Wear-Resistant Ultrahigh-Molecular-Weight Polyethylene-Based Nano- and Microcomposites for Implants

Abstract

The influence of modification by hydroxyapatite (HA) nano- and microparticles on tribotechnical properties of ultrahigh-molecular-weight polyethylene (UHMWPE) was investigated to develop polymer implants for endoprosthesis. It was shown that modification of UHMWPE by hydroxyapatite nanoparticles within range of 0.1–0.5 wt.% results in increase of wear resistance at dry sliding by 3 times. On the other hand adding of 20 wt.% of micron size HA gives rise to the same effect. The effect of increasing wear resistance is not substantially changed at surface treatment of the nano- and microcomposites by N+ion beams as compared with nonirradiated blends. Preliminary joint mechanical activation of UHMWPE powder and fillers results in more uniform distribution of nanofillers in the matrix and, as a result, formation of more ordered structure. Structure within bulk material and surface layers was studied by means of optical profilometry, scanning electron microscopy, infrared spectroscopy, and differential scanning calorimetry. It is shown that adding of hydroxyapatite nanoparticles and high-energy surface treatment of the composite by N+ion implantation improve tribotechnical properties of UHMWPE due to formation of chemical bonds in the composite (crosslinking) and ordering of permolecular structure.

Increasing the wear resistance of ultra-high molecular weight polyethylene by adding solid lubricating fillers

“…Wear intensity I and roughness of wear track surface Ra of UHMWPE and composites on its basis. Steady-state stage for conditions of dry sliding friction: ( ) pure UHMWPE (1), UHMWPE + 3 wt.% of (2), UHMWPE + 5 wt.% of (3), UHMWPE + 10 wt.% of (4); (b) pure UHMWPE (1), UHMWPE + 3 wt.% of MoS 2 (2), UHMWPE + 5 wt.% of MoS 2 (3), UHMWPE + 10 wt.% of MoS 2 (4) Abrasive wear. The influence of the fillers (C, MoS 2 and PTFE) on the abrasive wear resistance of UHMWPEbased microcomposites was also analyzed.…”

“…Currently, UHMWPE-based microand nanocomposites are being intensively developed. The certain types and sizes of fillers are defined by the range of application and environment where the composites are to be used (vacuum, reactive and inert environment, cryogenic or elevated temperatures) [1][2][3][4].…”

The Effect of Adding Calcium Stearate on Wear-resistance of Ultra-high Molecular Weight Polyethylene

“…Namely the usage of the composite materials based on ultra-high molecular weight polyethylene (UHMWPE) allows increasing the abrasion resistance of metallopolymeric tribounits in multiples. Recently UHMWPE-based micro-and nanocomposites have been developed dynamically [4][5][6][7][8]. For instance, when manufacturing solid lubrication composites, dispersed fillers, graphite and molybdenum disulfide, are added into a polymer matrix to expand the usability of antifriction composites in the highly-loaded friction units when liquid or paste lubricants do not endure operating conditions.…”

Wear resistance of composites based on ultrahigh molecular weight polyethylene filled with graphite and molybdenum disulfide microparticles

“…The use of UHMWPE based materials makes it possi ble to increase the wear resistance of metal-polymer tribojoints by several times. UHMWPE based micro and nanocomposites have been extensively developed in recent years [4][5][6][7][8]. However, mechanisms of the high wear resistance of compositions based on the high molecular weight matrix are not yet perfectly under stood [6].…”