Ultra-High Molecular Weight Polyethylene: Influence of the Chemical, Physical and Mechanical Properties on the Wear Behavior. A Review

Abstract

Ultra-high molecular weight polyethylene (UHMWPE) is the most common bearing material in total joint arthroplasty due to its unique combination of superior mechanical properties and wear resistance over other polymers. A great deal of research in recent decades has focused on further improving its performances, in order to provide durable implants in young and active patients. From “historical”, gamma-air sterilized polyethylenes, to the so-called first and second generation of highly crosslinked materials, a variety of different formulations have progressively appeared in the market. This paper reviews the structure–properties relationship of these materials, with a particular emphasis on the in vitro and in vivo wear performances, through an analysis of the existing literature.

Nascent particle sizes and degrees of entanglement are responsible for the significant differences in impact strength of ultrahigh molecular weight polyethylene

“…Since their molecular weights were so close, there were only minor differences in their tensile, yield, and flexural strengths. The wear resistance of a UHMWPE sample is determined mainly by its molecular weight . The slight difference in wear resistance between SLL‐5 and GUR 4150 confirms that they had very similar molecular weights.…”

“…Ultrahigh molecular weight polyethylene (UHMWPE) is a member of the polyethylene (PE) family and has a molecular weight of over 1,000,000 g mol −1 , as defined by ISO 11542. As an engineering material, UHMWPE has many attractive physical and chemical properties, especially high impact strength and abrasion resistance, that are unparalleled among other polymeric materials . Many of the outstanding properties of UHMWPE are indeed closely related to its molecular weight …”

A rugged, self-sterilizing antimicrobial copper coating on ultra-high molecular weight polyethylene: a preliminary study on the feasibility of an antimicrobial prosthetic joint material

“…37 Crosslinking helps to restrict the mobility of the long polymeric chains and maintain the molecular structure, hence reduce the formation of the surface fibrils. 35,[38][39][40] Whereas residual free radicals interact with ambient oxygen and therefore cause breakdown of the polymeric structure. 36 Thermal treatment such as remelting is therefore used to resolve oxidative deconstruction.…”

Process Optimization of Ultra-High Molecular Weight Polyethylene/Cellulose Nanofiber Bionanocomposites in Triple Screw Kneading Extruder by Response Surface Methodology

“…Though, in comparison to other well-studied UHMWPE fillers, including carbon nanofibers, carbon nanotube, and graphene, the uses of nanocellulose, including CNF in the UHMWPE matrix, is much less and yet to be widely studied. This is probably due to the high melt viscosity of UHMWPE, attributed to molecular weights ranging from 3 to 6 million g/mol [ 20 , 21 ], which make dispersing hydrophilic CNF and avoiding filler agglomeration to be very challenging. However, the use of high-speed processing can improve the filler dispersion in the matrix through the generation of high-shear force and high shearing rate [ 22 ], notwithstanding associated thermal degradation and/or chain scission of the polymer [ 23 ].…”