Abstract: A process for the production of EPDM comprising reacting ethylene, propylene, ethylidene norbornene, and hydrogen, in the gas phase, in a fluidized bed, under polymerization conditions, in the presence of a catalyst system comprising:(a) the reaction product of a vanadium compound and a electron donor;(b) at least one modifier having the formula BX.sub.3 or AlR.sub.(3-a) X.sub.a wherein each R is alkyl or aryl and is alike or different; each X is independently chlorine, bromine, or iodine; and a is 0, 1, or 2,wherein components (a) and (b) are impregnated into an inorganic support;(c) a halocarbon promoter; and(d) a hydrocarbyl aluminum cocatalyst with the following proviso:(i) the partial pressure of ethylene is in the range of about 25 to about 200 psi;(ii) the molar ratio of propylene to ethylene is in the range of about 0.2:1 to about 2:1;(iii) the molar ratio of hydrogen to ethylene is in the range of about 0.0001:1 to about 0.01:1; and(iv) the amount of ethylidene norbornene is about 1.

Abstract: A process for the production of EPDM comprising reacting ethylene, propylene, ethylidene norbornene, and hydrogen, in the gas phase, in a fluidized bed, under polymerization conditions, in the presence of a catalyst system comprising:(a) a titanium based catalyst having the formula Mg.sub.a Ti(OR).sub.b X.sub.c (ED).sub.d whereinR is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms or COR' wherein R' is an aliphatic or aromatic hydrocarbon radical having 1 to 14 carbon atoms;each OR group is alike or different;each X is independently chlorine, bromine, or iodineED is an electron donora is 0.5 to 56;b is 0, 1, or 2;c is 2 to 116; andd is greater than 1.5 a+2;(b) at least one modifier having the formula BX.sub.3 or AlR.sub.(3-b) X.sub.