Ethylene - alpha olefin copolymers

U. Moll and M. Lux, Manufacture of ethylene/alpha olefin copolymers with metallocene catalysts in slurry loop... 

Advances in Polymer Technology 22, No.3, FaU 2003, p.209-17 BINARY BLENDS OF EVA AND METALLOCENE-CATALYZED ETHYLENE-ALPHA-OLEFIN COPOLYMERS AND THEIR... 

Blends of ethylene-vinyl acetate (EVA) copolymer with metallocene-catalysed elastomeric ethylene-alpha-olefin copolymer were investigated and were found to be immiscible in the melt and solid state but mechanically compatible. The morphology (SEM), thermal (DSC), rheological (viscosity), mechanical (including tensile, shear thinning and elastic behaviour) and optical properties of EVA-rich and ethylene-alpha-olefin copolymer-rich blends were studied and the results are discussed in terms of processibility in film applications. 24 refs. 

A foam comprising a blend of a low density polyethylene and an ethylene/alpha-olefin copolymer is disclosed. The ethylene/alpha-olefin copolymer is preferably LLDPE and has a density ranging from about 0.86 to 0.94 grams/cubic centimeter and a melt flow index of greater than 10 g/10 minutes. 

POE and polyolefin plastomers (POP) are ethylene alpha olefin copolymers produced using constrained geometry and metallocene catalyst. They differ from traditional polyolefins in that they have narrow molecular weight distribution and a regular placement of the octene co-monomer on the ethylene backbone. This highly uniform distribution allows for some unique plastic characteristics. 

Metallocene catalysis is an alternative to the traditional Ziegler-Natta vanadium-based catalysis for commercial polyolefin production, e.g. the use of metallocene-catalyzed ethylene alpha-olefin copolymers as viscosity index modifiers for lubricating oil compositions [23]. The catalyst is an activated metallocene transition metal, usually Ti, Zr or Hf, attached to one or two cyclopentadienyl rings and typically activated by methylaluminoxane. Metallocene catalysis achieves more stereo-regularity and also enables incorporation of higher alpha-olefins and/or other monomers into the polymer backbone. In addition, the low catalyst concentration does not require a cleanup step to remove ash. 

General Description Dow Chemicals Affinity resins, homogenous ethylene alpha-olefin copolymers, contain up to 20% octene comonomer. Affinity polyolefin plastomers (POPs) can be used in any of the extrusion technologies as a sealant, to deliver an unparalleled combination of low seal-initiation temperature, hot-tack strength, toughness, tear resistance, and transparency.f ... 

In the following patent heat sealable at 100 °C, blends were disclosed. They comprised 30-70 wt% ethylene-alpha-olefin copolymer prepared using a metallocene catalyst, VLDPE or plastomer [with density p = 880-915 kg m , ... 

L. B. Weaver et al.. Novel ethylene/alpha-olefin copolymers-polyproylene blends for... 

Mitsui Petrochemical Industries Ltd. Tafmer A/P ethylene/alpha-olefin copolymer product bulletin, 1986. 

Zhang, F.J., Song, M., Lu, T.J., Liir, J.P., He, T.B., The polydispersity of ethylene sequence in metallocene ethylene/alpha-olefin copolymers HI crystallization and melting behavior of short ethylene sequence, Polymer 2002, 43 1 453-1460. 

Starck, P., Malmberg, A., Lofgren, B., Thermal and rheological studies on the molecular composition and stmcture of metallocene-and Ziegler-Natta-catalyzed ethylene-alpha-olefin copolymers, J. Appl. Polym. Sci. 2002, 83 1140-1156. 

Starck, P., Rajanen, K., Lofgren, B., Comparative studies of ethylene-alpha-olefin copolymers by thermal fiactionations and temperature-dependent crystallinity measurements, Thermochim. Acta 2003, 395 169-181. 

Faldi A, Soares JBP. Characterization of the combined molecular weight and composition distribution of industrial ethylene/alpha-olefin copolymers. Polymer 2001 42 3057-3066. 

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