Abstract: This invention relates to a polyisocyanate prepolymer for polyurethane and polyurethane/urea elastomer synthesis and to the resulting elastomer. The prepolymer is formed by reacting a cyclohexanediisocyanate with a long chain polyol under conditions such that essentially a 2:1 adduct is formed. Excess cyclohexanediisocyanate is removed prior to forming the elastomer.

Abstract: This invention relates to improved polyurethane systems prepared by reacting an organic polyisocyanate with a hydroxyl containing compound, the improvement comprising utilizing mono tertiary-alkyltoluenediamine where the tertiary-alkyl group is ortho to an amine group as a chain extender or component thereof. The ortho-tertiary-butyltoluenediamine isomer is particular effective for use in reaction injection molding of polyurethanes and can be formulated with polyol as a chain extender mix.

Abstract: The present invention relates to polyurethanes and a method for making polyurethanes by reacting an organic diisocyanate, a glycol having a molecular weight of 500-5000 and a derivative of 2,6-diaminobenzoic acid or a blend comprising derivatives of 2,4-diaminobenzoic acid and 2,6-diaminobenzoic acid. The addition of the 2,6-diaminobenzoic acid derivative to the composition improves polyurethane processability and performance by decreasing chain extender reactivity and increasing hard segment regularity.

Abstract: This invention relates to a polyisocyanate prepolymer for polyurethane/urea elastomer synthesis and to the resulting elastomer. The prepolymer is formed by reacting toluenediisocyanate with a long chain polyol under conditions such that essentially a 2:1 adduct is formed. Excess toluenediisocyanate is removed prior to forming the elastomer.

Abstract: This invention relates to an improved hydrogenation process wherein methylenedianiline is reduced to form bis(para-aminocyclohexyl)methane (PACM). The process contemplates contacting methylenedianiline and hydrogen in the presence of a two component metal catalyst comprising rhodium and ruthenium under mild hydrogenation conditions. Use of the mixed metal catalyst system allows one to obtain a preselected isomer ratio having from about 5-40% by weight, typically 14-28% by weight of the trans,trans- configurational isomer.

Abstract: This invention relates to a class of tertiary-alkyltoluenediamines having alkyl groups ortho to an amine group. More particularly the aromatic diamines are represented by the formulas: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are C.sub.1-3 alkyl groups or R.sub.2 and R.sub.3 are combined to form a C.sub.5-6 membered ring.The above described alkylated aromatic diamines have been found to be well suited for use as a chain extender in forming polyurethane/urea elastomer systems and the mono tert-butyltoluenediamine isomers have been found to be nonmutagenic in the Ames test.

Abstract: This invention relates to a solvent-free process for producing polyurethane/urea elastomers wherein an aromatic diisocyanate is reacted with a compound having active Zerewitinoff hydrogen atoms and an aromatic diamine chain extender. The improvement for producing urethanes having a wide range of properties comprises including a urethane-linked diisocyanate in the polyurethane urea elastomer. The urethane-linked diisocyanate is one that is formed by reacting toluenediisocyanate or substituent thereof with a short chain diol under conditions such that the urethane linked diisocyanate comprises two equivalents isocyanate per equivalent diol.

Abstract: This invention relates to urethane linked mixtures of 2,4- and 2,6-toluenediisocyanates (ULTDI dimers) having low melting points and to a method of forming these systems. The urethane linked toluenediisocyanates containing from 45-90% of the 2,4- and 10-55% of the 2,6- isomer by weight are formed by reacting two moles of an appropriate isomer mix of toluenediisocyanate, with one mole of a specific alkylene glycol, e.g., 1,2-butanediol, diethylene glycol or dipropylene glycol under conditions such that essentially only one of the isocyanate groups on a toluenediisocyanate molecule reacts with a hydroxyl group of the glycol. Conditions are controlled such that the urethane linked toluenediisocyanates are formed. The resulting product, which has two unreacted isocyanate groups, is suited for producing a variety of elastomers including polyurethane polyurethane/urea or polyurea elastomers.

Abstract: A multistage treatment is disclosed for the removal of carbonaceous BOD and nitrogenous pollutants from wastewaters, wherein the influent wastewater undergoes successive nitrification-denitrification in the presence of recycled activated sludge containing a mixed culture biomass comprising heterotrophic and autotrophic organisms. The initial mixing of the wastewater with recycled sludge is effected in the presence of sufficient oxygen to maintain oxic conditions. The mixed liquor from the initial oxic treatment, without intermediate separation of solids, is passed to an anoxic stage wherein nitrites and nitrates (NO.sub.x .sup.-, x = 2,3) formed by oxidation of ammonium compounds are reduced to nitrogen gas. Any number of oxic treating stages each followed by an anoxic stage may be employed. The final treating stage prior to solids separation from the mixed liquor may be either oxic or anoxic. The separated solids constitute the activated sludge recycled to at least the initial mixing stage.