Abstract: A novel catalyst and process for producing highly-crystalline polypropylene or pure block or terminal block types of copolymers of propylene and ethylene or propylene and another alpha-olefin in excellent yields which coproduce minor amounts of low-molecular-weight and, particularly, amorphous polymers. The catalyst comprises an aluminum alkyl compound, titanium trichloride, a sterically-hindered cyclic amine and an organotin sulfide. This novel catalyst and process are useful in polymerization techniques which use a polymerization medium or those in which the condensed monomer is polymerized from the liquid phase or those in which polymerization is accomplished from monomer substantially in the vapor phase.

Abstract: In an alpha-olefin polymerization process using a transition metal halide-aluminum alkyl catalyst system, addition of minor, effective amounts of alkyl orthoformates, thiophosphates and borates decreases the amount of low molecular weight or amorphous polymer produced.

Abstract: In an alpha-olefin polymerization process using a transition metal halide-aluminum alkyl catalyst system, addition of minor, effective amounts of a sterically hindered 5- or 6-membered cyclic ether decreases the amount of low molecular weight or amorphous polymer produced.

Abstract: In an alpha-olefin polymerization process using a transition metal halide-aluminum alkyl catalyst system, addition of minor, effective amounts of aromatic amines or amine N-oxides substituted with electron withdrawing groups decreases the amount of low molecular weight or amorphous polymer produced.

Abstract: Disubstituted heterocyclic amine oxides substituted alpha, alpha' to the N atom have been found to markedly reduce production of alkane-soluble components formed during the polymerization of propylene and its mixtures with titanium chloride-organoaluminum catalyst.

Abstract: A novel catalyst for producing crystalline poly alpha-olefins in excellent yields which coproduces substantially zero percent of low-molecular-weight and amorphous polymers is herein described. This novel catalyst is useful in polymerization techniques which use a solvent or those in which condensed monomer is the liquid phase or those in which polymerization is accomplished using monomer substantially in the vapor phase.