Ultra high density molecular weight

High molecular weight HOPE is a special class of linear resins with molecular weights in the 200,000 to 500,000 range. Ultra high density polyethylene has an average molecular weight of over 3 million. 

Low-density Medium-density High-density Ultra high-molecular-weight Glass-fiber- reinforced, high-density Ethylene-vinyl acetate copolymer... 

Additive-free film samples of isotactic polypropylene (iPP, 30pm Himont Profax resin) and polyethylenes (LLDPE, 120ym, linear low density DuPont Sclair resin, and UHMW-PE, 120wm, ultra high molecular weight, high density Himont LSR 5641-1B resin) were oxidized by exposure in air to y-radiation (AECL Gamma Cell 220, 1.0... 

Polymer Engineering and Science 30,No.l3,Mid-My 1990,p.783-97 LOW DENSITY FOAMS PRODUCED FROM SHEARED ULTRA-HIGH-MOLECULAR-WEIGHT POLYETHYLENE GELS Matthews F M Hoffman D M LAWRENCE LIVERMORE NATIONAL LABORATORY... 

Within the family of polyolefins there are many individual families that include low density polyethylenes, linear low density polyethylenes, very low polyethylenes, ultra low polyethylenes, high molecular weight polyethylenes, ultra high molecular weight polyethylenes, polyethylene terephthalates, ethylene-vinyl acetate polyethylenes, chlorinated polyethylenes, crosslinked polyethylenes, polypropylenes, polybutylenes, polyisobutylene, ionomers, polymethylpentene, thermoplastic polyolefin elastomers (polyolefin elastomers, TP), and many others. 

Microcosm size and type 60-cm deep X 17-cm diameter plastic pipe made of ultra-high molecular weight, high density, and nonplasticized polyethylene and containing an intact soil core covered by homogenized topsoil tube sits on a Buchner funnel covered by a thin layer of glass wool... 

Blends of LLDPE/PP = 50 50, with or without compatibilizing ethylene-propylene copolymer, EPR, were studied by Dumouhn et al. [1984]. In spite of the expected immiscibihty, the blends showed additivity of properties with good superposition of the stress growth functions in shear and elongation, as well as with the zero deformation rate Trouton ratio, Rj, = 1. In earlier work, blends of medium density PE (MDPE) with small quantities of ultra-high molecular weight polyethylene (UHMWPE) were studied in shear and extension. Again, SH and Rj, = 1 were observed. 

High density zirconia oxide showed excellent compatibihty with autogenous rhesus monkey bone and was completely nonreactive to the body environment for the duration of the 350 day study [Hentrich et al, 1971]. Zirconia has shown excellent biocompatibihty and good wear and friction when combined with ultra-high molecular weight polyethylene [Kumar et al., 1989 Murakami and Ohtsuki, 1989]. 

Carbon fibers have been incorporated in the high density polyethylene used in total knee replacements (Figure 41.5). The standard ultra high molecular weight polyethylene (UHMWPE) used in these implants... 

Y. Chen, H. Zou, M. Liang, P. Liu, Rheological, thermal, and morphological properties of low-density polyethylene/ultra-high-molecular-weight polyethylene and linear low-density polyethylene/ultra-high-molecular-weight polyethylene blends. J. Appl. Polym. Sci. 129, 945-953 (2013)... 

UHMWPE, ultra-high-molecular-weight high-density polyethylene... 

Aramid and ultra-high molecular weight polyethylene are used extensively as base materials for ballistic protection. As discussed earlier (section 7.3.1), these high performance fibres are characterised by high strength, high eneigy absorption, and low density. However, to meet the protection requirements for typical ballistic threats, approximately 13-50 layers of fabric are required, which results in a bulky and stiff armour. The bulk-iness limits its comfort and has resfiicted its appUcation primarily to torso protection. 

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