High molecular weight polyolefins

General Description Polybutene-1 (PB-1) is a polyolefin, or unsaturated polymer, that is expressed as C H2n- Basell Polyolefins series polybutene-1 resins are high-molecular-weight polyolefins manufactured from butene-1 monomer. Available as a homopolymer or a random copolymer.t Polybutene is a polymer of butylene and is also called polybutylene. 

MAXIMUM PROPERTIES ACHIEVED BY UNIAXIAL DRAWING OF HIGH MOLECULAR WEIGHT POLYOLEFINS... 

The detailed study by Fritz [44] concluded that transport by normal stresses only could be as much as two orders of magnitude lower than a corresponding system with forced feed. In addition, substantial temperature gradients developed in the polymer, causing substantial degradation in high molecular weight polyolefins. The scant market acceptance of the elastic melt extruder would tend to confirm Fritz s conclusions. 

Several polymer processing aids (PPA) are available to eliminate or reduce melt fracture. An effective method to eliminate melt fracture in high molecular weight polyolefins is to add a small amount of fluoroelastomer [153], about 500 to 1000 ppm (parts per million). When a fluoroelastomer PPA is added to a polyolefin it usually takes a certain amount of time for a critical coating of fluoropolymer to form on the die. This conditioning time can vary from 5 minutes to more than 1 hour [154]. 

Single-Site Organochromium Catalysts for High Molecular Weight Polyolefins... 

Cao J, Gao X, Shen K (2012) Morphologies and mechanical properties of high-density polyethylene induced by the addition of small amounts of both low- and high-molecular-weight polyolefin under shear stress applied by dynamic packing injection molding. J Macromol Sci Part B 51 2519-2526... 

Hashimoto A, Yagi K, Mantoku H (2000) Porous film of high molecular weight polyolefin and process for producing same. US Patent 6,048,607... 

Yoon, J., Mathers, R.T., Coates, G.W., and Thomas, E.L. (2006) Optically transparent and high molecular weight polyolefin block copolymers toward self-assembled photonic band gap materials. Macromolecules, 39,1913-1919. 

Late transition metal catalysts that are highly active and produce high molecular weight polyolefins were recently reported [198,199]. For example, nickel and palladium-diimine catalysts 67 produce highly branched polyethylene that is totally different from those produced by conventional or homogeneous Ziegler-Natta catalysts [200]. On the other hand, iron and cobalt 2,6-pyridine bis(imine) complexes 68 give linear polyethylene [201,202]. These catalysts are used with co-catalysts such as MAO, and the active species are cationic. Neu-... 

Broadens extrusion processing capabilities of polyolefin resins Ideal for use in high viscosity, high molecular weight polyolefins... 

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