Influence of the model environment on the structure and properties of composite materials with doxorubicin based on polyurethanes with isocyanurate fragments

2021 ◽  
Vol 43 (1) ◽  
pp. 54-63
Author(s):  
G.A. Kozlova ◽  
◽  
R.A. Rozhnova ◽  
L.Yu. Nechaeva ◽  
N.A. Galatenko ◽  
...  
Keyword(s):  
Composite Materials ◽  
Relative Elongation ◽  
Mechanical Tests ◽  
Structure And Properties ◽  
Weakly Bound ◽  
Entire Study ◽  
Biological Tests ◽  
Polyurethane Composites ◽  
Model Environment

The influence of the BM 199 model environment on the structure and properties of composite materials with Doxorubicin based on polyurethanes (PU) with isocyanurate branching nodes, in which the content of 2,4,6-triisocyanate(trishexamethylene)isocyanurate (HDT-90) was 0.25.0 , 5, 0.75 mol, and the content of the drug Doxorubicin is 0.5% wt. It was found that the obtained materials exhibit the ability to biodegradation in vitro. In a study by IR spectroscopy of changes in the structure of polyurethane composites with Doxorubicin under the influence of BM 199, it was found that, in the series of polyurethanes, with an increase in the residence time in the model environment, a decrease in the number of weakly bound (νNH 3516 cm-1) and strongly bound bonds of NH groups ( νNH 3515 cm-1), which can occur both due to the biodegradation of the polymer base, and as a result of the release of Doxorubicin. For all the samples under study, during their stay in the biological medium, there is a decrease in the strength at break by 1.5-1.9 times and an increase in the relative elongation by 1.1-1.4 times. According to the data of physical-mechanical tests for all studied materials, the process of biodegradation in vitro is accompanied by an increase in elasticity during the entire study period. According to the results of the study of the dynamics release of Doxorubicin, it was found that from polyurethane composites with isocyanurate branching nodes containing 0.75 mol of HDT-90 in the structure, Doxorubicin is released within 21 days in an amount of 17.6%, which is 4 times more than for samples compositions with 0.5 mole of HDT-90, from which 4.4% of Doxorubicin is released, which may be related to the packing density of the macrochain of the polymer base. Composite materials based on polyurethanes with izocyanurate fragments and Doxorubicin can be proponated for medical and biological tests as material for stem implantation of tissue with prolong medicinal action.

scholarly journals The study of the structure and properties of nanostructured biodegradable thermoplastic composite

2018 ◽  
Vol 80 (2) ◽  
pp. 302-306 ◽  
Author(s):  
N. A. Shcherbina ◽  
V. A. Taganova ◽  
E. V. Bychkova ◽  
S. Ya. Pichkidze
Keyword(s):  
Composite Material ◽  
Lactic Acid ◽  
Composite Materials ◽  
Relative Elongation ◽  
Thermoplastic Composite ◽  
Polymer Materials ◽  
Structure And Properties ◽  
Natural Mineral ◽  
Nanostructured Composite ◽  
Mineral Fillers

Increased requirements for polymer materials and the expansion of their application fields create the prerequisites for the creation of new composite materials. The most promising matrix for the biocomposite material is 2-hydroxypropionic (lactic) acid, the unique capabilities of which are manifested as a result of modification by inorganic mineral fillers of nanometric size. The combination of such properties as Biodegradability and biocompatibility is particularly valuable in this polymer. Nanostructured composite materials, consisting of polylactic acid and mineral fillers, acquire a significant improvement in properties compared to the properties of a pure polymer. Biodegradable films containing a layered natural mineral from the class of metasilicates were obtained by the method of irrigation of molding solutions. Trichloromethane was used as a solvent for the preparation of molding solution. The structure and properties of a nanostructured thermoplastic composite are studied. It is shown that the filler is evenly distributed in the polymer structure, affects the size of the crystal formations, the size of the crystallites increases. The introduction of a nanostructuring mineral into a biopolymer increases the thermal stability of the composite, which is due to the high resistance to high temperatures of the initial micro-reinforcing mineral filler, which does not decompose to a temperature of 1000-1100 0C. The influence of layered natural mineral from the class of metasilicates on the deformation and strength properties of biocompositeis established: the strength is maintained and the relative elongation at material rupture is slightly reduced. The ability to biodegradation and very low toxicity allow the use of nanostructured composite material based on 2-hydroxypropionic (lactic) acid in biomedical, pharmaceutical, environmental and industrial fields. The development of biodegradable composite material will solve the current domestic problems of polymers for medical purposes.

The Mechanical Properties of Organic Modified Epoxy Resin

2020 ◽  
Vol 43 (3) ◽  
pp. 10-14
Author(s):  
Georgel MIHU ◽  
Claudia Veronica UNGUREANU ◽  
Vasile BRIA ◽  
Marina BUNEA ◽  
Rodica CHIHAI PEȚU ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Epoxy Resins ◽  
Mechanical Tests ◽  
Organic Modification ◽  
Three Point Bending ◽  
Modified Epoxy

Epoxy resins have been presenting a lot of scientific and technical interests and organic modified epoxy resins have recently receiving a great deal of attention. For obtaining the composite materials with good mechanical proprieties, a large variety of organic modification agents were used. For this study gluten and gelatin had been used as modifying agents thinking that their dispersion inside the polymer could increase the polymer biocompatibility. Equal amounts of the proteins were milled together and the obtained compound was used to form 1 to 5% weight ratios organic agents modified epoxy materials. To highlight the effect of these proteins in epoxy matrix mechanical tests as three-point bending and compression were performed.

Study of the Composite Materials Optimal Structure Containing a Hollow Aluminum and Silica Microsphere Dependence on Humidity

2020 ◽  
Vol 12 ◽  
Author(s):  
Alexandra Atyaksheva ◽  
Yermek Sarsikeyev ◽  
Anastasia Atyaksheva ◽  
Olga Galtseva ◽  
Alexander Rogachev
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Strength Function ◽  
Theory And Practice ◽  
Optimal Structure ◽  
Optimal Size ◽  
Structure And Properties ◽  
Power Functions ◽  
Silica Microsphere ◽  
Heat Engineering

Aims:: The main goals of this research are exploration of energy-efficient building materials when replacing natural materials with industrial waste and development of the theory and practice of obtaining light and ultra-light gravel materials based on mineral binders and waste dump ash and slag mixtures of hydraulic removal. Background.: Experimental data on the conditions of formation of gravel materials containing hollow aluminum and silica microsphere with opportunity of receipt of optimum structure and properties depending on humidity with the using of various binders are presented in this article. This article dwells on the scientific study of opportunity physical-mechanical properties of composite materials optimization are considered. Objective.: Composite material contains hollow aluminum and silica microsphere. Method.: The study is based on the application of the method of separation of power and heat engineering functions. The method is based on the use of the factor structure optimality, which takes into account the primary and secondary stress fields of the structural gravel material. This indicates the possibility of obtaining gravel material with the most uniform distribution of nano - and microparticles in the gravel material and the formation of stable matrices with minimization of stress concentrations. Experiments show that the thickness of the cement shell, which performs power functions, is directly related to the size of the raw granules. At the same time, the thickness of the cement crust, regardless of the type of binder, with increasing moisture content has a higher rate of formation for granules of larger diameter. Results.: The conditions for the formation of gravel composite materials containing a hollow aluminosilicate microsphere are studied. The optimal structure and properties of the gravel composite material were obtained. The dependence of the strength function on humidity and the type of binder has been investigated. The optimal size and shape of binary form of gravel material containing a hollow aluminosilicate microsphere with a minimum thickness of a cement shell and a maximum strength function was obtained. Conclusion.: Received structure allows to separate power and heat engineering functions in material and to minimize the content of the excited environment centers.

Mechanical characterization of a woven multi-layered hyperelastic composite laminate under uniaxial loading

2021 ◽  
pp. 002199832110115
Author(s):  
Shaikbepari Mohmmed Khajamoinuddin ◽  
Aritra Chatterjee ◽  
MR Bhat ◽  
Dineshkumar Harursampath ◽  
Namrata Gundiah
Keyword(s):  
Composite Materials ◽  
Energy Function ◽  
Strain Energy ◽  
Strain Energy Function ◽  
Mechanical Tests ◽  
Stress Strain ◽  
Aerospace Applications ◽  
Envelope Material ◽  
The Individual ◽  
High Dielectric

We characterize the material properties of a woven, multi-layered, hyperelastic composite that is useful as an envelope material for high-altitude stratospheric airships and in the design of other large structures. The composite was fabricated by sandwiching a polyaramid Nomex® core, with good tensile strength, between polyimide Kapton® films with high dielectric constant, and cured with epoxy using a vacuum bagging technique. Uniaxial mechanical tests were used to stretch the individual materials and the composite to failure in the longitudinal and transverse directions respectively. The experimental data for Kapton® were fit to a five-parameter Yeoh form of nonlinear, hyperelastic and isotropic constitutive model. Image analysis of the Nomex® sheets, obtained using scanning electron microscopy, demonstrate two families of symmetrically oriented fibers at 69.3°± 7.4° and 129°± 5.3°. Stress-strain results for Nomex® were fit to a nonlinear and orthotropic Holzapfel-Gasser-Ogden (HGO) hyperelastic model with two fiber families. We used a linear decomposition of the strain energy function for the composite, based on the individual strain energy functions for Kapton® and Nomex®, obtained using experimental results. A rule of mixtures approach, using volume fractions of individual constituents present in the composite during specimen fabrication, was used to formulate the strain energy function for the composite. Model results for the composite were in good agreement with experimental stress-strain data. Constitutive properties for woven composite materials, combining nonlinear elastic properties within a composite materials framework, are required in the design of laminated pretensioned structures for civil engineering and in aerospace applications.

Structure and Properties of Novel Superhard Nanocrystalline/Amorphous Composite Materials

1995 ◽  
Vol 400 ◽  
Author(s):  
S. Vepřek ◽  
M. Haussmann ◽  
S. Reiprich
Keyword(s):  
Elastic Modulus ◽  
Composite Materials ◽  
Transition Metal ◽  
Theoretical Concept ◽  
Structure And Properties ◽  
Superhard Materials ◽  
Transition Metal Nitride ◽  
Upper Limit ◽  
Amorphous Si ◽  
Matrix Hardness

AbstractWe have developed a theoretical concept for the design of novel superhard materials and verified it experimentally on several systems nc-MenN/a-Si3N4 (nc-MenN is a nanocrystalline transition metal nitride imbedded in a thin amorphous Si3N4 matrix). Hardness in excess of 5000 kg/mm2 (about 50 GPa) and elastic modulus of ≥550 GPa have been achieved [1-3]. Here we address the questions of the universality of the concept for the design of a variety of nc/a systems and the upper limit of the hardness which may be achieved.

New manufacturing process to develop antibacterial dyed polyethylene terephthalate sutures using plasma functionalization and chitosan immobilization

2021 ◽  
pp. 152808372110505
Author(s):  
Nesrine Bhouri ◽  
Faten Debbabi ◽  
Abderrahmen Merghni ◽  
Esther Rohleder ◽  
Boris Mahltig ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polyethylene Terephthalate ◽  
Manufacturing Process ◽  
Antibacterial Effect ◽  
Inhibition Zone ◽  
The United States ◽  
Mechanical Tests ◽  
Inflammatory Reactions ◽  
Plasma Functionalization

The main purpose of this paper is to develop a new manufacturing process leading to have antibacterial dyed non-absorbable braided polyethylene terephthalate (PET) sutures using biocompatible and non-toxic products. This manufacturing process allows better visibility of sutures in the surgical field and reduces the risk of infections and inflammatory reactions without affecting the mechanical properties while meeting the United States Pharmacopeia (USP) requirements. Plasma functionalization, acrylic acid (AA) grafting, and bioactive chitosan (CH) coating were used before the dyeing process with a biocompatible non-toxic acid dye, approved by the Food and Drug Administration (FDA). The influence of experimental parameters on the suture properties and the K/S values of the dyed sutures are investigated. Infrared spectroscopy confirms the presence of new bonds to immobilize chitosan on the surface of the suture. Mechanical tests confirm that the mechanical properties of sutures have not been affected. The in vitro antibacterial effect of dyed PET sutures showed an inhibition zone of 11 mm against S. aureus, 4 mm against P. aeruginosa, and 1 mm against E. coli. This study reveals that the new finishing process of sutures is a promising method to achieve an antibacterial effect with a uniform shade and smooth surfaces.

Investigation of the Staging of Damage Accumulation in Polymer Composite Materials during Bending and Tensile Tests

2021 ◽  
Vol 887 ◽  
pp. 116-122
Author(s):  
A.A. Bryansky ◽  
O.V. Bashkov ◽  
Daria P. Malysheva ◽  
Denis B. Solovev
Keyword(s):  
Acoustic Emission ◽  
Composite Materials ◽  
Polymer Composite ◽  
Loading Rate ◽  
Tensile Tests ◽  
Mechanical Tests ◽  
Rate Effect ◽  
Polymer Composite Materials ◽  
Static Tension ◽  
Point Bend

The paper presents the results of the study of registered acoustic emission (AE) parameters during static deformation and damaging of polymer composite materials (PCM). Mechanical tests were done by a static tension and a static three-point bend, accompanied by an acoustic emission method. The assessment of the loading rate effect on defects formation processes was done by additional static tension test at rate equal half of recommended by the standard and static three-point bend test at rate ten times lower than that calculated by the standard. Clustering by frequency components of the recorded AE signals with a self-organizing Kohonen map was performed. The characteristics of the types of PCM structure damage by the centroids of the obtained clusters are given. Based on the clusters accumulation during mechanical tests, the stages of damage formation for static tension and static three-point bend, the loading rate effect on the process of damage formation are described.

DEVELOPMENT AND RESEARCH OF POLYURETHANE FOAM COMPOSITE MATERIALS WITH LYSOZYME

2021 ◽  
Vol 43 (3) ◽  
pp. 204-213
Author(s):  
T.V. VISLOHUZOVA ◽  
◽  
R.A. ROZHNOVA ◽  
N.A. GALATENKO ◽  
◽  
...  
Keyword(s):  
Glass Transition ◽  
Composite Materials ◽  
Polyurethane Foam ◽  
Single Phase ◽  
Mechanical Tests ◽  
Polyurethane Foams ◽  
Scanning Calorimetry ◽  
Heating Capacity ◽  
Foam Composite ◽  
Treatment Of Wounds

The article is devoted to the development and research of the structure and properties of polyurethane foam (PUF) composite materials with the antibacterial enzyme lysozyme. A series of PUF composite materials with lysozyme of various concentrations (1, 3 and 5 wt %) were obtained. It is established that the immobilization of lysozyme occurs due to intermolecular hydrogen bonds by the method of IR spectroscopy. According to the results of physical-mechanical tests the adhesive strength of polyurethane foam compositions with lysozyme is in the range of 0,82–1,16 MPa. The introduction of lysozyme into the composition of polyurethane foams and an increase its amount causes a decrease in the values of adhesion strength by 18,1–29,3 %. According to differential scanning calorimetry the tested systems are single-phase with a glass transition temperature in the range of -49,20 to -49,86 °C. The introduction of lysozyme into the composition causes an increase heating capacity at the glass transition, which can be associated with a decrease of the packing density of macrochains resulting in an increase in free volume, which leads to an increase molecular mobility. According to the results of the analysis of transmission optical microscopy micrographs the studied PUF have a microporous structure, which depends on the content of filler in their composition. It was found that the presence of lysozyme in the composition of composite materials leads to a decrease in the percentage of porosity, an increase in the number of pores with a diameter of up to 300 μm, which is 76,7–82,4 % (while for PUF – 69,5 %) and the absence of pores with a diameter larger than 990 μm. Thermogravimetric characteristics indicate the heat resistance of the synthesized PUF to a temperature of 179,95 °C, which allows dry sterilization of samples without changing their characteristics. PUF composite materials with lysozyme are promising materials that can be used in medical practice as polymer compositions for the treatment of wounds and burns.

scholarly journals Compatibility, Stability, and Efficacy of Vancomycin Combined With Gentamicin or Ethanol in Sodium Citrate as a Catheter Lock Solution

2017 ◽  
Vol 52 (10) ◽  
pp. 685-690
Author(s):  
Yangjie Wei ◽  
Joshua WonJoon Yang ◽  
Sai HS. Boddu ◽  
Rose Jung ◽  
Mariann D. Churchwell
Keyword(s):  
Chemical Stability ◽  
Sodium Citrate ◽  
Chronically Ill ◽  
Storage Conditions ◽  
Entire Study ◽  
Indwelling Catheters ◽  
Source Of Infection ◽  
Lock Solution ◽  
All Solutions

Background: Indwelling catheters deliver lifesaving medical treatments for many chronically ill patients but are frequently a source of infection. Treatment may include an antimicrobial agent(s) and anticoagulant solution dwelling within the catheter. In vitro determinations of solution compatibility and stability are necessary prior to use in patients. Objective: The aim of this study was to determine the physical compatibility, chemical stability, and antimicrobial activity of vancomycin (5 or 10 mg/mL) with gentamicin (1 mg/mL) or 40% ethanol in 4% sodium citrate lock solution over 72 hours. Methods: All solutions were prepared per manufacturer’s instructions. Samples were studied under 4 conditions: (1) 25°C with light, (2) 25°C without light, (3) 37°C with light, and (4) 37°C without light. Physical compatibility and chemical stability were assessed at 0, 24, 48, and 72 hours. Antimicrobial susceptibility testing was conducted at 0 and 72 hours. All studies were carried out in triplicate. Results: All solution combinations under each condition remained patent from baseline to 48 hours. One solution combination of vancomycin (5 mg/mL) and ethanol (40% v/v) in 4% sodium citrate revealed a slight turbidity at 72 hours. Clarity and pH remained stable in all other solutions during the entire study period. Chemical compatibility and antibiotic activity ranged from 95% to 105% and 95% to 106% of initial baseline values, respectively, for all solutions under 4 storage conditions. Conclusions: All antibiotic-anticoagulant lock solutions were found to be physically, chemically, and microbiologically stable during the 72-hour study period except vancomycin (5 mg/mL) and ethanol (40% v/v) in 4% sodium citrate solution which showed slight turbidity at 72 hours.

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