts by weight per 100 parts by weight of isocyanate reactive component of a viscosity adjusting component. The viscosity adjusting component is preferably a diamine, a polyamine and/or an amine-terminated polyol. This reaction mixture is particularly useful for producing polyurethane geotextile composite materials useful as liners for ditches and canals.

Abstract: Preparation of moisture-curable, alkoxysilane-functional polyether urethanes by reacting at an NCO:OH equivalent ratio of 1.5:1 to 2.5:1 a) a hydroxyl component containing i) 20 to 100 wt. %, of a polyether diol and other polyether segments, where the polyether segments have Mn of at least 3000 and degree of unsaturation of less than 0.04 meq/g, where the sum of Mn of polyether segments per molecule averages 6000 to 20,000, and ii) 0 to 80 wt. % of a polyether monool and other polyether segments having Mn of 1000 to 15,000, with b) an isocyanate component containing i) 20 to 100 wt. % of a diisocyanate, and ii) 0 to 80 wt. % of a monoisocyanate, forming an isocyanate-containing reaction product reacted at an equivalent ratio of 0.8:1 to 1.

Abstract: The present invention provides NCO prepolymers comprising the reaction product of (1) an allophanate-modified diphenylmethane diisocyanate having an NCO group content of 12 to 32.5% by weight and comprising the reaction product of, (a) an aliphatic alcohol or an aromatic alcohol; and (b) diphenylmethane diisocyanate comprising: (i) from 10 to 60% by weight of 2,4′-diphenylmethane diisocyanate, (ii) less than 6% by weight of 2,2′-diphenylmethane diisocyanate, and (iii) the balance being 4,4′-diphenylmethane diisocyanate, wherein the sum of the percentages by weight of (1)(b)(i), (1)(b)(ii), and (1)(b)(iii) total 100% by weight of (1)(b), and (2) a polyether polyol having a molecular weight of 134 to 10,000, an OH number of 420 to 14, and a functionality of at least 1.8. The NCO prepolymers of the present invention find use in preparing elastomeric coatings, adhesives, sealants, and the like.

Abstract: Seams are sealed and surface defects are repaired in a polyurethane/geotextile composite applied over concrete, an earthen canal or a ditch with a non-sagging polyurethane composition. This non-sagging polyurethane composition is a reaction product of a polyisocyanate, a high molecular weight polyhydroxyl compound, and a compound containing at least two amino groups. A low molecular weight diol or triol, a catalyst and a filler are optionally included in the polyurethane-forming reaction mixture.