Modification effects of short carbon fibers on mechanical properties and fretting wear behavior of UHMWPE composites

Radiation crosslinked ultrahigh molecular weight polyethylene (X-UHMWPE) powder was prepared by g-ray irradiation under nitrogen atmosphere with a dose of 50-200 kGy at a dose rate of 7 kGy/h and further annealing in vacuum at 120 8C for 4 h. The crosslinked powder was characterized by FT-IR spectroscopy, gel content, and hot-press molding. Then, X-UHMWPE was added to pristine UHMWPE to prepare a composite with 0-25 wt % filler. The morphology, wear resistance, and tensile property of the composite were investigated. Using X-UHMWPE as a filler could sufficiently improve the wear resistance of the composite. Adding 25 wt % X-UHMWPE (dose: 150 kGy) improved wear resistance by 130% and retained approximately 90% tensile strength and 70% ductility. Wear-resistant and ductile UHMWPE composite may be potentially used for artificial joint replacement and engineering devices. The proposed route is useful in fabricating UHMWPE material with excellent comprehensive performance or functional polymer composite. INTRODUTIONUHMWPE is a polymer with numerous outstanding properties such as chemical inertness, excellent biocompatibility, good mechanical properties, and widely used in medical and engineering applications. Several unsatisfactory mechanical properties of this polymer are its poor creep-resistance and yield strength. Although UHMWPE exhibits better wear resistance than many other polymers, prolonged use of medical devices made from this polymer used as artificial joint produced debris in the human body. 1 This phenomenon shortens the lifetime of the device and induces pain to the patient. 2,3 Therefore, improving the wear resistance of UHMWPE is still urgent for its application as artificial organ and in engineering devices. Physical blending 4 and radiation crosslinking 5 are two useful methods for improving the wear resistance of UHMWPE. 6,7 Many fillers, such as carbon black, carbon fibers, 8,9 carbon nanotubes (CNTs), 7,10 and Al 2 O 3 , have been added to UHMWPE for physical blending to improve the wear resistance of this polymer. 11 However, dispersion compatibility remains a problem in most cases primarily because of the remarkable difference in chemical structure and surface energy. In addition, the chemical and physiological toxicity of the added material are important in vivo. For instance, 0.1 wt % CNTs in polyethylene can reduce the 80% wear of polyethylene, 12 but this supplementation can even induce cancer in vivo. 13 Therefore, these composites have not been used clinically. Polyethylene blends with other types of polyethylene exhibit better compatibility and lower physiological toxicity than blends with other materials. [14][15][16] This blending method can be used to improve the mechanical properties of UHMWPE. 15,17 Radiation crosslinking can obviously alter the chemical and crystal structures of UHMWPE. This process increases the molecular weight and induces the formation of crosslinking networks. These characteristics sufficiently improve the mechanical properties of UHMWPE such as creep resistanc...

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introdutionmentioning

confidence: 99%

See 3 more Smart Citations

More wear‐resistant and ductile UHMWPE composite prepared by the addition of radiation crosslinked UHMWPE powder

Wang

Zhang

et al. 2016

Effects of reinforcements and gamma‐irradiation on wear performance of ultra‐high molecular weight polyethylene as acetabular cup liner in hip‐joint arthroplasty: A review

Nayak

Balani

2021

Improving the wear resistance of ultra‐high molecular weight polyethylene (UHMWPE), the gold standard polymer for acetabular component in hip joint arthroplasty, is the most important challenge in joint arthroplasty. The possible ways that have been approached to this challenge are by: (i) engineering multi‐phase that is, both carbonaceous and noncarbonaceous fillers‐based polyethylene composites, which unite the inherent attributes of each element available in the system. The wear rate of carbonaceous composite is nearly 50% lower (5.11–6.69 × 10−5 mm3/Nm) than that of noncarbonaceous composite (10–12.5 × 10−5 mm3/Nm), thus, recognized as a potential reinforcement, and (ii) coupling gamma‐irradiation, which is a mandated sterilization process, with multi‐phase nanocomposite to understand the free radical‐scavenging effect of fillers and improved interfacial adhesion strength between fillers and matrix. After the exposure of gamma‐rays (50–100 kGy), the free radicals formed by bond breakage in both the reinforcements and the matrix recombine to form covalent/Van der Waals bond in the interface. Thus, dramatical improvement in wear resistance of both types of composites with 2–4 times decreased wear rate is observed compared to that of composites under un‐irradiated condition. However, enhancing the interfacial adhesion between two different phases is a major constraint in the design of UHMWPE composites. Many methods such as functionalization of reinforcements, and irradiation on functionalized UHMWPE composites that can be approached to address this constraint are documented in this review.

Surface modification of UHMWPE fibers with chlorination and polydopamine for enhancing the mechanical properties of composites

Yuan

Zheng

Wu³

et al. 2022

Ultra-high molecular weight polyethylene (UHMWPE) fibers had many excellent mechanical properties, but their applications in composites were limited due to the weak interfacial adhesion between UHMWPE fibers with non-polar methylene and resin matrix. This paper explored an efficient method for the damage-free modification of fibers by chloride grafting followed by polydopamine (PDA) deposition to obtain UHMWPE-Cl-PDA fiber while maintaining the excellent mechanical properties of the fiber. The chemical components of surface treated fibers were observed by XPS and FTIR-ATR, and the results proved that the fiber surface has been successfully chlorinated and then coated with PDA layer. The surface morphologies of fibers measured by SEM showed the rough surface of UHMWPE-Cl-PDA fibers was beneficed to anchor the resin matrix. The different mechanical properties of composites were studied, such as interfacial shear strength (IFSS), impact strength, flexural strength and modulus, especially the IFSS between UHMWPE-Cl-PDA and epoxy matrix and the impact strength of UHMWPE-Cl-PDA composite were increased by 29.1% and 53.8%, respectively, compared with UHMWPE fibers deposited by PDA.