Abstract: There is disclosed a process for the regulation of the molecular weight of high cis polybutadiene prepared by polymerizing butadiene under solution polymerization conditions employing as the catalyst system a mixture of (a) organoaluminum compounds; (b) organonickel compounds; and (c) fluorine containing compounds; said polymerization being conducted in the presence of alkali or alkaline earth metal salts of organic carboxylic acids.

Abstract: Triorgano substituted-tin lithium initiators are made in a dimethyl ether solvent. The substitution of dimethyl ether as the solvent for the traditional tetrahydrofuran solvent results in an initiator for anionic polymerizations that can produce less 1,2-vinyl repeat units. The dimethyl ether is also easier to remove from the polymerization media because it has a boiling point at one atmosphere of minus 24.8.degree. C. and thus is a gas at 25.degree. C.

Abstract: An anionic polymerization initiator comprising the reaction product of a an organatin halide and lithium in a suitable solvent. Elastomeric polymers prepared with these initiators have tin containing functional groups on substantially every polymer chain and provide vulcanizable rubber compounds exhibiting reduced hysteresis. Articles such as tires, produced with low hysteresis elastomeric polymers have lower rolling resistance. Methods are also provided for preparing the initiators and the elastomers having reduced hysteresis properties.

Abstract: Increased reactivity of isocyanate terminated polyether prepolymers with metal halide salt complexes of methylenedianiline is obtained when the polyether intermediates are modified to contain an effective amount of ethylene oxide. A desired intermediate is poly(oxypropylene) diol or triol which are modified to contain ethylene oxide units therein and subsequently reacted with a polyisocyanate such as MDI, that is 4,4'-diphenylmethane diisocyanate, or TDI, that is, toluene diisocyanate. A desired metal halide salt complex of methylenedianiline is the sodium chloride salt complex (MDA.sub.3 -NaCl), dispersed in dioctylphthalate (50/50 wt/wt).

Abstract: Our invention is directed to a process for producing processable thermoplastic elastomer blends of nitrile rubber with a crystalline polyamide mixture of at least two polyamides at a temperature below the melting temperature of the highest melting polyamide, but above the melting point of the lowest melting polyamide. The amount of nitrile rubber ranges from about 20 to about 80 percent by weight with the polyamides ranging from about 80 to about 20 percent by weight. Although processed at a temperature below the melting point of the highest melting polyamide, usually present in a substantial amount, the compounds surprisingly were readily mixed with the blends being smooth with no loose or fibrous material therein.

Abstract: A method for increasing the primary hydroxyl end groups in polyethers includes the steps of charging a reaction vessel with tetrahydrofuran and propylene oxide, adding BF.sub.3 or a BF.sub.3 -containing catalyst and then polymerizing the first pair of monomers to form a copolymer. After the first copolymerization is at least 60 percent complete, the method further includes the steps of adding ethylene oxide to the copolymer and unreacted monomers in the reaction vessel, and polymerizing the contents therein to form a terpolymer predominantly terminated by primary hydroxyl groups. The reaction is thereafter terminated and the terpolymer is separated from the remaining contents of the reaction vessel, washed and dried. The resulting terpolymer has from about 20 to about 80 weight percent of tetrahydrofuran, from about 10 to about 60 weight percent of propylene oxide, from about five to about 40 weight percent of ethylene oxide and at least 60 mole percent of terminal primary hydroxyl groups.