A polyethylene blend comprising a uniform dispersion of constituents (A) and (B): (A) a Ziegler-Natta catalyst-made linear low density polyethylene and (B) a metallocene catalyst-made linear low density polyethylene, a composition comprising the polyethylene blend and at least one additive, methods of making and using same, and manufactured articles and films comprising or made from same.

Provided are a highly insulated rubber composition, a processing method therefor, and an application thereof. The rubber composition comprises a rubber matrix and compounding components. In parts by weight, every 100 parts of said rubber matrix comprise: 50-95 parts of a chlorinated (and/or chlorosulfonated) polyethylene rubber, 5-50 parts of a highly branched polyethylene, and 0-30 parts of an ethylene propylene rubber; and, the branching degree of the highly branched polyethylene is not lower than 50 branches/1000 carbon atoms. The compounding components contain a vulcanization system. The rubber composition improves the electrical insulation performance of the chlorinated (and/or chlorosulfonated) polyethylene rubber, so that the rubber composition is more suitable for the applications with high requirements for electrical insulation.

Disclosed are an aging-resistant rubber composition and a processing method therefor and use thereof. The rubber composition includes a rubber matrix and compounding components, and in parts by weight, every 100 parts of said rubber matrix comprise 50-99 parts of a halogenated butyl rubber, 0-50 parts of a highly branched polyethylene P1, and 0-50 parts of P2 obtained by the polarization modification of said highly branched polyethylene P1, and the sum of P1 and P2 in parts by weight is 1-50 parts; and said compounding components comprise a vulcanization system. The rubber composition improves the heat aging resistance of the halogenated butyl rubber, making it more suitable for high temperature environments, and also improves the properties of the halogenated butyl rubber which are related to the halogen content, such as the adhesiveness, oil resistance, flame retardancy and the like, by adjusting the extent of halogenation of the highly branched polyethylene which is employed in combination, thereby overcoming the limitation caused by the halogen content of the halogenated butyl rubber.

Disclosed is a rubber composition and a tire using the same. The rubber composition comprises a rubber matrix and a compounding component. In parts by weight, every 100 parts by weight of said rubber matrix comprises 5-95 parts by weight of a branched polyethylene, 5-90 parts by weight of a highly unsaturated diene elastomer and 0-30 parts by weight of a low unsaturated diene elastomer; and said compounding component comprises a vulcanization system and a filler. The rubber composition has good aging resistance and mechanical properties, and can be applied for products such as tires, rubber hoses, rubber tapes and so on, in which the traditional, easily aging diene rubber was commonly used.

The present invention relates to a polyolefin composition comprising: a) at least one first polyolefin having a multimodal molecular weight distribution and prepared in the presence of at least one metallocene catalyst; and b) at least one second polyolefin having a M.sub.w/M.sub.n of at least 10.0 and a long chain branching index g.sub.rheo of at least 0.85, wherein said second polyolefin is present in an amount of at least 1.0% by weight based on the total weight of the polyolefin composition; wherein the second polyolefin has a High Load Melt Index of at least 0.60 times the High Load Melt Index HLMI of the first polyolefin and of at most 1.40 times the High Load Melt Index HLMI of the first polyolefin, as measured following the procedure of ISO 1133 condition G using a temperature of 190° C. and a load of 21.6 kg. The present invention also relates to processes for preparing said composition, and articles made therefrom.

The present invention relates to a polyolefin composition comprising: a) at least one polyolefin having a multimodal molecular weight distribution and prepared in the presence of at least one metallocene catalyst; and b1) at least 0.5% by weight of silica nanoparticles based on the total weight of the polyolefin composition. The present invention also relates to articles comprising said polyolefin composition and to processes for preparing said compositions and articles.

The invention provides a composition comprising a first composition, comprising a first ethylene/alpha-olefin/non-conjugated polyene and a second ethylene ethylene/alpha-olefin/non-conjugated polyene, and wherein the first composition comprises the following property: Mw>1389.6 [g/mole] MV+115,000 g/mole, wherein MV is the Mooney Viscosity (ML 1+4, 125C), and Mw is the weight average molecular weight, as determined by conventional GPC.

Provided herein are methods of making blended polymer compositions having enhanced elasticity. The present methods comprise the steps of producing a first polymer composition using a VTP catalyst system, producing a second polymer composition using a HMP catalyst system and combining the first polymer composition and the second polymer composition to make the blended polymer composition. The present methods include blending/combining the polymer compositions produced by different catalyst systems. One such catalyst system includes (i) a vinyl-terminated polymer (VTP) catalyst system comprising a VTP catalyst compound (referred to herein also as a “VTP catalyst”) and one or more activators. Another catalyst system includes a high molecular-weight polymer (HMP) catalyst system comprising a HMP catalyst compound (referred to herein also as a “HMP catalyst”) and one or more activators. The activators of these different catalyst systems can be the same or different in whole or in part.

The present invention relates to a process for the production of an ethylene-propylene-diene terpolymer (EPDM) composition in a reaction vessel comprising the following steps in this order: (a) supplying a quantity of a first composition comprising an ethylene copolymer or a propylene copolymer and a first peroxide to the reaction vessel; (b) supplying a quantity of a second composition comprising EPDM and a second peroxide to the reaction vessel; or (a) supplying a quantity of a second composition comprising EPDM and a second peroxide to the reaction vessel; (b) supplying a quantity of a first composition comprising an ethylene copolymer or a propylene copolymer and a first peroxide to the reaction vessel; and (c) exposing the contents of the reaction vessel under stirring to a temperature of 100-200 C.; wherein the ethylene copolymer is a copolymer comprising polymeric units derived from ethylene and polymeric units derived from a mono-olefinic compound comprising 3 to 10 carbon atoms, and wherein the propylene copolymer is a copolymer comprising polymeric units derived from propylene and polymeric units derived from a mono-olefinic compound comprising 2 carbon atoms or 4-10 carbon atoms. Such process allows for the production of an oil-extended EPDM composition having a certain high Mooney viscosity whilst still using an EPDM as obtained from the polymerisation process having a relatively moderate Mooney viscosity.

In an embodiment, a thermoplastic vulcanizate (TPV) composition is provided. The TPV composition includes a thermoplastic polyolefin; and an ethylene based copolymer rubber, wherein the ethylene based copolymer rubber has: a Mw of from 500,000 g/mol to 3,000,000 g/mol, a Mw/Mn of 4.0 or lower, and a g.sub.vis of 0.90 or greater. In another embodiment, a TPV composition includes a thermoplastic phase and an ethylene-propylene-diene terpolymer, wherein the thermoplastic vulcanizate composition has: a hardness of from 20 Shore A to 60 Shore D; and a stress relaxation slope of 1 to 5 (1/min) as measured by an Elastocon stress relaxation instrument.