Flaws Generated upon Two-Stage Solid-State Coextrusion of Ultrahigh Molecular Weight Polyethylene Reactor Powder.

Solid-state 1H-NMR relaxation behavior for ultra-high-molecular-weight polyethylene reactor powders with different morphologies

The relaxation behaviors of several commercial ultra-high-molecular-weight polyethylene (UHMW-PE) reactor powders were compared. The surface and internal morphologies of these powders were characterized by scanning and transmission electron microscopy observations. On the basis of these morphological analyses, the reactor powder consisted of particles and fibrils between them, the relative amou...

Unsteady-State Modeling of the Fluidized Bed Polyethylene Reactor

Synthesis of high molecular weight polyethylene using FI catalyst

A FI Zr-based catalyst of bis[N-(3,5-dicumylsalicylidene)-2′,6′­diisopropylanilinato]zirconium(IV) dichloride was prepared and used for polymerization of ethylene. The effects of reaction conditions on the polymerization were examined in detail. The increase in ethylene pressure and rise in polymerization temperature up to 35 oC were favorable for catalyst/MAO to raise the catalytic activity as...

Fixation of ultrahigh-molecular-weight polyethylene liners to metal-backed acetabular cups.

Locking mechanisms and metal-liner interface surfaces of six modular acetabular systems were evaluated to determine their effect on micromotion and backside wear of the polyethylene liner. Rotational and axial motion between the metal shell and polyethylene liner was measured in the Duraloc (DePuy, Warsaw, IN), Harris-Galante (Zimmer, Warsaw, IN), Impact (Biomet, Warsaw, IN), Lip Loc (Biomet), ...

Surfactant Effects on Structure and Mechanical Properties of Ultrahigh-Molecular-Weight Polyethylene/Layered Silicate Composites.

In this study, the reinforcement of ultrahigh-molecular-weight polyethylene (UHMWPE) with biotite was investigated. The biotite filler was mechanically activated with different dry surfactants to improve its compatibility with UHMWPE and decrease agglomeration among biotite particles. Alkyldimethylbenzylammonium chloride (ADBAC) and cetyltrimethylammonium bromide (CTAB) were selected as cationi...