Abstract: Improved multi-phase polypropylene composites are provided. The compositions are comprised of a polypropylene base resin, a non-compatible dispersed phase which can be a polymer or filler material and a propylene-ethylene copolymer grafted with a carboxylic acid or carboxylic acid derivative.

Abstract: A high molecular weight, medium density polyethylene (HMW, MDPE) is disclosed. The polyethylene comprises from about 85 to about 98 wt % of recurring units of ethylene and about 2 to about 15 wt % of a C3-C10 &agr;-olefin. It has a density from about 0.92 to about 0.944 g/cc, a melt index MI2 from about 0.01 to about 0.5 dg/min, and a melt flow ratio MFR from about 50 to about 300. It has a multimodal molecular weight distribution comprising a high molecular weight component and a low molecular weight component. The low molecular weight component has an MI2 from about 50 to about 600 dg/min and a density from about 0.94 to about 0.97 g/cc. A process for making the medium density polyethylene is also disclosed. The process uses a Ziegler catalyst and applies multiple reaction zones.

Abstract: A high molecular weight, medium density polyethylene (HMW, MDPE) is disclosed. The polyethylene comprises from about 85 to about 98 wt % of recurring units of ethylene and about 2 to about 15 wt % of a C3-C10 &agr;-olefin. It has a density from about 0.92 to about 0.944 g/cc, a melt index MI2 from about 0.01 to about 0.5 dg/min, and a melt flow ratio MFR from about 50 to about 300. It has a multimodal molecular weight distribution comprising a high molecular weight component and a low molecular weight component. The low molecular weight component has an MI2 from about 50 to about 600 dg/min and a density from about 0.94 to about 0.97 g/cc. A process for making the medium density polyethylene is also disclosed. The process uses a Ziegler catalyst and applies multiple reaction zones.

Abstract: A high molecular weight, medium density polyethylene (HMW, MDPE) is disclosed. The polyethylene comprises from about 85 to about 98 wt % of recurring units of ethylene and about 2 to about 15 wt % of a C3-C10 &agr;-olefin. It has a density from about 0.92 to about 0.944 g/cc, a melt index MI2 from about 0.01 to about 0.5 dg/min, and a melt flow ratio MFR from about 50 to about 300. It has a multimodal molecular weight distribution comprising a high molecular weight component and a low molecular weight component. The low molecular weight component has an MI2 from about 50 to about 600 dg/min and a density from about 0.94 to about 0.97 g/cc. A process for making the medium density polyethylene is also disclosed. The process uses a Ziegler catalyst and applies multiple reaction zones.

Abstract: An olefin polymerization process is described. The process comprises polymerizing an olefin in the presence of a supported single-site catalyst, an optional activator, and a fatty amine. The fatty amine is added at a concentration in the range from about 10 to about 75 weight percent based on the weight of the supported catalyst. The fatty amine helps to reduce fouling and sheeting during the polymerization process and enhances catalyst activity.

Abstract: A process for producing a polyethylene film composition, comprising melt extruding a linear copolymer of ethylene and at least one other olefin having from 3 to 8 carbon atoms, said linear copolymer having a bimodal distribution comprising a high molecular weight fraction having a weight average molecular weight of at least 600,000 and a low molecular weight fraction having a weight average molecular weight of less than 20,000 at a temperature of from 195 to 285.degree. C. in the presence of oxygen in an amount of from about 0.5 to about 6% by volume to improve bubble stability without any significant reduction in tear strength of film produced from said melt extruded linear copolymer.

Abstract: A multiple stage or multiple zone process for making olefin polymers is disclosed. A single-site catalyst, preferably one that contains a heteroatomic ligand, is used in the first stage or zone, and a Ziegler-Natta catalyst is used at a higher temperature in later stages or zones. A parallel multiple zone process is also described. The processes, which can be performed adiabatically, give polymers with improved thermal processing ability.

Abstract: A polyethylene film composition characterized as having a broad molecular weight distribution, Mw/Mm 15, a density of 0.920 to 0.970 g/cc, a melt flow index (190.degree. C./2.16 kg) of 0.01 to 0.2 g/10 min., the polyethylene film composition being produced by melt extruding a linear copolymer at a temperature of at least 180.degree. C. in the presence of an amount of a free radical initiator sufficient to improve bubble stability without any significant reduction in the tear strength of film produced from the composition as compared with film produced from the linear copolymer that has not been treated with the free radical initiator.