Optimizing tribological, tensile & in-vitro biofunctional properties of UHMWPE based nanocomposites with simultaneous incorporation of graphene nanoplatelets (GNP) & hydroxyapatite (HAp) via a facile approach for biomedical applications
“…The mechanical properties of the samples can be explained based on the representative stress-strain curve in Figure 2 . Neat-UHMWPE exhibited a tough and ductile behavior, which was in agreement with published reports on UHMWPE characteristics [ 42 , 43 , 44 , 45 ]. An identical profile was observed on EM-UHMWPE/0 indicated that subjecting UHMWPE to ethanol at room temperature could less likely affect the UHMWPE polymer structure evident from minimal changes in mechanical properties and similar hardening or cold drawing behavior of the samples in uniaxial tension.…”
The major hurdle in melt-processing of ultra-high molecular weight polyethylene (UHMWPE) nanocomposite lies on the high melt viscosity of the UHMWPE, which may contribute to poor dispersion and distribution of the nanofiller. In this study, UHMWPE/cellulose nanofiber (UHMWPE/CNF) bionanocomposites were prepared by two different blending methods: (i) melt blending at 150 °C in a triple screw kneading extruder, and (ii) non-melt blending by ethanol mixing at room temperature. Results showed that melt-processing of UHMWPE without CNF (MB-UHMWPE/0) exhibited an increment in yield strength and Young’s modulus by 15% and 25%, respectively, compared to the Neat-UHMWPE. Tensile strength was however reduced by almost half. Ethanol mixed sample without CNF (EM-UHMWPE/0) on the other hand showed slight decrement in all mechanical properties tested. At 0.5% CNF inclusion, the mechanical properties of melt-blended bionanocomposites (MB-UHMWPE/0.5) were improved as compared to Neat-UHMWPE. It was also found that the yield strength, elongation at break, Young’s modulus, toughness and crystallinity of MB-UHMWPE/0.5 were higher by 28%, 61%, 47%, 45% and 11%, respectively, as compared to the ethanol mixing sample (EM-UHMWPE/0.5). Despite the reduction in tensile strength of MB-UHMWPE/0.5, the value i.e., 28.4 ± 1.0 MPa surpassed the minimum requirement of standard specification for fabricated UHMWPE in surgical implant application. Overall, melt-blending processing is more suitable for the preparation of UHMWPE/CNF bionanocomposites as exhibited by their characteristics presented herein. A better mechanical interlocking between UHMWPE and CNF at high temperature mixing with kneading was evident through FE-SEM observation, explains the higher mechanical properties of MB-UHMWPE/0.5 as compared to EM-UHMWPE/0.5.
“…The mechanical properties of the samples can be explained based on the representative stress-strain curve in Figure 2 . Neat-UHMWPE exhibited a tough and ductile behavior, which was in agreement with published reports on UHMWPE characteristics [ 42 , 43 , 44 , 45 ]. An identical profile was observed on EM-UHMWPE/0 indicated that subjecting UHMWPE to ethanol at room temperature could less likely affect the UHMWPE polymer structure evident from minimal changes in mechanical properties and similar hardening or cold drawing behavior of the samples in uniaxial tension.…”
The major hurdle in melt-processing of ultra-high molecular weight polyethylene (UHMWPE) nanocomposite lies on the high melt viscosity of the UHMWPE, which may contribute to poor dispersion and distribution of the nanofiller. In this study, UHMWPE/cellulose nanofiber (UHMWPE/CNF) bionanocomposites were prepared by two different blending methods: (i) melt blending at 150 °C in a triple screw kneading extruder, and (ii) non-melt blending by ethanol mixing at room temperature. Results showed that melt-processing of UHMWPE without CNF (MB-UHMWPE/0) exhibited an increment in yield strength and Young’s modulus by 15% and 25%, respectively, compared to the Neat-UHMWPE. Tensile strength was however reduced by almost half. Ethanol mixed sample without CNF (EM-UHMWPE/0) on the other hand showed slight decrement in all mechanical properties tested. At 0.5% CNF inclusion, the mechanical properties of melt-blended bionanocomposites (MB-UHMWPE/0.5) were improved as compared to Neat-UHMWPE. It was also found that the yield strength, elongation at break, Young’s modulus, toughness and crystallinity of MB-UHMWPE/0.5 were higher by 28%, 61%, 47%, 45% and 11%, respectively, as compared to the ethanol mixing sample (EM-UHMWPE/0.5). Despite the reduction in tensile strength of MB-UHMWPE/0.5, the value i.e., 28.4 ± 1.0 MPa surpassed the minimum requirement of standard specification for fabricated UHMWPE in surgical implant application. Overall, melt-blending processing is more suitable for the preparation of UHMWPE/CNF bionanocomposites as exhibited by their characteristics presented herein. A better mechanical interlocking between UHMWPE and CNF at high temperature mixing with kneading was evident through FE-SEM observation, explains the higher mechanical properties of MB-UHMWPE/0.5 as compared to EM-UHMWPE/0.5.
“…The effect on melting point was also studied to optimize microwave exposure time during the fabrication of specimens. The X c was measured by equation (31) 53 …”
Section: Resultsmentioning
confidence: 99%
“…As a result, there will be the formation of lamellae and enhanced crystalline structure of composite. 53 The high X c leads to enhanced mechanical behavior of UHMWPE/nano-HA composite. The melting temperature of UHMWPE is also increased with addition of nano-HA as shown in Figure 11(a).Figure 11.Effect of nano-HA inclusions on (a) differential scanning calorimetry curve of UHMWPE/nano-HA (b) DOC of UHMWPE/nano-HA.…”
This work aims to implement an efficient and accurate computational model to predict elastoplastic properties of UHMWPE/nano-HA bio-composite. Mean-field (MF) homogenization and finite element (FE) techniques are implemented to predict the elastoplastic behavior of composite. The predicted results obtained by MF and FE were compared and validated experimentally by fabricating the specimen using microwave-assisted compression molding. The axial and transverse moduli were increased by 49% at a 20% weight fraction of nano-HA. The hardening modulus was also found to be increased by 67%. Further, Degree of crystallinity (Xc) of fabricated composite specimens was determined using differential scanning calorimetry analysis. It was found that the Xc increased 34% with the addition of 20% weight fraction of nano-HA. In vitro, direct contact cytotoxicity and antibacterial test were performed to determine cell adhesion and bacterial behavior of the composite.
“…Mice treated with EA drugs were used as experimental groups, untreated mice were used as a model control group, and those treated with E 2 were used as a positive control group. Successful establishment of an osteoporosis model often requires evaluation of multiple aspects, namely, changes in the bone mass, mechanical properties, bone microstructure, and biochemical metabolic indicators [35,36]. In this experiment, the body weight, uterus index, bone strength, and bone microstructure were selected as observation indicators.…”
Section: Evaluation Of Bone-promoting Properties In Vivomentioning
Osteoporosis is the most common disease involving bone degeneration. As the age of the population increases, the prevalence of the disease is expected to rise. However, current treatment methods do not provide a desirable solution for the restoration of the function of degenerated bones in patients with osteoporosis. This led to emergence of controlled delivery systems to increase drug bioavailability and efficacy specifically at the bone regeneration. In this study, an epimedin A (EA) complex drug system was prepared by solution blending method. In vitro cell-based experiments showed that the EA complex drug could significantly promote the differentiation and proliferation of osteoblasts and increase the alkaline phosphatase activity, calcium nodule formation, and the expression of osteogenesis-related genes and proteins. In vivo experiments further demonstrated that this novel drugs remarkably enhanced bone regeneration. These results suggest that EA may be used for the treatment of osteoporosis.
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