Search results for: PU CROSSLINKING REACTIONS
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Cavitation-Based Processes for Water and Wastewater Treatment
PublicationCavitation based on advanced oxidation processes (Cav-AOPs) is interesting alternatives for already implemented wastewater treatment technologies. Destructive and strongly undesirable phenomena in the industry, i.e., cavitation, revealed to be useful in a positive manner as a source of energy for chemical reactions. During the implosion of cavitation bubbles, focused energy and resulting high temperature and pressure allows to...
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Two complementary approaches for the synthesis and isolation of stable phosphanylphosphaalkenes
PublicationPhospha-Wittig (phosphanylphosphinidene titanium(IV) complex) and phospha-Peterson (lithiated diphosphane) reactions were used to obtain phosphanylphosphaalkenes with the general formula XYC=P-PtBu2 (X = alkyl, aryl group or H; Y = alkyl or aryl group). Therefore, two series of reactions with different ketones and aldehydes were performed. An examination revealed that the two methods are complementary. For smaller carbonyl compounds,...
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General route for the synthesis of terminal phosphanylphosphido complexes of Zr(IV) and Hf(IV): Structural investigations of the first zirconium complex with a phosphanylphosphido ligand
PublicationReactions of R2P-P(SiMe3)Li with [Cp2MCl2] (M = Zr, Hf) in hydrocarbons yield the related terminal phosphanylphosphidocomplexes [Cp2M(Cl){(Me3Si)P-PR2-jP1}] (R = iPr and tBu). The solid state structures of [Cp2M(Cl){P(SiMe3)-PiPr2-jP1}] (M = Zr, Hf) were established by single crystal X-ray diffraction studies. The phosphido-P atoms adopt almost planar geometries and the phosphanyl P atoms adopt pyramidal geometries. The reaction...
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The Role of Proteins in Food
PublicationThis chapter describes the effect of proteins on the sensory attributes and the biological value and safety of foods. The role of proteins depends on their amino acid composition and structure, on changes due to storage and processing, as well as on interactions with other food components. The effect on the sensory quality of foods is brought about by hydrophobicity, solubility, water holding capacity, gelling, film formation,...
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Recovery of Valuable Materials and Methods for Their Management When Recycling Thin-Film CdTe Photovoltaic Modules
PublicationDue to the development of new photovoltaic technologies, there is a need to research new recycling methods for these new materials. The recovery of metals from photovoltaic (PV) modules would reduce the consumption of raw materials. Therefore, the development of recycling technologies for used and damaged modules of newer generations is important for environmental reasons. The aim of the research is to shed light on the nature...
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Efficient synthesis and antifungal investigation of nucleosides’ quaternary ammonium salt derivatives
PublicationQuaternary ammonium salts are a group of compounds with diverse biological properties, the most important of which are their antiviral, antibacterial, and antifungal activities. The quaternization reactions of 5'-O-tosyl derivatives of uridine and thymidine with triethylamine, trimethylamine, 4-(N ,N -dimethylamino)pyridine, 2-methylpyridine, and pyridine are described in this article. Two of the synthesized compounds are exceptional...
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Surface Treatment of Rubber Waste
PublicationThis chapter deals with the study of different approaches to improve the compatibility of waste rubber with polymeric matrixes of high density polyethylene (HDPE) by using surface treatments to increase adhesion. Different surface treatments such as etching with sulphuric and nitric acids, the use of a silane as a coupling agent and chlorination with trichloroisocyanuric acid (TCI) have been applied. The modification of waste rubber...
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Curing epoxy with electrochemically synthesized Zn Fe3-O4 magnetic nanoparticles
PublicationCathodic electrodeposition (CED) was applied in synthesis of undoped and zinc (Zn) doped Fe3O4 nanoparticles. Changes in the lattice structure of nanoparticles were monitored using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) supported by dispersive X-ray spectrometry (EDS), and vibrating sample magnetometry (VSM). Detailed analyses explored the formation of ZnxFe3–xO4 nanoparticles with x ≈ 0.1,...
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IZOLACJA I IDENTYFIKACJA NATURALNYCH SUBSTANCJI BARWIĄCYCH OBECNYCH W PRÓBKACH FARB ARTYSTYCZNYCH I TKANINACH POCHODZENIA HISTORYCZNEGO
PublicationNatural organic dyes are group of substances that belong to various types of chemical compounds. The most commonly used in paintings and dyeing textiles were naturally occurring dyestuffs from group of anthraquinones, flavones and indigoid dyes. Identification of coloring substances present in historical artistic paints provides relevant information for a wide range of specialists dealing with works of art and in the field of conservation science....
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Impedance of cation-coupled electron transfer reaction: Theoretical description of one pathway process
PublicationIt has been assumed that cation electron coupled charge transfer can be conducted in accordance with two mutually coupled reactions. Using a differential method an expression was introduced which describes the impedance of a cation electron coupled transfer reaction. Also, an electrical equivalent circuit has been defined. The total faradaic impedance is the sum of electron transfer impedance and cation transfer impedance. Issues...
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Kinetics of cross-linking processes of fast-curing polyurethane system
PublicationThis work focuses on the application of thermal analysis and kinetics investigations to analyze chemical processes during cross-linking of the complex fast-curing polyurethane system. Non-isothermal Differential Scanning Calorimetry (DSC) measurements were performed for both stoichiometric mixtures of polyol and isocyanate component and for mixture with large isocyanate excess. Isoconversional methods were used to calculate initial...
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Formation of polyphosphorus ligands mediated by zirconium and hafnium complexes
PublicationThe reactions of R2P–P(SiMe3)Li (R = tBu, iPr, iPr2N) with [Cp2MCl2] (M = Zr, Hf), [Cp∗CpZrCl2] and [CpZrCl3] yielded polyphosphorus (mainly hexaphosphorus) compounds which can be viewed as intermediates between R2P–P(SiMe3)Li and derivatives of 1,2,3,4-tetraphosphabicyclo[1.1.0] butane. Thus R2P–P(SiMe3)Li can act as a building block for the formation of the P2 ligand and the R2P–P(P2) and R2P–P(P2)P–PR2 moieties. Solid state...
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RecA Proteins from Deinococcus geothermalis and Deinococcus murrayi - Cloning, Purification and Biochemical Characterisation
PublicationEscherichia coli RecA plays a crucial role in recombinational processes, the induction of SOS response and mutagenic lesion bypasses. It has also been demonstrated that RecA protein is indispensable when it comes to the reassembly of shattered chromosomes in gamma-irradiated Deinococcus radiodurans, one of the most radiation-resistant organisms known. Moreover, some functional differences between E. coli and D. radiodurans RecA...
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Transparent nanocomposite coatings based on epoxy and layered double hydroxide: Nonisothermal cure kinetics and viscoelastic behavior assessments
PublicationLayered double hydroxide (LDH) has a particular place in clay family because of its flame retardant action. The nanoplatelet-like structure of LDH makes possible development of polymer composites with cationic or anionic nature structures in which macromolecules are positioned in between nanoplatelet galleries. In this work, neat epoxy and its transparent nanocomposite coatings with sodium dodecylbenzene sulfonate (SDBS)-modified...
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Evaluation and rationale of the performance of several elastomeric composites incorporating devulcanized EPDM
Publicationthylene Propylene Diene rubber (EPDM), is present in many applications. However, its crosslinked structure makes difficult its recycling. The use of devulcanized EPDM, (dEPDM) as a component of elastomeric composites, is a real possibility to reuse EPDM scraps. In this study, three matrices (natural rubber (NR), styrene butadiene rubber (SBR) and EPDM rubber) have been tested including devulcanized EPDM as a recycled component....
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The changes of crosslink density of polyurethanes synthesised with using recycled component. Chemical structure and mechanical properties investigations.
PublicationThis paper aims at the utilisation of glycerolysate (Gly) obtained in polyurethane recycling process by means of crude glycerine, which has in its structure hydroxyl end groups that allow for further processing. Polyurethanes (PUs) were synthesised using prepolymer method with the mixture of neat polyol and glycerolysate, in different ratios, with 4,4-diphenylmethane diisocyanate (MDI). The prepolymer was subsequently extended...
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AFM imaging of surface of modern soldering alloy
Open Research DataFollowing the announcement in 2006 of European Union directives aimed at limiting the use of lead in electronic products, there was an urgent need to use lead-free solders in the electronics industry. Due to production requirements, it is necessary to use solders with different melting points. To replace the low-melting eutectic Sn 37 wt. Pb, the most...
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Ceria Based Protective Coatings for Steel Interconnects Prepared by Spray Pyrolysis
PublicationStainless steels can be used in solid oxide fuel/electrolysis stacks as interconnects. For successful long term operation they require protective coatings, that lower the corrosion rate and block chemical reactions between the interconnect and adjacent layers of the oxygen or the hydrogen electrode. One of the promising coating materials for the hydrogen side is ceria. Using standard sintering techniques, ceria sinters at around...
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Phosphinoborenium cations stabilized by N-heterocyclic carbenes: synthesis, structure, and reactivity
PublicationPhosphinoborenium cations stabilized by N-heterocyclic carbenes (NHCs) were synthesized via the reaction of bromo(phosphino)boranes with NHCs. Their structures were investigated by heteronuclear magnetic resonance spectroscopy, X-ray diffraction, and density functional theory calculations. They possess a planar trigonal boron center directly bonded with the pyramidal phosphanyl group (PR2) and can be treated as cationic phosphinoboranes....
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Polyurethanes modified with natural polymers for medical application. I. Polyurethanes/ Chitosan and polyurethane/collagen.
PublicationFor over three decades polyurethanes (PUR or PU) have been reported for application in a variety of medical devices. These polymers consist of hard and soft segments, which allow for more subtle control of their structure and properties. By varying the composition of the different segments, properties of PURcan be tuned up for use in many areas of medicine. Recently there is a great interest in modification of biomedical PUR with...
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Synthetic Principles Determining Local Organization of Copolyesters Prepared from Lactones and Macrolactones
PublicationA highly effective and facile technique for catalytic ring-opening copolymerization (cROP) of lactones viz. ε- caprolactone and ε-decalactone with ω-pentadecalactone is being described. The reactions were mediated by Zn- and Cabased tridentate Schiff base complexes and benzyl alcohol as initiator. The catalysts were successfully employed for the preparation of numerous block and random copolymers. To unravel the composition of...
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Synthesis and antimicrobial activity of 6-sulfo-6-deoxy-D-glucosamine and its derivatives
Publication6-Sulfo-6-deoxy-D-glucosamine (GlcN6S), 6-sulfo-6-deoxy-D-glucosaminitol (ADGS) and their N-acetyl and methyl ester derivatives have been synthesized and tested as inhibitors of enzymes catalyzing reactions of the UDP-GlcNAc pathway in bacteria and yeasts. GlcN6S and ADGS at micromolar concentrations inhibited glucosamine-6-phosphate (GlcN6P) synthase of microbial origin. The former was also inhibitory towards fungal GlcN6P N-acetyl...
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Novel Diazocrowns with Pyrrole Residue as Lead(II) Colorimetric Probes
PublicationNovel 18- and 23-membered diazomacrocycles were obtained with satisfactory yields by diazocoupling of aromatic diamines with pyrrole in reactions carried under high dilution conditions. X-ray structure of macrocycle bearing five carbon atoms linkage was determined and described. Compounds were characterized as chromogenic heavy metal ions receptors. Selective color and spectral response for lead(II) was found in acetonitrile and...
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Modelling of subarachnoid space width changes in apnoea resulting as a function of blood flow parameters
PublicationDuring apnoea, the pial artery is subjected to two opposite physiological processes: vasoconstriction due to elevated blood pressure and vasorelaxation driven by rising pH in the brain parenchyma. We hypothesized that the pial artery response to apnoea may vary, depending on which process dominate. Apnoea experiments were performed in a group of 19 healthy, non-smoking volunteers (9 men and 10 women). The following parameters...
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The Response of Selected Domestic Capital Markets on the Development of COVID-19 Pandemic – a Broader View
PublicationObjective: The study examines how the record of the first, hundredth, thousandth, ten-thousandth, one-hundred-thousandth, and millionth cases of COVID-19 affected investor behaviour in capital markets. It also looks at whether the month in which the first case was recorded in a given market affected the direction and strength of investor reactions. Lastly, it verifies whether the two announcements made by the WHO related to COVID-19...
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Performance of electrochemical immunoassays for clinical diagnostics of SARS-CoV-2 based on selective nucleocapsid N protein detection: Boron-doped diamond, gold and glassy carbon evaluation
PublicationThe 21st century has already brought us a plethora of new threats related to viruses that emerge in humans after zoonotic transmission or drastically change their geographic distribution or prevalence. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first spotted at the end of 2019 to rapidly spread in southwest Asia and later cause a global pandemic, which paralyzes the world since then. We have designed novel...
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Shape memory thin films of Polyurethane: Does graphene content affect the recovery behavior of Polyurethane nanocomposites?
PublicationThin nanocomposite films of polyurethane have received remarkable attention due to their shape memory properties. As most of the reports focus on the beneficial aspects of the presence of nanofillers such as graphene nanoplatelets (GNPs) introduced into shape memory polymers, some research results reveal the opposite trend. The polyether/polyester-based polyurethane was synthesized through a condensation polymerization and the...
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Photocatalysts for Solar Energy Conversion
PublicationPhotocatalytic oxidation over suspended solid photocatalysts (e.g., titanium dioxide) has been proposed as a sustainable process for treatment and purification of water and wastewater as well as the process for photoconversion of solar energy to hydrogen, methane, and other low hydrocarbons. Solar radiation could be used to drive heterogeneous electrochemical reactions at the surface of an optically active photocatalyst (e.g.,...
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Benzene-induced hydro(solvo)thermal synthesis of Cu2+ and Zn2+ coordination polymers based on 1,3-benzenedicarboxylate
PublicationHydro(solvo)thermal reactions of Cu(NO3)2·2.5H2O or Zn(NO3)2·6H2O with 1,3-H2bdc provided two structurally different coordination polymers; a 2D network “metallacalixarene” based on the paddlewheel-type cluster with the formula [Cu(1,3-bdc)·H2O]·H2O (1) and a 3D framework [Zn(1,3-bdc)] (2), respectively. The use of a base was unnecessary in this synthesis; however, the presence of benzene played a crucial role in the crystallization...
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Low energy electron attachment to platinum(II) bromide (PtBr2)
PublicationtDissociative electron attachment to PtBr2in the gas phase was studied in the low electron energy rangefrom zero up to 10 eV with an energy resolution of 150 meV. The experiments were carried out using ahemispherical electron monochromator coupled with a quadrupole mass spectrometer and pulse count-ing acquisition system. The only anion observed was Br−. This ion is formed at three resonance electronenergies: 0.4 eV, 1.2 eV and...
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Autonomous Driver Based on an Intelligent System of Decision-Making
PublicationThe paper presents and discusses a system (xDriver) which uses an Intelligent System of Decision-making (ISD) for the task of car driving. The principal subject is the implementation, simulation and testing of the ISD system described earlier in our publications for the task of autonomous driving. The design of the whole ISD system is a result of a thorough modelling of human psychology based on an extensive literature study. Concepts...
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Evidence for solid state electrochemical degradation within a small molecule OLED
PublicationAcridone derivative have been synthesised and used as OLED (Organic Light Emitting Diode) emitters which were found to be electroactive. Electrochemical investigations showed a side reaction takes place inside an active layer which diminished the overall device efficiency. By using a dopant and host active layer architecture, the formation of the by product was removed. The by-product was identified as a σ-dimer formed inside an...
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Application of gas chromatography to evaluate the quality of rapeseed oil
PublicationTwo-dimensional gas chromatography is an analytical technique, which is increasingly being used in food research. Through the analysis of volatile fraction, it is possible to determine the quality of food products. One of the reasons for the deterioration of food is thermal degradation. Products that are often subject to degradation reactions due to temperatures are edible oils. In the thesis, the results of edible oils with different...
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1,3,4-Thiadiazole-based diamides: Synthesis and complexation properties
PublicationAromatic diamides, derivative of 2,6-pyridinedicarboxylic acid and isophthalic acid, bearing 1,3,4-thiadiazole residue were prepared with satisfactory yields in conventional procedures and microwave stimulated reactions. X-ray structure of N,N-bis (1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide (2) DMSO solvate (2DMSO) was described. Selective zinc(II), lanthanum(III), terbium(III) and L-tyrosine recognition was found for N,N-bis(1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide...
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Exfoliated graphite with spinel oxide as an effective hybrid electrocatalyst for water splitting
PublicationThe aim of the conducted research was to develop hybrid nanostructures formed from MnCo2O4 and exfoliated graphite. Carbon added during the synthesis allowed for obtaining a well-distributed MnCo2O4 particle size with exposed active sites contributing to the increased electric conductivity. The influence of the weight ratios of carbon to a catalyst for hydrogen and oxygen evolution reactions was investigated. The new bifunctional...
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Literature update of analytical methods for biogenic amines determination in food and beverages
PublicationBiogenic amines (BAs) have been reported in a variety of foods, such as fish, meat, cheese, and wines. The formation of BAs in food by the microbial decarboxylation of amino acids can result in human allergic reactions, characterized by difficulty in breathing, rash, vomiting, and hypertension. Control measures to prevent biogenic amine formation in foods and/or reduce their levels should be considered. Therefore, monitoring of...
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VUV photofragmentation of the six-membered heterocyclic molecules containing oxygen
PublicationCancer is a significant public health concern worldwide, which results in millions of deaths each year. The standard cure routine for cancer is surgery, and nowadays, radiotherapy or a hadrontherapy. Depending on the type of cancer, patients may undergo additional treatment, including targeted therapy. A combination of radio- or hadron-therapy with proper drug treatment can inhibit the proliferation of cancer cells and thus can...
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Chitosan-based inks for 3D printing and bioprinting
PublicationThe advent of 3D-printing/additive manufacturing in biomedical engineering field has introduced great potential for the preparation of 3D structures that can mimic native tissues. This technology has accelerated the progress in numerous areas of regenerative medicine, especially led to a big wave of biomimetic functional scaffold developments for tissue engineering demands. In recent years, the introduction of smart bio-inks has...
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Mass spectrometry based identification of geometric isomers during metabolic stability study of a new cytotoxic sulfonamide derivatives supported by quantitative structure-retention relationships
PublicationA set of 15 new sulphonamide derivatives, presenting antitumor activity have been subjected to a metabolic stability study. The results showed that besides products of biotransformation, some additional peaks occurred in chromatograms. Tandem mass spectrometry revealed the same mass and fragmentation pathway, suggesting that geometric isomerization occurred. Thus, to support this hypothesis, quantitative structure-retention relationships...
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H2O˙+ and OH+ reactivity versus furan: experimental low energy absolute cross sections for modeling radiation damage
PublicationRadiotherapy is one of the most widespread and efficient strategies to fight malignant tumors. Despite its broad application, the mechanisms of radiation-DNA interaction are still under investigation. Theoretical models to predict the effects of a particular delivered dose are still in their infancy due to the difficulty of simulating a real cell environment, as well as the inclusion of a large variety of secondary processes. This...
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Synthesis of compounds with C-P-P and C=P-P bond systems based on the phospha-Wittig reaction
PublicationA reactivity study of a β-diketiminate titanium(III) phosphanylphosphido complex [MeNacNacTi(Cl){η2-P(SiMe3)-PtBu2}] (1) towards ketones such as benzophenone, 9-fluorenone, acetophenone, cyclopentanone, cyclohexanone and cycloheptanone is reported. The reactions of 1 with aromatic ketones (without α-protons) directly lead to the Ti(III) complex [MeNacNacTi(μ2-Cl)(OSiMe3)] (5) as well as Ti(IV) complexes with the pinacol condensation...
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Effect of kenaf fibre modification on morphology and mechanical properties of thermoplastic polyurethane materials
PublicationThe presented study examined the morphology and mechanical properties of biocomposites obtained from kenaf natural fibre and thermoplastic polyurethane. Kenaf was modified using various methods, namely: acetylation, blocked isocyanate, maleic anhydride and permanganate treatment. Those methods and ways of carrying out of surface modifications were not studied before on kenaf/thermoplastic polyurethane composites. Different fibre...
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An unorthodox view on the problem of tracking facial expressions
PublicationRecent developments in imaging cameras has opened a new way of analyzing facial expression. We would like to take advantage from this new technology and present a method of imaging and processing images of human face as a response to the particular stimuli. The response in this case is represented by the facial expressions and the stimuli are still images representing six basic emotions according to Eckmann. Working hypothesis...
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Environmental Fate of Two Psychiatric Drugs, Diazepam and Sertraline: Phototransformation and Investigation of their Photoproducts in Natural Waters
PublicationExperimental studies were conducted to investigate the photodegradation of diazepam and sertraline, two of the most frequently used psychiatric drugs, induced by xenon lamp irradiation, which overlap the sunlight spectra, and natural sunlight. Degradation kinetics was established indicating the occurrence of autocatalytic reactions. The application of liquid chromatography coupled to quadrupole time-of-flight mass spectrometry...
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The Fate of BTEX Compounds in Ambient Air
PublicationAs a result of the industrialization and urbanization in the world, human pressure on the environment is intensifying, leading to detrimental changes in both biotic and abiotic compartments. One of the many consequences of this state of affairs is the increasing rate of emission into the atmosphere of volatile organic compounds, including the so-called BTEX (benzene, ethylbenzene, toluene, xylenes) compounds. The authors review...
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Orthotropic membrane as a mechanical model of surgical implant in abdominal hernia repair
PublicationEven though the incisional hernia repair surgery is a well known procedure, mechanical properties of the tissue-implant system are unknown so the implantation of the repairing mesh is quite intuitive and, recurrences of the illness still take place. The main objective of the study is to define an operated hernia model that can be used for surgery planning and the assessment of the repair persistence. The load applied to the structure...
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An unorthodox view on the problem of tracking facial expressions
PublicationRecent developments in imaging cameras has opened a new way of analyzing facial expression. We would like to take advantage from this new technology and present a method of imaging and processing images of human face as a response to the particular stimuli. The response in this case is represented by the facial expressions and the stimuli are still images representing six basic emotions according to Eckmann. Working hypothesis...
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abiotic degradation of chlorinated ethanes and ethenes in water
PublicationIntroduction Chlorinated ethanes and ethenes are among themost frequently detected organic pollutants of water. Theirphysicochemical properties are such that they can contaminateaquifers for decades. In favourable conditions, they canundergo degradation. In anaerobic conditions, chlorinatedsolvents can undergo reductive dechlorination.Degradation pathways Abiotic dechlorination is usuallyslower than microbial but abiotic dechlorination...
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Environmental fate of BTEX compounds in ambient air
PublicationAs a result of the industrialization and urbanization in the world, human pressure on the environment is intensifying, leading to detrimental changes in both biotic and abiotic compartments. One of the many consequences of this state of affairs is the increasing rate of emission into the atmosphere of volatile organic compounds, including the so-called BTEX (benzene, ethylbenzene, toluene, xylenes) compounds. The article reviews...
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Measurements of flicker noise in supercapacitor cells
PublicationFlicker noise (1/f-like noise) is often used to assess the quality of various materials and devices. This phenomenon has been observed in different electrochemical devices or reactions (e.g., smart windows, pitting corrosion events). In our exploratory studies we consider how to measure and utilize 1/f noise for the quality assessment of supercapacitors. This task requires special attention because of enormous capacitance of the...