Chemically Cross‐Linked UHMWPE With Superior Toughness

Abstract

Radiation cross‐linked ultra‐high‐molecular‐weight polyethylenes (UHMWPEs) are clinically used extensively in total joint arthroplasty due to their high wear resistance. Peroxide cross‐linking of UHMWPE has been proposed to achieve this high level of wear resistance by simultaneously consolidating and cross‐linking in the melt state. High temperature melting of uncross‐linked and cross‐linked UHMWPEs have further shown to improve the toughness. Here, we report on the wear and mechanical properties of a peroxide cross‐linked and high‐temperature melted UHMWPE as a function of vitamin E concentration for oxidative stabilization, peroxide concentration for cross‐linking and high temperature melting temperature for toughness improvement. This method, combining consolidation and cross‐linking in one step, presents an opportunity to manufacture highly wear and oxidation‐resistant joint implant‐bearing surfaces with much improved toughness. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2182–2188, 2019

Ultrahigh molecular weight polyethylene with improved crosslink density, oxidation stability, and microbial inhibition by chemical crosslinking and tea polyphenols for total joint replacements

“…Di‐alkyl peroxide is commonly used for crosslinking of UHMWPE in industries, mostly associated with extrusion and molding as a conversion of blended powders into solid products 22,23 . Organic peroxide “P130” (2,5‐Di[tert‐butylperoxyl]‐2,5‐dimethyl‐3‐hexyne) has been used to crosslink UHMWPE for joint application because of its free radical producibility and good biocompatibility 24 . The free radicals formed by the decomposition of P130 initiate hydrogen abstraction of UHMWPE, which forms the crosslinks to bond the adjacent molecular chains 25 .…”

Processability and physico‐mechanical properties of ultrahigh‐molecular‐weight polyethylene using low‐molecular‐weight olefin wax

“…UHMWPE of AsahiKASEI (SunFine™), Japan, UH 900 grade with viscosity average molecular weight of 3.3 Â 10 6 g/mole and density of 0.96 g/cm 3 was procured from Bhilwara Polymers (Rajasthan, India). Polyethylene wax (210P) of viscosity average molecular weight 2000 g/ mole and density 0.94 g/cm 3 was obtained from Mitsui Chemicals India Pvt.…”

“…[2] Wear and mechanical properties of UHMWPE significantly improved by oxidative stabilization through vitamin E concentration, cross-linking by peroxide concentration, and applying high temperature for melting to enhance toughness. [3,4] UHMWPE is produced by heterogeneous Mg-Ti (ligandmetal) catalysts and selected metallocene/postmetallocene complexes (catalyst activator) through proper selection of ligand-metal, catalyst-activator combination. The performance properties such as high mechanical strength and modulus, low density, dielectric property, high-energy absorption, chemical inertness, and solvent resistance offered by UHMWPE, made it a suitable candidate for medical products, protective clothing, transportation, antiballistic products, and sporting goods.…”

Improved oxidation stability and crosslink density of chemically crosslinked ultrahigh molecular weight polyethylene using the antioxidant synergy for artificial joints

“…The peroxide, 2,5-Di[tert-butylperoxyl]2,5-dimethyl-3-hexyne (P130), shows good applicability and biocompatibility in crosslinking UHMWPE bearing. 34,35 It decomposes and forms free radicals at the melting temperature of UHMWPE to bond the adjacent molecular chains. One notable advantage of chemical crosslinking is to allow incorporation of antioxidants at a higher content, 26,36 because chemical crosslinking is less affected by antioxidants than radiation crosslinking.…”