Ultra-high molecular weight polyethylene (UHMWPE) has been broadly utilized in hip and knee artificial implant due to its low friction coefficient, high wear resistance and good biocompatibility. However, some disadvantage properties such as low young's modulus and low load bearing, anti-fatigue capacity limit application areas and wear debris of UHMWPE components cause implant failure. For this reason, reduced graphene oxide (RGO) filler was produced by green synthesis with vitamin C and the influences of RGO filler content on the tribological performance under distilled water lubrication condition were investigated and had been correlated with microstructure. RGO filled UHMWPE biocomposites were fabricated by firstly liquid phase ultrasonic mixing and then hot press molding. The characterization and experiment results revealed that the wear behavior of UHMWPE/RGO biocomposites were not only affected by the lubricant and binder properties of RGO, but also restricted by the content of RGO filler. The RGO filled UHMWPE biocomposites exhibited a lower wear rate and friction coefficient in comparison to the unfilled UHMWPE. The biocomposite with 0.7 wt% of RGO showed good interfacial bonding strength and excellent wear resistance. Furthermore, fatigue wear tracks reduced significantly on the same biocomposite surface. High crystallite size and microhardness value of UHMWPE/RGO-0.7 biocomposite was caused destroy the tribofilm formed on the Al 2 O 3 counterface.

Reduced graphene oxide (RGOC) filler that was green synthesized by vitamin C had been included in the ultrahigh molecular weight polyethylene (UHMWPE) matrix to produce biocomposite possessing improved properties especially against wear. The biocomposites filled with different loading (0.1, 0.3, 1.0, and 2.0 wt%) of RGOC was produced by a method of liquid phase ultrasonic mixing and then hot press molding. The structural analysis results of biocomposites showed that RGOC well‐dispersed in polymer matrix and confirmed that there was interaction between the RGOC‐UHMWPE. The biocomposite containing 2.0 wt% RGOC (UHMWPE/RGOC‐2) gave the maximum microhardness and the value increased by 22. 5% compared with unfilled polymer. At the same RGOC content, the biocomposite had the highest thermal stability with residue content at 2.42%. The wear and friction behavior of biocomposites were carried out in a reciprocating friction testing machine under distilled water lubricating conditions. The UHMWPE/RGOC‐2 biocomposite had the lowest friction coefficient value (0.034) and the wear rate of the biocomposite decreased by 44%, compared with that of unfilled UHMWPE. Furthermore, fatigue wear tracks were significantly reduced. This study suggests the use of this composite that had excellent tribological behavior as biomaterial instead of UHMWPE.

No abstract

Ultra yüksek moleküler ağırlıklı polietilen (UHMWPE), biyo-uyumluluğu ve mükemmel özellikleri nedeniyle kalça ve diz protezleri için en uygun malzemedir. Bu çalışmada, düşük yoğunluğa ve yağlayıcı özelliğe sahip olan grafen dolgu maddesi olarak kullanılmış ve kompozitin performansını güçlendirmek için UHMWPE matrisine ilave edilmiştir. Saf UHMWPE ve ağırlıkça % 0,5 indirgenmiş grafen oksit (CRGO) dolgulu kompozitin (CRGO / UHMWPE) aşınma davranışları kuru ve sulu ortamlarda incelenmiştir. UHMWPE ve CRGO sıvı faz ultrasonik dispersiyon ile karıştırıldıktan sonra kompozit örnekleri sıcak pres kalıplama ile üretilmiştir. FTIR analiz sonuçları, dolgu maddesi ile polimer matrisi arasında etkileşim olduğunu, XRD analizi UHMWPE' nin kristali yapısında meydana gelen değişimi, SEM-EDS elementel haritalama analizi sonuçları ise oksijenin polimer matrikste homojen bir şekilde dağıldığını göstermiştir. Kompozit örneğinin sürtünme katsayısı ve aşınma hızı değerleri CRGO ilavesiyle hem kuru hem de sulu ortamda azalmıştır. Çünkü hem grafen hem de saf suyun yağlayıcı özelliği, kompozit örneğinin sürtünme ve aşınma davranışını önemli ölçüde etkilemiştir. Kompozit numune için kuru kayma koşullarında plastik deformasyon ve yorulma aşınması baskınken, sulu ortamda adhezif aşınma izleri gözlenmiştir.