Abstract: A process for producing EP and EPDM polymers with a reduction in fouling is provided, which process comprises polyemrizing ethylene, an alpha-olefin and a nonconjugated diolefin (if utilized) in a polymerization medium comprising a hydrocarbon diluent at a temperature of from about -50.degree. C. to about 150.degree. C. in the presence of a catalyst system comprising (a) a vanadium compound, (b) diethyl aluminum chloride, ethyl aluminum sesquichloride or ethyl aluminum dichloride and (c) an organo aluminum compound of the formula R.sub.3 Al wherein R is an alkyl group having from 8 to 12 carbon atoms and, optionally, triethyl aluminum, the molar ratio of chloride in diethyl aluminum chloride to the total aluminum content in (b) and (c) being from about 0.7:1 to about 0.95:1, the molar ratio of the chloride in ethyl aluminum sesquichloride to the total aluminum content in (b) and (c) being from about 0.7:1 to about 1.

Abstract: A process for producing high cis-1,4-polybutadienes using a catalyst system based on a rare earth compound that exhibits improved catalytic activity is provided which process comprises polymerizing 1,3-butadiene in a polymerization medium comprising a hydrocarbon solvent at a temperature of from about 0.degree. C. to about 120.degree. C. in the presence of a catalyst system which is a mixture of (1) a rare earth carboxylate selected from the group of neodymium carboxylates wherein the carboxylate has from 4 to 12 carbon atoms, (2) an alkyl aluminum chloride selected from the group of compounds represented by the formulae R.sup.2 AlCl.sub.2, R.sup.2.sub.3 Al.sub.2 Cl.sub.3 and R.sup.2.sub.2 AlCl wherein R.sup.2 is a hydrocarbon residue having from 8 to 12 carbon atoms and (3) an organo aluminum compound of the formula R.sup.3.sub.2 AlH wherein R.sup.

Abstract: There is provided a process for the preparation of a high cis-1,4-polybutadiene with a reduced microgel content wherein a novel catalyst system consisting of (1) a nickel salt of a carboxylic acid, (2) a mixture of triethyl aluminum and an organoaluminum compound having the formula R.sub.3 Al, said mixture having an average composition Et.sub.3-x R.sub.x Al wherein Et is an ethyl group, x is a numeral from 0.1 to 2.9 and R is an alkyl group having 8 to 12 carbon atoms, and (3) a boron trifluoride etherate is used to polymerize 1,3-butadiene in an inert hydrocarbon.

Abstract: A process for producing high cis-1,4-polybutadienes wherein there is reduced gel formation is provided which process comprises: polymerizing 1,3-butadiene in a polymerization medium comprising an inert hydrocarbon solvent and water at a temperature of from about -30.degree. C. to about 60.degree. C. in the presence of a catalyst system which is a mixture of (1) a substantially anhydrous divalent cobalt salt, (2) diethyl aluminum chloride or ethyl aluminum sesquichloride and (3) an organo aluminum compound of the formula R.sub.3 Al wherein R is an alkyl group having from 8 to 12 carbon atoms and, optionally triethylaluminum, the molar ratio of chloride in the diethyl aluminum chloride plus (3) being from about 0.7:1 to about 1 and the molar ratio of chloride in the ethyl aluminum sesquichloride plus (3) being from about 0.7:1 to about 1.