POLYURETHANE AND PROCESS FOR MAKING This invention relates to polyurethanes and methods for manufacturing them. Elastomeric polyurethanes are used widely in a large array of coating, adhesive, sealant and elastomer (“CASE”) applications. The polyurethane is in many cases a reaction product of an organic polyisocyanate, a hydroxyl-terminated chain extender and a polyether polyol that has a hydroxyl equivalent weight of greater than 260. The polyether polyol often has secondary hydroxyl groups that react slowly towards isocyanate groups. For this reason, the reaction is usually catalyzed. The most prevalent urethane catalysts are metal catalysts such as tin, mercury and zinc catalysts, and low molecular weight amine catalysts such as certain tertiary amines and diaza compounds. In general, these catalysts have been found to be necessary to provide curing rates that are economically feasible. There are important reasons why it would be beneficial to eliminate the catalysts in some cases. Costs would be reduced if catalysts were not needed. Many metal catalysts have been associated with environmental and/or health and safety concerns. Several problems are associated with amine catalysts. They often are hygroscopic and sometimes are moisture-sensitive. Non-reactive, low molecular weight amine catalysts are often somewhat volatile and can contribute to odor and the presence of volatile organic compounds (VOCs) in the product. In addition, the presence of an amine catalyst often reduces the shelf life of the precursors, isocyanate-terminated prepolymers in particular. In addition, catalyst residues in the polyurethane can catalyze depolymerization reactions, particularly at higher temperatures. These higher temperatures are sometimes encountered during the normal use of the cured product. Sometimes the polyurethane is used in a high temperature environment or becomes exposed to transient temperature excursions. In other cases the polyurethane is used in a dynamic application in which external and internal friction can heat the polymer to high temperatures. Exposure to high temperature can result in depolymerization that reduces performance or leads to material failure.