A homopolypropylene has i) a molecular weight distribution of less than 2.4; ii) a melt index (measured at 230° C. under a load of 2.16 kg in accordance with ASTM D1238) of 5 to 3000 g/10 min; iii) a remaining stress ratio of 0.5% or less; and iv) a complex viscosity of 5 to 600 Pa.Math.s at an angular frequency of 1 rad/s and a complex viscosity of 5 to 300 Pa.Math.s at an angular frequency of 100 rad/s. A method for preparing the homopolyproylene is also provided. A molded article and a non-woven fabric are also provided.

The present disclosure relates to processes for producing a catalyst composition. A process may include mixing a catalyst compound having a transition metal atom, an activator, and a support to form a supported catalyst mixture. A process may also include drying the supported catalyst mixture at a pressure of about 10 kPa or less and a temperature of about 60° C. or greater for a period of about 6 h or less. The present disclosure also relates to processes for producing polyolefins. A process may include introducing a catalyst composition and at least one olefin to a polymerization reactor, where the catalyst composition has about 0.5 wt % to about 1.5 wt % aromatic hydrocarbon content, and less than 1 wt % of aliphatic hydrocarbon content. A process may also include obtaining a polyolefin having about 300 ppb or less aromatic hydrocarbon.

Polymerization process control methods for making polyethylene are provided. The process control methods include performing a polymerization reaction in a polymerization reactor to produce the polyethylene, where ethylene, and optionally one or more comonomers, in the polymerization reaction is catalyzed by an electron donor-free Ziegler-Natta catalyst and an alkyl aluminum co-catalyst. A melt flow ratio (I.sub.21/I.sub.2) of the polyethylene removed from the polymerization reactor is measured and an amount of long chain branching (LCB) of the polyethylene from the polymerization reactor is controlled by adjusting a weight concentration of the alkyl aluminum co-catalyst present in the polymerization reactor. In addition, an electron donor-free Ziegler-Natta catalyst productivity of the polyethylene being produced in the polymerization reactor is measured from which the amount of LCB of the polyethylene from the polymerization reactor is determined using the measured electron donor-free Ziegler-Natta catalyst productivity and a predetermined relationship between the electron donor-free Ziegler-Natta catalyst productivity and the LCB.

A solution polymerization process uses a reactor system in which a first stage is operated in a non adiabatic (cooled) manner and is connected to a second stage containing a downstream reactor that is operated adiabatically. In an embodiment, the first reactor stage includes at least one loop reactor and the second stage includes a tubular reactor. In an embodiment, the first stage is operated with a single site catalyst and at least one downstream reactor uses a Ziegler Natta catalyst.

A polymerization catalyst system, a method of using the polymerization catalyst system, and a polymer produced with the catalyst system. The polymerization catalyst system has a non-metallocene catalyst and a metallocene catalyst. The metallocene catalyst has the formula:

##STR00001##

wherein R.sup.1 and R.sup.2 are each independently, phenyl, methyl, chloro, fluoro, or a hydrocarbyl group.

The present disclosure provides processes for polymerizing olefin(s). Methods can include contacting a first composition and a second composition in a line to form a third composition. The first composition can include a contact product of a first catalyst, a second catalyst, a support, a first activator, a mineral oil. The second composition can include a contact product of an activator, a diluent, and the first catalyst or the second catalyst. Methods can include introducing the third composition from the line into a gas-phase fluidized bed reactor, introducing a condensing agent to the line and/or the reactor, exposing the third composition to polymerization conditions, and/or obtaining a polyolefin. Polyethylene compositions including at least 65 wt % ethylene derived units, based upon the total weight of the polyethylene composition, are provided.

The invention relates to power cable polymer composition which comprises a thermoplastic polyethylene having a chlorine content which is less than X, wherein X is 10 ppm, a power cable, for example, a high voltage direct current (HV DC), a power cable polymer insulation, use of a polymer composition for producing a layer of a power cable, and a process for producing a power cable.

A catalyst component for olefin polymerization includes magnesium, titanium, a halogen, an internal electron donor compound, and a precipitation aid. The precipitation aid includes a precipitation aid represented by general formula (I). The precipitation aid represented by general formula (I) includes isomers represented by general formula (I-a) and/or (I-b).

##STR00001##

Catalyst systems and methods for making and using the same. A method of polymerizing olefins to produce a polyolefin polymer with a multimodal composition distribution, includes contacting ethylene and a comonomer with a catalyst system. The catalyst system includes a first catalyst compound and a second catalyst compound that are co-supported to form a commonly supported catalyst system. The first catalyst compound includes a compound with the general formula (C.sub.5H.sub.aR.sup.1.sub.b)(C.sub.5H.sub.cR.sup.2.sub.d)HfX.sub.2. The second catalyst compound includes at least one of the following general formulas:

##STR00001##

In both catalyst systems, the R groups can be independently selected from any number of substituents, including, for example, H, a hydrocarbyl group, a substituted hydrocarbyl group, or a heteroatom group, among others.

Disclosed herein are ethylene-based polymers produced using dual metallocene catalyst systems. These polymers have low densities, high molecular weights, and broad molecular weight distributions, as well as having the majority of the long chain branches in the lower molecular weight component of the polymer, and the majority of the short chain branches in the higher molecular weight component of the polymer. Films produced from these polymers have improved impact and puncture resistance.