In some embodiments, ethylene-propylene random copolymers as viscosity modifiers were synthesized with pyridyldiamido catalyst systems and a chain transfer agent. In some embodiments, the present disclosure provides for ethylene-propylene random copolymers having an ethylene content between about 45 wt % and about 55 wt %. In some embodiments, the ethylene-propylene random copolymer is used as a viscosity modifier in a lubricating composition and a fuel composition.

In some embodiments, ethylene-propylene random copolymers as viscosity modifiers were synthesized with pyridyldiamido catalyst systems and a chain transfer agent. In some embodiments, the present disclosure provides for ethylene-propylene random copolymers having an ethylene content between about 45 wt % and about 55 wt %. In some embodiments, the ethylene-propylene random copolymer is used as a viscosity modifier in a lubricating composition and a fuel composition.

A process for preparing a polydiene, the process comprising (i) forming an active catalyst composition by combining a rare-earth compound, an alkylating agent, an aluminoxane, and a halogen compound; and (ii) combining the active catalyst composition with monomer to be polymerized within 12 hours of forming the active catalyst composition.

A process for preparing a polydiene, the process comprising (i) forming an active catalyst composition by combining a rare-earth compound, an alkylating agent, an aluminoxane, and a halogen compound; and (ii) combining the active catalyst composition with monomer to be polymerized within 12 hours of forming the active catalyst composition.

Embodiments of methods for producing a trimodal polymer in a solution polymerization process comprise three solution polymerization reactors organized in parallel or in series.

Embodiments of methods for producing a trimodal polymer in a solution polymerization process comprise three solution polymerization reactors organized in parallel or in series.

Embodiments of methods for producing a trimodal polymer in a solution polymerization process comprise three solution polymerization reactors organized in parallel or in series.

The present invention relates to a gas/liquid oligomerization reactor with successive zones of variable diameter. The invention also relates to a process for the oligomerization of ethylene using a gas/liquid oligomerization reactor with successive zones of variable diameter.

The present invention relates to a gas/liquid oligomerization reactor with successive zones of variable diameter. The invention also relates to a process for the oligomerization of ethylene using a gas/liquid oligomerization reactor with successive zones of variable diameter.

A perfluorodiacyl peroxide represented by the following formula (1):
(C.sub.5F.sub.11COO).sub.2   (1).
Also disclosed is a solution containing the perfluorodiacyl peroxide, a polymerization initiator containing the perfluorodiacyl peroxide, a method for producing a polymer which includes polymerizing a radically polymerizable monomer with the perfluorodiacyl peroxide, and a perfluoroacyl chloride represent by the following formula (2):
C.sub.5F.sub.11COCl (2).