Abstract: An improved polymerization process for making essentially non-agglomerated ethylene polymers, especially EPR polymers, based on the use of a high activity vanadium catalyst, which utilizes an alkylated metal chain transfer agent to moderate the kinetics of the polymerization reaction so as to avoid formation of an undesirable amount of agglomerated polymer.

Abstract: Stereoregular polymers having a molecular weight distribution of less than 5.0 and an isotactic index in excess of 96 percent are produced by polymerizing an alpha-olefin having 3 to 8 carbon atoms in a low pressure gas phase fluid bed process at a temperature in excess of 80.degree. C. employing a heat stable catalyst system comprising (a) a solid catalyst component containing magnesium, titanium, halide and a polycarboxylic acid ester containing two coplanar ester groups attached to adjacent carbon atoms, as inside electron donor, (b) an organoaluminum cocatalyst, and (c) a silicon compound containing a silicon-oxygen-carbon linkage, as outside electron donor.

Abstract: A catalyst composition comprising:(i) a complex comprised of V.sub.2 X.sub.3 (ED).sub.m and AlCl.sub.2 R.sub.2 whereinX=Cl, Br, or I, or mixtures thereofED=an electron donor, which is an ether, a phosphine, a ketone, an isocyanide, or an ester, said electron donor having 2 to 20 carbon atomsR=an alkyl having up to 14 carbon atomsm=an integer from 3 to 6,said complex impregnated into an inorganic oxide support;(ii) sufficient trialkylaluminum compound adsorbed on the inorganic oxide support to provide a molar ratio of adsorbed trialkylaluminum compound to vanadium of about 2.5:1 to about 10:1;(iii) a halocarbon promoter; and(iv) a hydrocarbyl aluminum cocatalyst.