Friction and Wear Behavior of Ultra-High Molecular Weight Polyethylene as a Function of Polymer Crystallinity

Abstract

In this study the friction and wear behavior of medical grade ultra-high molecular weight polyethylene (UHMWPE) (GUR 1050 resin) were evaluated as a function of polymer crystallinity. Crystallinity was controlled by heating UHMWPE samples to a temperature above its melting point and varying the hold time and cooling rates. Degree of crystallinity of the samples was evaluated using differential scanning calorimetry (DSC). Quantitative friction experiments were conducted at two different scales. A custom-made microtribometer with commercially available spherical Si3N4 probes in dry conditions was used to test friction at the microscale. An atomic force microscope with commercially available Si3N4 probes under dry conditions was used for nanoscale experiments. A higher degree of crystallinity in the UHMWPE resulted in lower friction force and an increase in scratch resistance at both scales. Reciprocating wear tests preformed using the tribometer show that higher crystallinity also results in lower friction, as well as lower wear depth and width.

Friction and wear behavior of ultrahigh molecular weight polyethylene as a function of crystallinity in the presence of the phospholipid dipalmitoyl phosphatidylcholine

“…Wear behavior was also affected by the addition of DPPC into the tribological environment, Based on profilometer depth measurements, the HC‐PE sample showed higher wear resistance than LC‐PE in the control and DPPC‐lubricated reciprocating tests (Table II). The increased wear resistance of HC‐PE compared with LC‐PE in the control can be attributed to the increased hardness associated with increased crystallinity in UHMWPE 24. The presence of DPPC in the lubricant corresponded with decrease in wear depth only for the higher crystallinity sample.…”

“…One potential for increasing adsorption of SAPL onto UHMWPE is to increase the crystallinity of the material. The authors have studies the effect of crystallinity on the friction and wear behavior of UHMWPE in dry conditions and found that increased crystallinity resulted in lower friction and wear 24…”

Tribological performance of hygrothermally aged UHMWPE hybrid composites

“…DSC analyses were performed using a Mettler Toledo DSC to determine the degree of crystallinity and melting temperature of the polymer composites before and after aging. This information is relevant as it holds information about the polymer structure, and it has been shown that the degree of crystallinity of polymers affect their mechanical properties and consequently their tribological performance [68].…”

“…Semi-crystalline polymer mechanical properties depend on the crystallinity of the material, as they are dependent on how the polymer structure is distributed and the proportion of organized and random form. Moreover, the mechanical properties affect the tribological behavior, so the varying the crystallinity of a polymer may affect the tribological performance, which was identified by Karuppiah et al when studying the friction and wear of UHMWPE [68].…”

Roughness, Wear and Thermal Analysis of UHMWPE Nanocomposites Asacetabular Cup in Hip Joint Replacement

“…The improving of wear resistance is related to cross-linking and reinforced materials that affecting the atomic or molecular arrangement, confirming a specific crystal structure [13]. Karuppiah et al discovered that the crystallinity effects on the wear resistance through increasing the crystallinity that decreases the friction force and the scratch depth [14]. Similar results were suggested by Wang and Ge [15].…”