Search results for: MISCIBLE POLYMER BLENDS
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Preparation and characterization of rigid polyurethane-polyglycerolnanocomposite foams
PublicationThis work reports on the preparation of polyurethane-polyisocyanurate (PUR-PIR) foams containing different polyglycerols and layered silicate nanoclays. The rigid polyurethane foams were obtained in a laboratory scale, in a single step method, from a two-component system with a NCO to OH groups ratio equal to two. The reaction mixture consisted of the proper amounts of a commercial oligoetherpolyol, polyglycerol, catalysts, water,...
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Microwave radiation in the synthesis of urethane prepolymers
PublicationThis paper describes the use of microwave radiation in the synthesis of urethane prepolymers in bulk (without solvent). The prepolymers were synthesized using 1,6-hexamethylene diisocyanate (HDI) and poly (ε-caprolactone) diol (PCL) at a molar ratio of 4:1. The reaction was carried out without a catalyst in the reactor with a conventional heating system (oil bath) or in the microwave reactor (MW Reactor NOVA 09) at temperatures...
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Thermoplastic polyurethanes derived from petrochemical or renewable resources: A comprehensive review
PublicationThermoplastic polyurethanes (TPUs) materials are obtained by the reaction of polyol (ether-, ester-, and carbonate-based diols with average molecular weight in the range from 1,000 to 3,000 g/mol) with aliphatic or aromatic diisocyanates. Synthesized materials consist of the hard and soft segments which are separated in different level. All mechanical and thermal properties of TPUs depend on the chemical structure of used monomers,...
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A comparative study on selective properties of Kraft lignin–natural rubber composites containing different plasticizers
PublicationEffect of plasticizer type on the kraft lignin–nat- ural rubber composite microstructure and selected proper- ties was determined. The composites were prepared with addition of a commonly used naphthenic oil plasticizer to study the decomposition product of polyurethane (glyc- erolysate) and its characteristics. Kraft lignin powder was incorporated into the natural rubber matrix in amounts of 10 and 40 parts per 100 parts of natural...
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Elastic polyurethane foams containing graphene nanoplatelets
PublicationElastic polyurethane foams were produced from two-component polyurethane systems (SPECFLEX NE 113 izocyjanian/NR 816 poliol system—SPC and Elastic MBMarket company system POLYOL ET MB 500/ISO ET MB 800—ET) by using a one-step method. The foams were a graphene nanoplatelets (GNP) in the amount ranging from 1 to 2 wt.%. The effect of the nanofiller on polyurethane matrix was determined by analyzing the chemical structure, static...
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Mechanical and thermal analysis of injection molded poly(methyl methacrylate) modified with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) fire retarder
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Clickable polysaccharides for biomedical applications: A comprehensive review
PublicationRecent advances in materials science and engineering highlight the importance of designing sophisticated biomaterials with well-defined architectures and tunable properties for emerging biomedical applications. Click chemistry, a powerful method allowing specific and controllable bioorthogonal reactions, has revolutionized our ability to make complex molecular structures with a high level of specificity, selectivity, and yield...
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Degradation of polyurethanes in sea water
PublicationOceniono degradowalność różnych poliuretanów w wodzie morskiej Bałtyku. Porównano te dane z wynikami stopnia degradacji poliuretanów w wodzie morskiej z dodatkiem azydku sosowego. Ocenę stopnia degradacji przeprowadzano na podstawie pomiarów zmian masy, właściwości mechanicznych i morfologii przed i po procesie degradacji. Wykazano, że różna podatność na degradację poliuretanów w wodzie morskiej związana jest z ich odmiennym stopniem...
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Submicron inorganic particles as an additional filler in hybrid epoxy matrix composites reinforced with glass fibres
PublicationIn this study, the effect of selected submicron metal oxide (zinc oxide, titanium oxide) or non-metal oxide (silicon dioxide) particles on mechanical and thermo-mechanical properties of epoxy/glass composites was investigated. The applied epoxy resin was a diglycidyl ether of bisphenol-A cured with triethylenetetramine. As a reinforcement twill weave E-glass fabric was used. Hybrid composites (contained particulate and fibrous...
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Enhancement of PUR/PIR foam thermal stability after addition of Zostera marina biomass component investigated via thermal analysis and isoconversional kinetics
PublicationIn the present work, a thorough thermogravimetric (TG) analysis of bio-based polyurethane–polyisocyanurate (PUR–PIR) foams in both nitrogen and oxygen atmosphere is performed. A sustainable element of the foam is a biopolyol obtained via acid-catalyzed liquefaction of Zostera marina and Enteromorpha Algae biomass. Based on isoconversional analysis and apparent activation energies, several conclusions are obtained. In contradiction...
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Effect of molar ratio [NCO]/[OH] groups during prepolymer chains extending step on the morphology and selected mechanical properties of final bio‐based thermoplastic poly(ether‐urethane) materials
PublicationThe main aim of this work was to investigate the effect of [NCO]/[OH] molar ratio used during the prepolymer chain extending step (with bio‐based diols) on the chemical structure, and thermomechanical and mechanical properties of thermoplastic poly(ether‐urethane)s. Thermoplastic poly(ether‐urethane)s were obtained from bio‐based polyol (polytrimethylene ether glycol), bio‐based glycol (1,4‐butanediol or 1,3‐propanediol), and 4,4'diphenylmethane...
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Fully bio-based poly(propylene succinate) synthesis and investigation of thermal degradation kinetics with released gases analysis
PublicationOne of the most important information about polyesters is their thermal stability and phase transition tem- peratures. These characteristics give information about the promising behavior of the polyester during proces- sing. In this work, linear bio-based polyester polyols were prepared with the use of succinic acid and 1.3- propanediol (both with natural origin). As a polycondensation catalyst was used tetraisopropyl orthotitanate...
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Thermoplastic polyurethanes with glycolysate intermediates from polyurethane waste recycling
PublicationThe polyol is a major component in polyurethane formulations and therefore introducing to the formulation recycled polyol (obtained during decomposition process) allows decreasing the usage of pure petrochemical components. In this work, thermoplastic polyurethanes were prepared using various mixtures of a petrochemical macrodiol poly(ethylene-butylene adipate)diol (PEBA) and a recycled glycolysate intermediate, called glycolysate...
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The influence of amorphous macrodiol, diisocyanate type and l-ascorbic acid modifier on chemical structure, morphology and degradation behavior of polyurethanes for tissue scaffolds fabrication
PublicationStudies described in this work were related to the bulk synthesis and characterization of polyurethanes (PURs) obtained with the use of cyclic 4,4′-methylene bis(cyclohexyl isocyanate) (HMDI) or linear 1,6-hexamethylene diisocyanate (HDI), amorphous α,ω-dihydroxy(ethylene-butylene adipate) macrodiol (PEBA), 1,4-butandiol (BDO) chain extender and dibutyltin dilaurate (DBTDL) catalyst. Obtained PURs were modified with l-ascorbic...
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Effect of bio-based components on the chemical structure, thermal stability and mechanical properties of green thermoplastic polyurethane elastomers
PublicationIt seems to be obvious that conditions changes during polyols synthesis have impact on the polyols properties. Even the chemical formula is the same or similar, physicochemical properties and also molecular weight of polyols might be different and are significant in term of future polyurethanes properties and processing. In this work, fully bio-based poly(propylene succinate)s synthesized at different temperature conditions were...
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Structure and properties comparison of poly(ether-urethane)s based on nonpetrochemical and petrochemical polyols obtained by solvent free two-step method
PublicationThe application of thermoplastic polyurethanes (TPU) is becoming more and more extensive, and the decreasing of used petrochemical monomers and reduction of energy for the polymerization and processing processes is getting increasingly important. In this paper, we confirmed the positive influence of high bio-based monomers contents (by replacing petrochemical polyol and glycol by bio-based counterparts) on processing and properties...
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A comprehensive evaluation of flexible FDM/FFF 3D printing filament as a potential material in medical application
PublicationThe use of FDM/FFF in 3D printing for medical sciences is becoming common. This is due to the high availability and decent price of both 3D printers and filaments useful for FDM/FFF. Currently, researchers' attention is focused mainly on the study of medical filaments based on PLA, PCL or their modifications. This contributes to insufficient diversity of medical-grade filaments on the market. Moreover, due to the lack of specified...
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Assessment of the devulcanization process of EPDM waste from roofing systems by combined thermomechanical/microwave procedures
PublicationEthylene-propylene-diene rubber (EPDM) is a elastomer widely used in common industrial applications. EPDM can be shaped into sheets and employed as isolating material for roofing systems. In this study, scraps of EPDM from commercial, industrial and residential roofing systems were treated by combined thermo-mechanical and microwave devulcanization processes including peroxide of benzoyl (BPO). The devulcanized EPDM (Dev-EPDM)...
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Synthesis and characterisation of polyurethane elastomers with semi-products obtained from polyurethane recycling
PublicationIn this work polyurethane elastomers were synthesised by using different mixtures of a petrochemical and glycerolysate polyols and 4,4-diphenylmethane diisocyanate (MDI). Glycerolysate polyol was produced from polyurethane foam decomposition using crude glycerine as a decomposition agent. The structure and thermal properties of obtained semi-product were similar to the polyol used in the synthesis of original foam. Glycerolysate...
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Evaluation of structural change during fast transformation process of cross-linked NR into liquid NR by light pyrolysis
PublicationThe presence of cross-linked networks in rubber creates a tremendous problem for recycling and reusing of waste rubber. Fast transformation of cross-linked natural rubber (NR) into liquid natural rubber was carried out by light pyrolysis in temperature range from 240 to 300 °C in variable time (in range: 1–30 min). The transformation efficiency was evaluated by measuring the sol fraction and the cross-link density of the gel fraction....
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Integration of protein tethering in a rapid and label-free SERS screening platform for drugs of abuse
PublicationSurface enhanced Raman spectroscopy (SERS) has emerged as a promising technique for the rapid and ultrasensitive detection of molecular species such as drugs of abuse in biofluids. Yet, it remains a significant challenge to create a viable screening tool for multiple drug classes, owing to the lack of affinity of certain species for the SERS substrate and to the matrix interference in complex media. Here we report a protein tethering...
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Green Approaches in Rubber Recycling Technologies: Present Status and Future Perspective
PublicationAs a consequence of massive production and consumption of rubbers, rubber blends, and rubber composites for myriad applications, elastomeric products have enormously accumulated and become an environmental threat. The disposal and burning of rubber wastes have been banned because of environmental and economic reasons. By contrast, a great deal of attention has been directed toward strategies enabling recycling and reuse of rubbers....
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Electrochemical synthesis and characterization of nanocomposites based on poly(3,4-ethylenedioxythiophene) and functionalized carbon nanotubes
PublicationThis work is focused on new composite materials consisting of poly(3,4-ethylenedioxythiophene) (pEDOT) and functionalized multi-walled carbon nanotubes synthesized electrochemically. Three types of composites were synthesized: the first one containing carbon nanotubes with carboxyl groups (covalent functionalization), the second one containing oxidized carbon nanotubes ox-MWCNTs (with different oxygen-rich polar groups) (covalent...
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Composite 2D Material-Based Pervaporation Membranes for Liquid Separation: A Review
PublicationToday, chemistry and nanotechnology cover molecular separations in liquid and gas states by aiding in the design of new nano-sized materials. In this regard, the synthesis and application of two-dimensional (2D) nanomaterials are current fields of research in which structurally defined 2D materials are being used in membrane separation either in self-standing membranes or composites with polymer phases. For instance, pervaporation...
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Analiza trwałości zmęczeniowej asfaltów drogowych i modyfikowanych z wykorzystaniem testu liniowego zwiększania amplitudy / Analysis of the fatigue life of neat and modified bitumens using linear amplitude sweep test
PublicationThe paper presents an evaluation of the fatigue resistance of selected Polish bituminous binders: neat bitumen 50/70, polymer modified bitumen PMB 45/80-55 and polymer highly modified bitumen PMB 45/80-80. The linear amplitude sweep (LAS) test, which is a new bitumen performance grading test developed in the USA, and was used to assess the fatigue life of the bitumens. Highly modified bitumen 45/80-80 showed 10-20 times higher...
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Structural Changes and Their Implications in Foamed Flexible Polyurethane Composites Filled with Rapeseed Oil-Treated Ground Tire Rubber
PublicationThe utilization of post-consumer car tires is an essential issue from an ecological andeconomic point of view. One of the simplest and the least harmful methods is their material recyclingresulting in ground tire rubber (GTR), which can be further applied as fillers for polymer-basedcomposites. Nevertheless, insufficient interfacial interactions implicate the necessity of GTR modi-fication before introduction into polymer matrices....
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Recycling of Waste Rubber by the Manufacturing of Foamed Polyurethane-Based Composites—Current State and Perspectives
PublicationWorn car tires are disruptive waste, and the issue of their management is crucial for the natural environment. In many countries, the primary method of end-of-life tires utilization is energy recovery. However, more effective and beneficial for the environment is material recycling. Using them for the production of polymer-rubber composites seems to be an auspicious direction of research. Incorporation of ground tire rubber into...
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Quantum dots in gas sensing a review
PublicationAir pollution becomes an increasing problem in the recent years. There is a need to develop more sensitive gas sensors. Much effort has been performed to develop different types of gas sensors, such as electrochemical sensors or polymer sensors. One of the most promising approaches to improve sensors performance is the application of the nanostructures as sensing materials. State of the art of quantum...
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Numerical model of human head phantom to ensure dosimetry of dose components for boron neutron capture therapy
PublicationExtremely important aspects of the boron neutron capture therapy are, first of all, administering to the patient a boron compound that selectively reaches the neoplastic cells, and in the second step, the verification of the irradiation process. This paper focuses on the latter aspect, which is the detailed dosimetry of the processes occurring after the reaction of thermal neutrons with the boron-10 isotope. The results of computer...
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Thermomechanical and Fire Properties of Polyethylene-Composite-Filled Ammonium Polyphosphate and Inorganic Fillers: An Evaluation of Their Modification Efficiency
PublicationThe development of new polymer compositions characterized by a reduced environmental impact while lowering the price for applications in large-scale production requires the search for solutions based on the reduction in the polymer content in composites’ structure, as well as the use of fillers from sustainable sources. The study aimed to comprehensively evaluate introducing low-cost inorganic fillers, such as copper slag (CS),...
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INVESTIGATION OF ACIDIC SOLUTIONS BY POTENTIOMETRIC TASTE SENSOR WITH ALL SOLID STATE ELECTRODES
PublicationPotentiometric taste sensors with electrodes containing lipophilic compound / polymer membranes were already used to distinguish commercial liquid products. In this paper a new potentiometric taste sensor consisting of six All Solid State Electrodes (ASSEs) has been presented. Each of the membrane contains a selected lipophilic compound. The set-up consists of a reference electrode and six ASSEs. The inner layer made of a conducting...
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Improving performance of large thrust bearings through modeling and experimentation
PublicationLarge thrust bearings are highly loaded machine elements and their failures cause serious losses. Start ups and stoppages of the bearing under load are specially critical regimes of operation. Load carrying capacity depends on the profile of the oil gap. In transient states this profile is also changing. In the design of large thrust bearings minimizing thermo-elastic deformations is an important goal, which can be accomplished...
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Influence of selected submicron inorganic particles on mechanical and thermo-mechanical properties of unsaturated polyester/glass composites
PublicationIn this paper, the influence of different submicron-scaled particles (zinc oxide, titanium dioxide, or silica) on mechanical and thermo-mechanical properties of unsaturated polyester matrix composites reinforced with glass fabric was investigated. Surface morphology of obtained composites was also examined. At first inorganic particles were mechanically dispersed into unsaturated polyester resin system as per the calculated weight...
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Experimental comparison of hydrodynamic thrust bearings with different pad surface materials
PublicationBabbitt is the material most frequently used as the pad surface material for hydrodynamic bearings operating at usual operating conditions. It shows many advantages important for safe bearing operation, as for example: low friction coefficient, corrosion resistance, fair mechanical properties and outstanding conformability. On the other hand, it is not free from disadvantages, such as limited fatigue strength or limited resistance...
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Bitumen-Based Poroelastic Pavements: Successful Improvements and Remaining Issues
PublicationThis article presents the development process of designing and testing poroelastic pavement based on highly polymer-modified bitumen. Poroelastic wearing course was composed of mineral and rubber aggregate mixed with highly polymer-modified bitumen, in contrast to previous trials, during which polyurethane resins were mainly used as binder, which led to several serious technological problems concerning difficult production, insufficient...
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The effect of PEDOT morphology on hexavalent chromium reduction over 2D TiO2/PEDOT photocatalyst under UV–vis light
PublicationThe present study represents an approach to apply organic-inorganic hybrid materials for photocatalytic removal of heavy metals from the aqueous environment. The photocatalytic activity of the semiconductor modified with the conjugated polymer may depends on the conjugated polymer type, its amount and morphology. Therefore, in the present study the effect of poly (3, 4-ethylenedioxythiophene) (PEDOT) morphology on adsorption and photoreduction...
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Synthesis, Structure, and Spectroscopic Properties of Calcium Thiophenecarboxylate Polymers. Structural Comparison with Analogous Lead Complexes
PublicationThree novel calcium coordination polymers [Ca(2tpCOO)2(2mpa)(H2O)]n (1), [Ca(3tpCOO)2(2mpa)(H2O)]n (2), and {[Ca(3tpacCOO)2(H2O)2]⋅⋅⋅H2O}n (3) (2tpCOO− or 3tpCOO− – thiophene-2- or thiophene-3-carboxylate, 3tpacCOO− – thiophene-3-acetate, 2mpa – 2-methylpropanal), were synthesised using a self-assembly method. The obtained polymers were characterised using SC-XRD, FTIR, UV-Vis DRS, thermogravimetric and luminescence analyses. The...
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Real-time monitoring of the emission of volatile organic compounds from polylactide 3D printing filaments
PublicationEstablishing the emission profile of volatile organic compounds generated during fused deposition modeling 3D printing using polymer filaments is important in terms of both understanding the processes taking place during thermal degradation of thermoplastics, and assessing the user's exposure to potentially harmful volatiles. However, obtaining detailed, real-time qualitative and quantitative results poses a challenge. In this...
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Peculiarities associated with testing polyetheretherketone (PEEK) in a model rolling contact
PublicationPolyetheretherketone (PEEK) was investigated using a modified version of the four-ball tester in which the upper forth ball was replaced by a cone in such a way that kinematics of the four-ball configuration were fully preserved. Rotation of the cone enforced orbiting and rolling of the ceramic balls around the polymer cup. The results produced some unexpected peculiarities in the wear of ceramic balls which, in principle, should...
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GTR/NBR/Silica Composites Performance Properties as a Function of Curing System: Sulfur versus Peroxides
PublicationIn this work, conventional sulfur and two types of organic peroxides (dicumyl peroxide (DCP) and di-(2-tert-butyl-peroxyisopropyl)-benzene (BIB)) curing systems were used to investigate the possibility for tailoring of the performance properties of GTR/NBR blends reinforced with a variable content of highly dispersive silica (0–30 phr). The curing characteristics, static mechanical and acoustical properties, swelling behavior,...
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Thermal utilization of meat-and-bone meal using the rotary kiln pyrolyzer and the fluidized bed boiler – The performance of pilot-scale installation
PublicationThermal utilization of meat-and-bone meal (MBM) is subject to stringent regulations that are meant to provide elimination of any potential pathogens. Incineration as well as other possible routes for thermal conversion of MBM are still at the research state. The universal technology was developed that allows to combust various types of waste organic materials, including animal waste, municipal solid waste and sludge, mixed at any...
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Polybrominated diphenyl ether (PBDE) concentrations in dust from various indoor environments in Gdańsk, Poland: Prediction of concentrations in indoor air and assessment of exposure of adults
PublicationMonitoring of polybrominated diphenyl ethers (PBDEs) in indoor environments involves the determination of their concentrations in air, airborne particles, and settled dust. Each of these is a source of human exposure to PBDEs. In this study, we attempted to model PBDEs concentrations in various typical indoor environments on the basis of real PBDEs measurements in dust collected from them. The analytical procedure for determining...
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Experimental investigations on concrete beams reinforced with CFRP lamellas
PublicationPaper presents experimental investigation made on two concrete beams reinforced with internal Carbon Fibre Reinforced Polymer (CFRP) lamellas (i.e. strips, bands). The reinforcement geometrical arrangement was similar as in normal concrete beams reinforced with steel bars and stirrups. The beams were destroyed by the shear forces, as intended. Obtained load-carrying capacities were lower as expected: below 40% of a calculated value....
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Degradation of Polycaptolactone Modified with TPS or CaCO3 in Biotic/Abiotic Sewater
PublicationThe polymer degradation process in two types of water sourced from the Baltic Sea was investigated. Polycaprolactone modified with thermoplastic starch(PCL/TPS>85%) or calcium carbonate (60% PCL/40% CaCO3)and PCL alone were incubated for 28 weeks in sea water with and without microrganisms. The experimental results indicated that in each of the experiments degradation occured. The process was more effective in sea water with microorganisms.Modification...
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Study of the influence of thermal factors on the welding process of polyethylene gas pipelines,
PublicationA one-dimensional calculation scheme is proposed with the help of which it is possible to determine and set the technological parameters with the accuracy to be realized in production conditions: the temperature of the heating element and the heating time, which allows maximum mechanization of the technological operations of polyethylene gas pipelines welding. The numerical value of the coefficient of temperature for polyethylene...
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Thermosensitive composite based on agarose and chitosan saturated with carbon dioxide. Preliminary study of requirements for production of new CSAG bioink.
PublicationThis study introduces a method for producing printable, thermosensitive bioink formulated from agarose (AG) and carbon dioxide-saturated chitosan (CS) hydrogels. The research identified medium molecular weight chitosan as optimal for bioink production, with a preferred chitosan hydrogel content of 40–60 %. Rheological analysis reveals the bioink's pseudoplastic behavior and a sol-gel phase transition between 27.0 and 31.5 °C. The...
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The Impact of Ground Tire Rubber Oxidation with H2O2 and KMnO4 on the Structure and Performance of Flexible Polyurethane/Ground Tire Rubber Composite Foams
PublicationThe use of waste tires is a very critical issue, considering their environmental and economic implications. One of the simplest and the least harmful methods is conversion of tires into ground tire rubber (GTR), which can be introduced into different polymer matrices as a filler. However, these applications often require proper modifications to provide compatibility with the polymer matrix. In this study, we examined the impact...
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Electrode materials for electrochemical capacitors based on poly(3,4-ethylenedioxythiophene) and functionalized multi-walled carbon nanotubes characterized in aqueous and aprotic electrolytes
PublicationWithin this work, we report a facile one-stage synthesis of nanocomposites based on functionalized carbon nanotubes (CNTs) and electroactive polymer poly(3,4-ethylenedioxythiophene). Three different composites are investigated as potential electrode materials for the electrochemical capacitors. Two of the composites contain carbon nanotubes (ox-CNTs), functionalized by acid oxidation process (65% HNO3, 120 °C). The third composite...
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Reclaimed rubber in-situ grafted with soybean oil as a novel green reactive plasticizer in SBR/silica compounds
PublicationPolymer recycling and biodegradable polymeric materials are two major routes towards the sustainable development of polymer materials which contributes to the management of waste. In this regard, an eco-friendly approach is presented wherein high reclaiming degree of ground tire rubber (GTR) was achieved by low-temperature oxidation under swollen action of soybean oil. In-situ reclaimed GTR with soybean oil was cured into reactive...
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The use of GFRP tubes as load-bearing jackets in concrete-composite columns
PublicationThe paper presents the fields of applications of polymer composites in building structures. The use of composite glass fibre tubes is discussed in more detail. The laboratory methods used to test the mechanical properties of these pipes are presented. An original research program is presented, including six concrete-filled glass fibre tubes. The cylinders and columns made in this way were tested for their axial load capacity. Conclusions...