Filtry
wszystkich: 289
wybranych: 270
Wyniki wyszukiwania dla: COMPATIBILIZATION, FILLER MODIFICATION, ISOCYANATES, LIGNOCELLULOSIC FILLERS, WOOD POLYMER COMPOSITES
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Experimental and Numerical Investigation of Tensile and Flexural Behavior of Nanoclay Wood-Plastic Composite
PublikacjaIn this study, the effect of wood powder and nanoclay particle content on composites’ mechanical behavior made with polyethylene matrix has been investigated. The wood flour as a reinforcer made of wood powder was at levels of 30, 40, and 50 wt.%, and additional reinforcement with nanoclay at 0, 1, 3, and 5 wt.%. Furthermore, to make a composite matrix, high-density polyethylene was used at levels of 70, 60, and 50% by weight....
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Effect of the Drying Method of Pine and Beech Wood on Fracture Toughness and Shear Yield Stress
PublikacjaThe modern wood converting processes consists of several stages and material drying belongs to the most influencing future performances of products. The procedure of drying wood is usually realized between subsequent sawing operations, affecting significantly cutting conditions and general properties of material. An alternative methodology for determination of mechanical properties (fracture toughness and shear yield stress) based...
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Interactions of fish gelatin and chitosan in uncrosslinked and crosslinked with EDC films: FT-IR study
PublikacjaFilms based on fish gelatin, chitosan and blend of fish gelatin and chitosan before and after cross-linking with EDC have been characterized by FT-IR spectroscopy. The FT-IR spectrum of fish gelatin film showed the characteristic amide I, amide II and amide III bands, and the FT-IR spectrum of chitosan film confirmed that the polymer was only a partially deacetylated product, and included CH3-C=O and NH2 groups, the latter both...
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Capacitance Enhancement by Incorporation of Functionalised Carbon Nanotubes into Poly(3,4-Ethylenedioxythiophene)/Graphene Oxide Composites
PublikacjaThis paper reports on the role of oxidised carbon nanotubes (oxMWCNTs) present in poly-3,4-ethylenedioxytiophene (PEDOT)/graphene oxide (GOx) composite. The final ternary composites (pEDOT/GOx/oxMWCNTs) are synthesised by an electrodeposition process from the suspension-containing monomer, oxidised carbon nanotubes and graphene oxide. Dissociated functional groups on the surface of graphene oxide play a role of counter-ions for the...
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Recycling of Waste Rubber by Thermo-Mechanical Treatment in a Twin-Screw Extruder
PublikacjaRecycling of waste tires is a significant issue considering both environmental and economic aspects. One of the leading recycling routes is the shredding of tires resulting in the generation of ground tire rubber. This material can be easily introduced into various polymer matrices as a filler, reducing the use of conventionally applied petroleum-based materials. In such cases, it is essential to ensure sufficient interfacial compatibility,...
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The Impact of Hybrid Flame Retardant Compositions on the Performance of Foamed Flexible Polyurethane/Ground Tire Rubber Composites
PublikacjaCurrent sustainability-oriented trends affect polyurethane (PU) materials and stimulate the incorporation of recycled or waste-based materials as fillers. Ground tire rubber (GTR) poses as an auspicious candidate due to the excellent performance of car tires. Despite the benefits related to the mechanical performance, it contributes to the increasing flammability of the resulting composites. Herein, presented work assessed the...
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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
PublikacjaWithin 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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Polymer Modified Bitumen
PublikacjaIn this paper we present the benefits of using polymers as an asphalt modifiers, especially the low molecular weight reactive compounds, which are capable of forming an polymer network with bitumen "in situ" in the process of its modification.
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High-Temperature Tensile Behaviour of GTAW Joints of P92 Steel and Alloy 617 for Two Different Fillers
PublikacjaThis study explores the high-temperature (HT) tensile rupture characteristics of a dissimilar gas-tungsten-arc-welded (GTAW) joint between P92 steel and Alloy 617, fabricated using ER62SB9 and ERNiCrCoMo-1 fillers. The high-temperature tensile tests were performed at elevated temperatures of 550 ◦C and 650 ◦C. An optical microscope (OM) and a field emission scanning electron microscope (FESEM) were utilized to characterize the...
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Novel Approaches of Using of Spirulina Platensis in Natural Rubber Based Composites
PublikacjaThe aim of this work was to investigate the influence of Spirulina (Spirulina platensis) as a natural filler on the curing characterization, morphology and mechanical, thermomechanical and thermal properties of natural rubber (NR) based composites. Spirulina was introduced into NR mixture in amount of 0 phr, 10 phr and 30 phr. The vulcanization process was carried out at the determined process condition by using hydraulic press...
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New-fangled sources of cellulose extraction: comparative study of the effectiveness of Cissus latifolia and Ficus benghalensis cellulose as a filler
PublikacjaRecycled polymers and biopolymers are receiving a great deal of attention these days. If these two can be combined, it will lead to an environment-friendly green material with a great deal of applications. Here the present work is about incorporating bio-based fillers in a recycled polyurethane matrix. Two unusual and extremely novel sources of cellulose have been proposed. The celluloses obtained from Cissus latifolia and Ficus...
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New insights on lithium storage in silicon oxycarbide/carbon composites: Impact of microstructure on electrochemical properties
PublikacjaIn this work, we study the impact of the preceramic precursor vinyltriethoxysilane (VTES) on the electrochemical performance of silicon oxycarbide (SiOC) glass/graphite composites. We apply an innovative approach based on high-power ultrasounds in order to obtain highly homogenous composites with a uniform distribution of small graphitic flakes. This procedure enhances gelation and drying of VTES-based preceramic polymer/graphite...
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Mechanical, thermo-mechanical properties of epoxy/glass composites with submicron particles
PublikacjaIn this research the influence of submicron zinc oxide and silicon dioxide particles on mechanical, thermo-mechanical properties of epoxy matrix composites reinforced with glass fibres was investigated. Composites were fabricated using hand lay-up method. Materials contained 39-41 wt.% of glass fibres. The bending tests, dynamic mechanical analysis and tribological tests were performed on each group of composites and also for...
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Investigation of an elutable N-propylphosphonic acid chitosan derivative composition with a chitosan matrix prepared from carbonic acid solution
PublikacjaPorous chitosan composites using CO2 dissolution procedure and including water soluble N-propylphosphonic chitosan derivative (p-CHI) were obtained and characterized. In contrast to the control material, composites containing modified chitosan distinguished by a rapid moisture absorption and good adhesion to the skin. The FTIR analysis confirmed the presence of propylphosphonic group in the structure of the polymer. The porosity...
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The Effect of Polyurethane Glycolysate on the Structure and Properties of Natural Rubber/Carbon Black Composites
PublikacjaIn this work the use of polyurethane chemical recycling product (i.e. glycolysis of polyurethane waste realized with the mass excess of polymer) as a plasticizer for natural rubber-based composites was proposed. The effect of plasticizer type (napthenic oil and polyurethane foam glycolysate) and amount (2, 4, 6 or 8 parts per 100 parts of natural rubber) on the processing properties of rubber mixtures and chemical structure, swelling,...
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Composite Materials Based on Polymer-Derived SiCN Ceramic and Disordered Hard Carbons as Anodes for Lithium-Ion Batteries
PublikacjaNew composite materials based on polymer-derived SiCN ceramics and hard carbons were studied in view of its application as anodes for lithium-ion batteries. Two kinds of composites were prepared by pyrolysis of the preceramic polysilazane (HTT1800, Clariant) at 1000 °C in Ar atmosphere mixed with hard carbons derived from potato starch (HC_PS) or with a hard carbon precursor, namely potato starch (PS), denoted as HTT/HC_PS and...
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Effect of ground tire rubber on structural, mechanical and thermal properties of flexible polyurethane foams
PublikacjaFlexible polyurethane foams were modified with two kinds of ground tire rubber, untreated and thermo-mechanically reclaimed. A reclamation process was performed in auto-thermal conditions, which reduced the cost of the process and decreased the environmental impact of devulcanization (e.g., emission of gases). The reclamation process was carried out in a continuous manner using a co-rotating twin screw extruder. The foams were...
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Segmented bio-based polyurethane composites containing powdered cellulose obtained from novel bio-based diisocyanate mixtures
PublikacjaA considerable number of research works focus on the positive influence of cellulose on the properties of polymer-based composites and their wide range of application possibilities. The present work is focused on the synthesis of novel bio-based polyurethane (bio-PU) composites filled with powdered cellulose (microcellulose, MC) in an amount of 5 wt.%. Bio-PU composites were synthesized via a non-solvent prepolymer method. First,...
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Structural and physico-mechanical properties of natural rubber/GTR composites devulcanized by microwaves: Influence of GTR source and irradiation time
PublikacjaGround tire rubber from car and truck was modified using microwave irradiation at variable time. The irradiated ground tire rubber was used as filler in composites based on natural rubber. The composites, with high content of ground tire rubber, were prepared using an internal batch mixer and subsequently cross-linked at 160℃. The influence of the ground tire rubber source (car/truck) and irradiation time on structure, physico-mechanical...
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Chemical modifications of graphene and their influence on properties of polyurethane composites: a review
PublikacjaPolyurethane composites are materials of great interest nowadays due to their wide range of available forms and applications in industry. Controlling and achieving unique properties via matrix modifications and addition of various specific nanofillers seems be one of the key elements to success. The purpose of this work is to briefly present some examples of graphene nanoderivatives, their syntheses, properties and influence on...
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A New Microwave Ceramic – Polymer Composite with 0-3 Connectivity
PublikacjaGoal of the present research was to fabricate and study two-phase BiNbO4//PVDF composites with 0-3 connectivity. Such composite consists of there-dimensionally connected polymer matrix loaded with dielectric ceramic particles. In the present case BiNbO4 powder acted as an active phase (dispersed phase) whereas polyvinylidene fluoride (PVDF) acted as a non-active (passive) phase (matrix). BiNbO4//PVDF composites with the volume...
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Adsorption-assisted transport of water vapour in super-hydrophobic membranes filled with multilayer graphene platelets
PublikacjaThe effects of confinement of multilayer graphene platelets in hydrophobic microporous polymeric membranes are here examined. Intermolecular interactions between water vapour molecules and nanocomposite membranes are envisaged to originate assisted transport of water vapour in membrane distillation processes when a suitable filler-polymer ratio is reached. Mass transport coefficients are estimated under different working conditions,...
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Development of polyurethanes for bone repair
PublikacjaThe purpose of this paper is to review recent developments on polyurethanes aimed at the design, synthesis, modifications, and biological properties in the field of bone tissue engineering. Different polyurethane systems are presented and discussed in terms of biodegradation, biocompatibility and bioactivity. A comprehensive discussion is provided of the influence of hard to soft segments ratio, catalysts, stiffness and hydrophilicity...
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Silicon Oxycarbide-Graphite Electrodes for High-Power Energy Storage Devices
PublikacjaHerein we present a study on polymer-derived silicon oxycarbide (SiOC)/graphite composites for a potential application as an electrode in high power energy storage devices, such as Lithium-Ion Capacitor (LIC). The composites were processed using high power ultrasound-assisted sol-gel synthesis followed by pyrolysis. The intensive sonication enhances gelation and drying process, improving the homogenous distribution of the graphitic...
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Interfacially modified LDPE/GTR composites with non-polar elastomers: From microstructure to macro-behavior
PublikacjaThis paper provides some new insights into the mechanism of interaction and modifications in thermoplastic composites based on low density polyethylene (LDPE), ground tire rubber (GTR) and non-polar elastomer. The composites were prepared using a co-rotating twin-screw extruder at variable LDPE/GTR ratio and constant elastomer content. Two types of commercial elastomer were applied: styrene-butadiene-styrene (SBS) block copolymers (Kraton®)...
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Polyurethane/ground tire rubber composite foams based on polyglycerol: processing, mechanical and thermal properties
PublikacjaDuring the synthesis of rigid polyurethane foams, petrochemical polyol was substituted with polyglycerol, the product of thermo-catalytic polycondensation of waste glycerol, resulting from biodiesel production. Two types of ground tire rubbers, untreated and thermo-mechanically reclaimed, were used to obtain ‘‘green’’ polyurethane-polyglycerol composite foams. Samples were prepared by a single-step method for the ratio of NCO/OH...
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Measurements of Thermal Conductivity of LWC Cement Composites Using Simplified Laboratory Scale Method
PublikacjaThe implementation of low-energy construction includes aspects related to technological and material research regarding thermal insulation. New solutions are sought, firstly, to reduce heat losses and, secondly, to improve the environment conditions in isolated rooms. The effective heat resistance of insulating materials is inversely proportional to temperature and humidity. Cement composites filled with lightweight artificial...
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Morphology and properties of recycled polyethylene/ground tyre rubber/thermoplastic poly(ester-urethane) blends
PublikacjaThe growing amount of plastics waste produced every year resulted in development of mechanical and chemical recycling methods of polymers and their blends or composites. From the environmental point of view, the possibility of plastics waste reusing and recycling is desirable. In this study three polymer blends were obtained with using recycled polyethylene (RPE), ground tyre rubber (GTR) and thermoplastic poly(ester-urethane)...
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Permeation and sorption properties of poly(ether-block-amide) membranesfilled by two types of zeolites
PublikacjaThe experimental study of transport properties of mixed matrix membranes (MMMs) based on PEBA-4033 with two types of zeolites is reported. Gas (CO2, O2, N2) and vapor (benzene, toluene, methanol, water) permeation measurements were performed using the differential flow permeameter at temperature of 298.15 K and at atmospheric pressure. Gas/vapor permeation was monitored by measuring the changes of the thermal conductivity of carrier...
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Electrochemical synthesis and characterization of nanocomposites based on poly(3,4-ethylenedioxythiophene) and functionalized carbon nanotubes
PublikacjaThis 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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The impact of natural fibers’ characteristics on mechanical properties of the cement composites
PublikacjaThe paper reviews the properties of cement composites reinforced with short fibres. The effect of natural fibres was investigated: cotton, sisal, jute, ramie, bamboo, and synthetic fibres: polymer and polypropylene. It was noticed that the fibres change the consistency of the mixture up to 15%. In the composite flexural strength tests, a change in strength by +/− 8% was observed, depending on the type of fibres used. The research...
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Closing the loop: Upcycling secondary waste materials into nanoarchitectured carbon composites for the electrochemical degradation of pharmaceuticals
PublikacjaIn this study, we demonstrated the application of electrochemical oxidation as a safer and cleaner technology for minimizing the impact of pharmaceuticals in wastewaters, simultaneously mediated by upcycled secondary waste materials (SWMs)-derived electrodes, to further reduce their environmental impact. The modularity, scalability, ease of operation and reliability make electrochemical oxidation an ideal process for the destruction...
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THE IMPACT OF GROUND TIRE RUBBER TREATMENT ON THE THERMAL CONDUCTIVITY OF FLEXIBLE POLYURETHANE/GROUND TIRE RUBBER COMPOSITES
PublikacjaWaste car tires are burdensome waste, and their utilization is crucial for the natural environment. In many countries, the primary method of their recycling is energy recovery, performed by simple combustion. However, material recycling is much more effective and significantly more beneficial for the natural environment. It results in the generation of ground tire rubber, which can be used to produce polymerrubber composites. It...
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Green Approaches in Rubber Recycling Technologies: Present Status and Future Perspective
PublikacjaAs 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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Polyurethane Nanocomposites Containing Reduced Graphene Oxide, FTIR, Raman, and XRD Studies
PublikacjaRecently, graphene and other graphene-based materials have become an essential part of composite science and technology. Their unique properties are not only restricted to graphene but also shared with derivative compounds like graphene oxide, reduced graphene oxide, functionalized graphene, and so forth. One of the most structurally important materials, graphene oxide (GO), is prepared by the oxidation of graphite. Though removal...
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Preparation and characterisation of solution-cast Nafion membrane
PublikacjaNafion is a commercial name for a perfluorosulfonic polymer, which has been developed in 1962 by Dupont de Nemours. This polymer consists of a polytetrafluoroethylene backbone and regular spaced long perfluorovinyl ether pendant side chains terminated by a sulfonate ionic group. These sulfonate groups are responsible for cation-exchange properties of Nafion. Thanks to the ion-exchange properties, water permeability, good chemical,...
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Some kind of joints in composite polymer bridges
PublikacjaContemporary, polymer composites bridge structures are of two types: truss or arch structures(with many joints along the length) and beam structures with limited number of joints. Both of them have special types of composite polymer decks. An ideal solution is to join advantages of two types of structuresdescribed below and create long span FRP beam bridge structure system using joints along the length. Theproblem is to find the...
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Composite GFRP U-shaped footbridge
PublikacjaThe paper presents proposals for the use of glass fiber reinforced polymer composites for the construction of engineering objects, known and commonly used in the shipbuilding industry. An example of a pedestrian footbridge was used in this case, which, despite the considerable thickness of the structural material, was made using infusion technology in one production cycle. The designed and produced footbridge span is durable, dynamically...
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Study on polymer modified road asphalt mixture
PublikacjaThe formulation of ternary asphalt-additives blend composed of crumb rubber : low-density polyethylene (CR : LDPE) and crumb rubber : textile fiber (CR : TF) couples, and quaternary asphalt additives-blend composed of (CR : LDPE : TF) triplets on the virgin asphalt to optimize the asphalt basic and rheological properties and to use the extrusion process of two or three additives to obtain composite materials of them, as well as...
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Morphology, Thermo-Mechanical Properties and Biodegradibility of PCL/PLA Blends Reactively Compatibilized by Different Organic Peroxides
PublikacjaReactive blending is a promising approach for the sustainable development of bio-based polymer blends and composites, which currently is gaining more and more attention. In this paper, biodegradable blends based on poly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA) were prepared via reactive blending performed in an internal mixer. The PCL and PLA content varied in a ratio of 70/30 and 55/45. Reactive modification of PCL/PLA...
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Recycling of Polyurethanes Containing Flame-Retardants and Polymer Waste Transformed into Flame-Retarded Polyurethanes
PublikacjaThe growing number of polyurethanes (PUs) produced every year has developed methods for their mechanical and chemical recycling which yield valuable products like substitutes for commercial polyols or flame-retardants. PUs can be produced in different shapes and forms (i.e., elastomers, flexible or rigid foams, coatings, etc.) using several different components (i.e., di- or polyisocyanates, ester- or ether-based polyols, low-molecular...
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High-performance method of carbon nanotubes modification by microwave plasma for thin composite films preparation
PublikacjaIn this work we present a simple and efficient method of nitrogen plasma modification of carbon nanotubes (CNTs). The process allows for treatment of the nanotubes in the form of powder with quite a high yield (65 mg of CNTs per hour). The modified carbon nanotubes contain approx. 3.8% of nitrogen, mostly in the pyridinic form. Plasma treated CNTs exhibit better dispersibility in water and higher electric capacitance than pristine...
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OIL-ASSISTED THERMO-MECHANICAL RECLAMATION OF GROUND TIRE RUBBER
PublikacjaNowadays, it is crucial to seek for the methods of by-products and waste utilization, considering both environmental and economic factors. The example of waste material generated in the massive amounts, which requires the attention is ground tire rubber generated during recycling of post-consumer car tires. It can be applied as a filler into different polymer matrices, but to enhance its effectivity proper modifications should...
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Degradation of polycaprolactone modified with TPS or CaCO3 in biotic/abiotic seawater
PublikacjaThis paper is an investigation of the polymer degradation process in two types of seawater (with and without microorganisms) sourced from the Baltic Sea. The chosen polymeric materials were polycaprolactone modified with either thermoplastic starch (PCL/TPS>85%) or calcium carbonate (60% PCL/40% CaCO3) compared directly against unmodified polycaprolactone. All samples were incubated for 28 weeks in seawater with and without microorganisms...
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Highly stable organic–inorganic junction composed of hydrogenated titania nanotubes infiltrated by a conducting polymer
PublikacjaA poly(3,4-ethylenedioxythiophene) conducting polymer doped with poly(2-styrene sulfonate) (pEDOT:PSS) was efficiently electrodeposited on a layer composed of ordered titania nanotubes. TiO2 nanotubes were formed during an anodization process and, after calcinations, a layer was subjected to hydrogen plasma. Hydrogenation leads to Ti(III) formation, a decrease in resistance, and a huge increase of donor density when compared with...
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Investigation into the Effect of Spinel Pigments on the Photostability and Combustion Properties of Ethylene-Norbornene Copolymer
PublikacjaMulticolor ethylene-norbornene (EN) composites filled with three different spinel pigments (Cobalt Green-PG50, Zinc Iron Yellow-PY 119, Praseodym Yellow-PY159) were prepared by melt mixing and characterized in terms of their stability under destructive environmental conditions. The EN films were subjected to accelerated aging by ultraviolet (UV) photooxidation for 300 h, 600 h, or 900 h. The mechanical performance of the EN composites...
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The use of GFRP tubes as load-bearing jackets in concrete-composite columns
PublikacjaThe 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...
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Effect of high loading of titanium dioxide particles on the morphology and selected properties of natural rubber-based composites
PublikacjaThe aim of this work was to prepare and characterize the natural rubber vulcanizates contained different amounts of titanium dioxide particles. At first rubber mixture was prepared using a laboratory two-roll mill and then samples were vulcanized in a hydraulic press. The formulation of rubber mixture and rubber-processing technique is based on our earlier investigations. Materials were obtained at the different titanium dioxide...
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Dynamic tests of composite footbridge segment – experimental and numerical studies
PublikacjaExperimental dynamic tests and numerical simulations of a 3 meters long segment of a footbridge made of polymer composites are presented in the paper. The span-length is reduced, however dimensions of cross-section are the same as the target footbridge. The segment structure is made of sandwich panels, which consist of fibre reinforced polymer (GFRP) laminates (skins) and a PET foam (core). The first part of the paper contains...
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Mathematical model of the energy consumption calculation during the pine sawn wood (Pinus sylvestris L.) drying process
PublikacjaThe article presents the modification of the existing mathematical model to calculate energy consumption during conventional drying process. Apart from energy consumption the model permits to estimate the time of high-temperature drying process. The drying medium is air and superheated steam mixture. The obtained calculation results were compared with conducted experimental tests of drying square-edged sawn sapwood timber (Pinus...