Polyethylene ultra-high molecular weight form

ISO 5834-1 1998 Implants for surgery - Ultra-high molecular weight polyethylene - Part 1 Powder form... 

Copolymer ethylene-dimethyl-aminoethyl methacrylate (EDAM) with 3.9% DAM side groups and ultra-high molecular weight polyethylene (UHMWPE) were blended in decalin solvent. The hot homogenized solution was poured into an aluminum tray to form gels and the decalin was allowed to evaporate from the... 

At a conceptual level, polyethylene consists only of carbon and hydrogen, as was described in the previous chapter. However, if the discussion of polyethylene is to proceed from ideal abstractions to actual physical implants, three "real world" steps need to occur. First, the ultra-high molecular weight polyethylene (UHMWPE) must be polymerized from ethylene gas. Second, the polymerized UHMWPE, in the form of resin powder, needs to be consolidated into a sheet, rod, or near-net shaped implant (Figure 2.1). Finally, in most instances, tire UHMWPE implant needs to be machined into its final shape (Figure 2.1). A small subset of implants are consolidated into their final form directly, in a process known as direct compression molding (DCM), witiiout need of additional machining. 

The continuous extrusion of the solution of ultra high molecular weight polyethylene (UHMWPE) with a huge jump in viscosity when the solution is formed. 

A gel network which involves folded-chain, lamellar crystals can be obtained by cooling a semi-dilute solution of ultra-high molecular weight polyethylene (UHMW-PE). The usual chain-folded crystallization occurs, but, because of the high molecular weight, complete disentanglement with the resulting crystal precipitation is prevented, and a gel network forms, provided that each lamella is connected... 

F648-14 Standard specification for Ultra-High-Molecular-Weight Polyethylene Powder and Fabricated Form for surgical implants... 

F2695-12 Standard specification for ultra-high molecular weight Polyethylene Powder Blended with Alpha-Tocopherol (Vitamin E) and Fabricated Forms for surgical implant applications... 

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