Wear performance of ultrahigh molecular weight polyethylene/quartz composites.

Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, People's Republic of China.
Biomaterials (Impact Factor: 8.31). 06/2003; 24(11):1889-96. DOI: 10.1016/S0142-9612(02)00610-5
Source: PubMed

ABSTRACT Ultrahigh molecular weight polyethylene (UHMWPE)/quartz composites were compression molded in the presence of organosiloxane, and then hydrolyzed. The used organosiloxane is vinyl tri-ethyloxyl silane. The gelation, the melting behavior, the crystallinity, the mechanical properties and the wear resistance of UHMWPE/quartz composites were investigated. The results showed that organosiloxane can act as a cross-linking agent for UHMWPE matrix and serve as a coupling agent for improving the bonding between the quartz particles and the UHMWPE matrix. The correlation between the various properties and the morphology of the composites has been discussed. At about 0.5phr organsiloxane while the degree of crystallinity of the composite is at the peak value of 57%, the mechanical properties and the wear resistance of UHMWPE/quartz composites reaches their maximum.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A new patent pending technique is proposed in this study to improve the mechanical and biological performance of ultra high molecular weight polyethylene (UHMWPE), i.e., to uniformly coat nylon onto the UHMWPE fiber (Firouzi et al., 2012). Mechanical tests were performed on neat and new nylon coated UHMWPE fibers to examine the tensile strength and creep resistance of the samples at different temperatures. Cytotoxicity and osteolysis induced by wear debris of the materials were investigated using (MTT) assay, and RT-PCR for tumor necrosis factor alpha (TNFα) and interleukin 6 (IL-6) osteolysis markers. Mechanical test results showed substantial improvement in maximum creep time, maximum breaking force, and toughness values of Nylon 6,6 and Nylon 6,12 coated UHMWPE fibers between average 15% to 60% at 25, 50, and 70 °C. Furthermore, cytotoxicity studies have demonstrated significant improvement in cell viability using the nylon coated UHMWPE over the neat one (72.4% vs 54.8%) for 48 hours and (80.7 vs 5%) for 72 hours (P<0.01). Osteolysis test results have shown that the expression levels of TNFα and IL-6 markers induced by the neat UHMWPE fiber were significantly higher than those induced by the Nylon 6,6 coated UHMWPE (2.5 fold increase for TNFα at 48 hours, and three fold increase for IL-6 at 72 hours (P<0.01)). This study suggests that UHMWPE coated with nylon could be used as a novel material in clinical applications with lower cytotoxicity, less wear debris-induced osteolysis, and superior mechanical properties compared to neat UHMWPE.
    Journal of the Mechanical Behavior of Biomedical Materials 01/2014; 32:198-209. · 2.37 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In the present study, different series of High Density Polyethylene (HDPE)/carbon nano-composites were prepared using melt blending in a co-rotating intermeshing twin screw extruder. The morphological, thermal, rheological, viscoelastic, mechanical, and fracture toughness properties of the nano-composites were analyzed. The microscopic examination of the cryogenically fractured surface found a good distribution of carbon nano-particles in the HDPE matrix. The melting temperature was not significantly affected by the addition of nano-carbon. Whereas, the crystallization percentage was slightly affected by adding carbon nano-particles into the matrix. The complex viscosity increased as the percentage of carbon increased. The Dynamic Mechanical Analysis (DMA) showed that the storage modulus increased with increasing the carbon nano-particles ratio and with increasing the testing frequency. The tensile test results showed that with increasing the carbon nano-particles contents, the Young’s modulus, yield strength of HDPE nano-composite increased while the strain at fracture decreased. Similarly, the fracture toughness and the strain energy release rate decreased proportional to the carbon content.
    Materials & Design - MATER DESIGN. 01/2011; 32(4):1974-1980.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Ultra high molecular weight polyethylene (UHMWPE) was prepared by using MgCl2-supported TiCl4 catalyst in conjunction with triethylaluminium (TEA) cocatalyst. The effects of internal and external donor on polydispersity index (PDI) of UHMWPE were investigated. The catalyst activity with various kinds of internal donor decreased in the following order: none > succinate > phthalate > diether, while the catalyst activity was less influenced by the structure of external donor. The PDI of UHMWPE was examined by using gel permeation chromatography (GPC) analysis and/or rheometry measurements. The PDI obtained by rheometer was matched with the results obtained by GPC within an error of max. 20%. The highest molecular weight and PDI of UHMWPE were obtained by the catalyst of succinate as internal donor. It was also observed that the molecular weight and PDI of UHMWPE were less affected by the introduction of external donor.
    Polymer Bulletin 01/2011; 66(5):627-635. · 1.33 Impact Factor

Full-text (2 Sources)

Available from
May 22, 2014