scholarly journals PMMA Bone Cements Modified with Silane-Treated and PMMA-Grafted Hydroxyapatite Nanocrystals: Preparation and Characterization

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3860
Author(s):  
Do Quang Tham ◽  
Mai Duc Huynh ◽  
Nguyen Thi Dieu Linh ◽  
Do Thi Cam Van ◽  
Do Van Cong ◽  
...  
Keyword(s):  
Setting Time ◽  
Maximum Temperature ◽  
Bone Cements ◽  
Gravimetric Analysis ◽  
Pmma Matrix ◽  
Compression Properties ◽  
Pmma Bone Cement ◽  
Hydroxyapatite Nanocrystals ◽  
Microscopy Images ◽  
Thermal Stability Of

In this study, vinyltrimethoxysilane-treated hydroxyapatite (vHAP) and PMMA-grafted HAP (gHAP) were successfully prepared from original HAP (oHAP). Three kinds of HAP (oHAP, vHAP and g HAP) were used as additives for the preparation of three groups of HAP-modified PMMA bone cements (oHAP-BC, vHAP-BC and gHAP-BC). The setting, bending and compression properties of the bone cements were conducted according to ISO 5833:2002. The obtained results showed that the maximum temperature while curing the HAP-modified bone cements (HAP-BCs) decreased from 64.9 to 60.8 °C and the setting time increased from 8.1 to 14.0 min, respectively, with increasing HAP loading from 0 to 15 wt.%. The vHAP-BC and gHAP-BC groups exhibited higher mechanical properties than the required values in ISO 5833. Electron microscopy images showed that the vHAP and gHAP nanoparticles were dispersed better in the polymerized PMMA matrix than the oHAP nanoparticles. FTIR analysis indicated the polar interaction between the PO4 groups of the HAP nanoparticles and the ester groups of the polymerized PMMA matrix. Thermal gravimetric analysis indicated that mixtures of ZrO2/HAPs were not able to significantly improve the thermal stability of the HAP-BCs. DSC diagrams showed that the incorporation of gHAP to PMMA bone cement with loadings lower than 10 wt.% can increase Tg by about 2.4 °C.

scholarly journals Acrylic Bone Cements Modified with Graphene Oxide: Mechanical, Physical, and Antibacterial Properties

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1773 ◽  
Author(s):  
Mayra Eliana Valencia Zapata ◽  
Lina Marcela Ruiz Rojas ◽  
José Herminsul Mina Hernández ◽  
Johannes Delgado-Ospina ◽  
Carlos David Grande Tovar
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Bacterial Infections ◽  
Setting Time ◽  
Antibacterial Properties ◽  
Physical And Mechanical Properties ◽  
Maximum Temperature ◽  
Bone Cements ◽  
Gram Negative ◽  
Total Joint Replacements

Bacterial infections are a common complication after total joint replacements (TJRs), the treatment of which is usually based on the application of antibiotic-loaded cements; however, owing to the increase in antibiotic-resistant microorganisms, the possibility of studying new antibacterial agents in acrylic bone cements (ABCs) is open. In this study, the antibacterial effect of formulations of ABCs loaded with graphene oxide (GO) between 0 and 0.5 wt.% was evaluated against Gram-positive bacteria: Bacillus cereus and Staphylococcus aureus, and Gram-negative ones: Salmonella enterica and Escherichia coli. It was found that the effect of GO was dependent on the concentration and type of bacteria: GO loadings ≥0.2 wt.% presented total inhibition of Gram-negative bacteria, while GO loadings ≥0.3 wt.% was necessary to achieve the same effect with Gram-positives bacteria. Additionally, the evaluation of some physical and mechanical properties showed that the presence of GO in cement formulations increased wettability by 17%, reduced maximum temperature during polymerization by 19%, increased setting time by 40%, and increased compressive and flexural mechanical properties by up to 17%, all of which are desirable behaviors in ABCs. The formulation of ABC loading with 0.3 wt.% GO showed great potential for use as a bone cement with antibacterial properties.

scholarly journals Optimization of Mechanical and Setting Properties in Acrylic Bone Cements Added with Graphene Oxide

2021 ◽  
Vol 11 (11) ◽  
pp. 5185
Author(s):  
Lina Marcela Ruiz Rojas ◽  
Mayra Eliana Valencia Zapata ◽  
Marisol Gordillo Suarez ◽  
Rigoberto Advincula ◽  
Carlos David Grande-Tovar ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Solid Phase ◽  
Clinical Performance ◽  
Setting Time ◽  
Maximum Temperature ◽  
Bone Cements ◽  
Methyl Methacrylate Polymerization ◽  
Randomized Experimental Design ◽  
First Time

The extended use of acrylic bone cements (ABC) in orthopedics presents some disadvantages related to the generation of high temperatures during methyl methacrylate polymerization, thermal tissue necrosis, and low mechanical properties. Both weaknesses cause an increase in costs for the health system and a decrease in the patient’s quality of life due to the prosthesis’s loosening. Materials such as graphene oxide (GO) have a reinforcing effect on ABC’s mechanical and setting properties. This article shows for the first time the interactions present between the factors sonication time and GO percentage in the liquid phase, together with the percentage of benzoyl peroxide (BPO) in the solid phase, on the mechanical and setting properties established for cements in the ISO 5833-02 standard. Optimization of the factors using a completely randomized experimental design with a factorial structure resulted in selecting nine combinations that presented an increase in compression, flexion, and the setting time and decreased the maximum temperature reached during the polymerization. All of these characteristics are desirable for improving the clinical performance of cement. Those containing 0.3 wt.% of GO were highlighted from the selected formulations because all the possible combinations of the studied factors generate desirable properties for the ABC.

scholarly journals Development of Nervilia fordii Extract-Loaded Electrospun PVA/PVP Nanocomposite for Antioxidant Packaging

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1728
Author(s):  
Peng Wen ◽  
Teng-Gen Hu ◽  
Yan Wen ◽  
Ke-Er Li ◽  
Wei-Peng Qiu ◽  
...  
Keyword(s):  
Food Packaging ◽  
Thermo Gravimetric Analysis ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Poly Vinyl Alcohol ◽  
Total Phenolic ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Phenolic And Flavonoid ◽  
Thermal Stability Of

An ethyl acetate extract from of Nervilia fordii (NFE) with considerable suppression activity on lipid peroxidation (LPO) was first obtained with total phenolic and flavonoid contents and anti-LPO activity (IC50) of 86.67 ± 2.5 mg GAE/g sample, 334.56 ± 4.7 mg RE/g extract and 0.307 mg/mL, respectively. In order to improve its stability and expand its application in antioxidant packaging, the nano-encapsulation of NFE within poly(vinyl alcohol) (PVA) and polyvinyl(pyrrolidone) (PVP) bio-composite film was then successfully developed using electrospinning. SEM analysis revealed that the NFE-loaded fibers exhibited similar morphology to the neat PVA/PVP fibers with a bead-free and smooth morphology. The encapsulation efficiency of NFE was higher than 90% and the encapsulated NFE still retained its antioxidant capacity. Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) analysis confirmed the successful encapsulation of NFE into fibers and their compatibility, and the thermal stability of which was also improved due to the intermolecular interaction demonstrated by thermo gravimetric analysis (TGA). The ability to preserve the fish oil’s oxidation and extend its shelf-life was also demonstrated, suggesting the obtained PVA/PVP/NFE fiber mat has the potential as a promising antioxidant food packaging material.

Synthesis and investigation of thermal properties of PMMA-maleimide-functionalized reduced graphene oxide nanocomposites

2018 ◽  
Vol 33 (1) ◽  
pp. 85-96
Author(s):  
Thangamani Rajkumar ◽  
Nagamuthu Muthupandiyan ◽  
Chinnaswamy Thangavel Vijayakumar
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Chemical Interaction ◽  
Weight Percent ◽  
Bulk Polymerization ◽  
Pmma Matrix ◽  
Uniform Dispersion ◽  
Reduced Graphene ◽  
Thermal Stability Of

Reduced graphene oxide (RGEO) and N-[4-(chlorocarbonyl)phenyl]maleimide-functionalized reduced graphene oxide (MFRGEO) were used as nanofillers for polymethyl methacrylate (PMMA) matrix nanocomposites to enhance thermal stability. Methyl methacrylate containing nanofiller of four different weight percent (0.2, 0.4, 0.6, and 0.8) was polymerized using ultrasonic radiation-assisted bulk polymerization. The Fourier-transform infrared spectra showed the absence of chemical interaction between the filler and the matrix phase. Morphology of nanocomposites studied using scanning electron microscope confirmed the assistance aided by ultrasonication in the uniform dispersion of nanofiller in the PMMA matrix. Thermogravimetric (TG) study revealed the presence of MFRGEO enhanced the thermal stability of PMMA by shifting the entire degradation to higher temperature. The thermal stability of PMMA nanocomposite was improved by as much as 40°C at just 0.8 wt% loading of MFRGEO. Differential TG study also supported the role of maleimide functionalization on RGEO in the enhancement of thermal stability of PMMA by means of retarding the degradation rate of unsaturated chain ends in the PMMA matrix. Unlike MFRGEO, RGEO failed to enhance the thermal stability of PMMA.

The effect on the fatigue strength of bone cement of adding sodium fluoride

2001 ◽  
Vol 215 (2) ◽  
pp. 251-253 ◽  
Author(s):  
C Minari ◽  
M Baleanil ◽  
L Cristofolini ◽  
F Baruffaldi
Keyword(s):  
Fatigue Strength ◽  
Bone Cement ◽  
Sodium Fluoride ◽  
Biomedical Applications ◽  
Cement Mantle ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Bone Cements ◽  
The Novel ◽  
Pmma Bone Cement

New bone cements that include several additives are currently being investigated and tested. One such additive is sodium fluoride (NaF), which promotes bone formation, facilitating implant integration and success. The influence of NaF on the fatigue performance of the cement as used in biomedical applications was tested in this paper. In fact fatigue failure of the cement mantle is a major factor limiting the longevity of a cemented implant. An experimental bone cement with added NaF (12wt%) was investigated. The fatigue strength of the novel bone cement was evaluated in comparison with the cement without additives; fatigue tests were conducted according to current standards. The load levels were arranged based on a validated, statistically based optimization algorithm. The curve of stress against number of load cycles and the endurance limit were obtained and compared for both formulations. The results showed that the addition of NaF (12 wt %) to polymethylmethacrylate (PMMA) bone cement does not affect the fatigue resistance of the material. Sodium fluoride can safely be added to the bone cement without altering the fatigue performance of the PMMA bone cement.

scholarly journals Mechanical Failure of Artificial Joint Materials: Wear and Fatigue

2000 ◽  
Author(s):  
L. D. Timmie Topoleski
Keyword(s):  
Cyclic Loading ◽  
Bone Cement ◽  
Fatigue Failure ◽  
Relative Motion ◽  
Wear Mechanisms ◽  
Bone Cements ◽  
Artificial Joint ◽  
Artificial Joints ◽  
Cocrmo Alloy ◽  
Pmma Bone Cement

Abstract Total artificial joint replacements are one of the most effective treatments for arthritis. Artificial joints are used to replace damaged cartilage and act as low-friction articulating materials in joints. During normal human walking, some of the materials used for artificial knee and hip replacements are subjected to both sliding articulation (relative motion) and cyclic loading. A common example is the CoCrMo alloy femoral surface of an artificial knee that articulates against an ultra-high-molecular-weight-polyethylene (UHMWPE) component. Other materials do not experience relative motion (at least not intentionally) and are subjected to only cyclic loading. An example is the poly(methyl methacrylate) or PMMA bone cement used to fix components of artificial joints into bones. In the case of articulating materials, both surfaces are susceptible to wear, from both second-body and third body (in the presence of abrasive particles) mechanisms. Wear of the UHMWPE has received considerable attention recently, since the polymer wear is far more obvious than the metal wear. The Biomaterials field is developing an understanding of the wear mechanisms and how to enhance the wear resistance of UHMWPE. The wear of the metal components has not received as much attention, yet materials wear as a couple; both surfaces play a role in the overall wear. In the UMBC Laboratory for Implantable Materials, we are investigating the mechanisms of CoCrMo alloy wear, and the effect of worn metal components on the wear of UHMWPE. Understanding the wear mechanisms of metal components may help to extend the life of artificial joints by allowing new articulating material combinations and joint designs. For non-articulating materials, fatigue failure is a primary concern. Fatigue of metal components is relatively rare. In the distal portion of an artificial hip, the metal hip stem is fixed into the bone by a layer of PMMA bone cement. The PMMA bone cement is far weaker and less resistant to fracture and fatigue than either the bone or the metal, and thus may be considered the mechanical “weak link” in cemented total joints. We are investigating the fatigue properties of PMMA bone cements, and studying the mechanisms of fatigue crack initiation. If we can determine how fatigue cracks start in bone cement, we may be able to develop, for example, new surgical procedures (e.g., bone preparation) that will reduce the likelihood of fatigue failure. New formulations of bone cement have been developed for both joint fixation, and also for bone repair or replacement. Understanding the failure mechanisms of bone cements may enable safe and effective new uses for new bone cements, and extend the lives of cemented artificial joints.

scholarly journals Spectroscopic Insight into Tetrahedrally Distorted Square Planar Copper(II) Complex: XRD/HSA, Physicochemical, DFT, and Thermal Investigations

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1179
Author(s):  
Ahmed Boshaala ◽  
Abrahem F. Abrahem ◽  
Abdulla Ali Almughery ◽  
Nabil Al-Zaqri ◽  
Abdelkader Zarrouk ◽  
...  
Keyword(s):  
Density Functional ◽  
Gravimetric Analysis ◽  
Perfect Agreement ◽  
Functional Theory ◽  
Square Planar ◽  
The Density Functional Theory ◽  
Thermal Investigations ◽  
Ligand Coordination ◽  
Thermal Stability Of ◽  
Cis Isomer

The reaction of bidentate N-S-thione-Schiff base, (E)-benzyl 2-(1-(4-chlorophenyl)- ethylidene)hydrazinecarbodithioate, with Cu(NO3)2·3H2O produced a cis-Cu(II) complex. The molecular structure was confirmed and characterized by CHN-EA, FAB-MS, IR, and UV-Vis analyses. The XRD supported cis-isomer of the bis anionic bidentate N (azomethine) and S (thiol) ligand coordination mode in tetrahedrally distorted square planar, rarely reported in the literature. The results of the XRD-bond lengths were in perfect agreement with the density functional theory (DFT) calculation. DFT-calculated angles around the Cu(II) center displayed slightly less distortion around the metal center from those of XRD. Additionally, the thermal stability of the complex was evaluated via thermal gravimetric analysis (TGA). Two-dimensional fingerprint (2D-FP), Hirshfeld surface analysis (HSA), and molecular electrostatic potential (MEP) support the XRD-packing results with the existence of the H⸱⸱⸱Cl and CH⸱⸱⸱π bonds as the main interactions in the crystal lattice of the desired complex.

The pH-Dependent Properties of the Biphasic Calcium Phosphate for Bone Cements

2014 ◽  
Vol 21 ◽  
pp. 3-16 ◽  
Author(s):  
Nuan La Ong Srakaew ◽  
Sirirat Tubsungnoen Rattanachan
Keyword(s):  
Compressive Strength ◽  
Liquid Phase ◽  
Calcium Phosphate ◽  
Phase Analysis ◽  
Calcium Phosphate Cement ◽  
Biphasic Calcium Phosphate ◽  
Setting Time ◽  
Bone Cements ◽  
Apatite Formation ◽  
Apatite Cement

Self-setting calcium phosphate cement (CPC) has been used in bone repair and substitution due to their excellent biocompatibility, bioactive as well as simplicity of preparation and use. The inherent brittleness and slow degradation are the major disadvantages for the use of calcium phosphate cements. To improve the degradation for the traditional CPC, the apatite cement formula incorporated with β-tricalcium phosphate (β-TCP) with varying concentration were studied and the effect of the pH value of liquid phase on the properties of this new calcium phosphate cement formula was evaluated. The apatite cements containing β-TCP for 10 and 40 wt.% were mixed into the aqueous solution with different pH values and then aging in absolute humidity at 37°C for 7 days. The setting time and phase analysis of the biphasic calcium phosphate were determined as compared to the apatite cement. For proper medical application, the compressive strength, the phase analysis and the degradation of the CPC samples at pH 7.0 and 7.4 were evaluated after soaking in the simulated body fluid (SBF) at 37°C for 7 days. The results indicated that the properties of the samples such as the setting time, the compressive strength related to the phase analysis of the set cements. The high degradation of the CPC was found in the cement with increasing β-TCP addition due to the phase after setting. Apatite formation with oriented plate-like morphology was also found to be denser on the surface of the biphasic bone cements after soaking in SBF for 7 days. The obtained results indicated that the cement containing β-TCP mixed with the liquid phase at pH 7.4 could be considered as a highly biodegradable and bioactive bone cement, as compared to the traditional CPC.

Preparation of Poly(aniline-co-phenol) and Study Its Properties and Its Polymerization Kinetics Using Two Methods: UV-Vis and HPLC

2021 ◽  
Vol 43 (5) ◽  
pp. 505-505
Author(s):  
Juhaina Alghdir and Ahmad Falah Juhaina Alghdir and Ahmad Falah
Keyword(s):  
Transition Temperature ◽  
Reaction Order ◽  
Sem Analysis ◽  
304 Stainless Steel ◽  
Melting Transition ◽  
Gravimetric Analysis ◽  
Zero Order Reaction ◽  
Kinetics Of ◽  
Thermal Stability Of ◽  
Poly Aniline

The co-polymerization of polyaniline is one of the most important methods used to improve the electrical activity and thermal stability of polyaniline. Previously, electrochemical co-polymerization of phenol and aniline was performed on 304 stainless steel anodes. In this study, we present the co-polymerization of aniline and phenol chemically at laboratory temperature in an acidic medium with ammonium pyrosulfate as an oxidant. The Scanning Electron Microscopy (SEM) analysis of poly(aniline-co-phenol) sample shows a rough (non-smooth) surface with crystalline particles with microscopic diameters. We characterized the prepared polymer with DSC, DTA, and thermos gravimetric analysis (TGA). We found that the thermal decomposition of poly(aniline-co-phenol) was on six steps. The glass transition temperature of the co-polymer (Tg) was found at 863.89 and#176;C and the melting transition temperature was observed at 877.80 and#176;C. We studied the kinetics of Poly(aniline-co-phenol) using two methods: UV-Vis, HPLC. Then we determined the reaction order. It was found that the reaction was the zero-order reaction (n=0) in both previous two methods.

Thermotropic Copolyesters Based on Polyethylene Terephthalate and 4-Hydroxybenzoic Acid for High Modulus Fibers

2021 ◽  
Vol 887 ◽  
pp. 3-9
Author(s):  
T.R. Deberdeev ◽  
A.I. Akhmetshina ◽  
S.V. Grishin
Keyword(s):  
Dimethyl Ester ◽  
Hydroxybenzoic Acid ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
Polymer Backbone ◽  
Molecular Compounds ◽  
Anisotropic Phase ◽  
Thermal Stability Of ◽  
Thermotropic Copolyesters

The copolyesters derived from dimethyl ester of terephthalic acid, ethylene glycol, and 4-hydroxybenzoic acid (HBA) have been synthesized via catalytically promoted polycondensation omitting the acetylation step. FTIR spectroscopy results have evidenced an insertion of HBA along a polymer backbone. Of note, thermal gravimetric analysis has shown that the HBA moieties substantially improved the thermal stability of polyesters. As found by differential scanning calorimetry and polarizing microscopy, the copolyesters are capable of forming an anisotropic phase in a temperature range of 150-170 °C. Additionally, the free surface energy of the samples was determined to evaluate the compatibility of thermotropic copolyesters with other high-molecular compounds.

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