Wyszukiwarka
Filtry
wszystkich: 710
wybranych: 571
-
Katalog
Filtry wybranego katalogu
Wyniki wyszukiwania dla: POLYESTERS, POLYMERS, SOLID-STATE POLYMERIZATION
-
Novel Biomass-Based Polymers: Synthesis, Characterization, and Application
PublikacjaA wide range of polymers were prepared from biomass-derivatives, using different polymerization mechanisms. Well-defined, fully hydroxy-functional polyesters based on aliphatic diols were synthesized, using either conventional metal-based catalysts or the organic superbase 1,5,7-triazabicyclododecene (TBD). Unsaturated polyesters were also made, offering additional functionality to these biobased resins. Metal-catalyzed or enzymatic...
-
Fully Isohexide-Based Polyesters: Synthesis, Characterization, and Structure-Properties Relations
PublikacjaHere we present a novel series of biobasedpolyesters solely based on renewable isohexide building blocks,synthesized via melt polymerization. The recently developedisoidide dicarboxylic acid (IIDCA) was polymerized with rigidrenewable diols such as isosorbide (IS), isomannide (IM),isoidide (II), and the novel 2,5-methylene-extended isoididedimethanol (IIDML). Both IIDCA and IIDML weredeveloped to increase the reactivity of the...
-
Semicrystalline Polyesters Based on a Novel Renewable Building Block
PublikacjaIsohexides, like e.g. isosorbide, are well-known carbohydrate-based rigid diols which are capable of dramatically increasing the glass transition temperature of polyesters. However, their relatively low reactivity has thus far hampered large-scale industrial applications in the polymer field. Recently, with the aim to increase reactivity while at the same time retain rigidity, we have developed a new isoidide dicarboxylic acid...
-
Unsaturated, biobased polyesters and their cross-linking via radical copolymerization
PublikacjaBiobased, unsaturated polyesters derived from isosorbide, maleic anhydride and succinic acid were synthesized and characterized. The presence of maleic anhydride units in the structure of the polyesters allowed converting them into cured coatings by radical copolymerization with cross-linking agents such as 2-hydroxyethyl methacrylate, N-vinyl-2-pyrrolidinone, acrylic acid or methacrylamide. The investigated polyesters were obtained...
-
Reactive extrusion of biodegradable aliphatic polyesters in the presence of free-radical-initiators: A review
PublikacjaNowadays, growing attention is being paid to the environment and sustainability, what fully justified research works focused on modification of biodegradable polymers and their composites. In this field of research reactive extrusion seems to be the most promising approach, which fits well to sustainable development strategy. In In the present work, the in-situ modification of biodegradable aliphatic polyesters and the compatibilization...
-
Towards sugar-derived polyamides as environmentally friendly materials
PublikacjaAs part of our ongoing study investigating isohexide-based polyamides, we have synthesized isosorbide(bis(propan-1-amine)) (DAPIS) and studied its reactivity in the polymerization towards fully biobased polyamides. Polycondensation of nylon salts with various contributions of DAPIS afforded a family of homo- and copolyamides, which were characterized using complementary spectroscopic techniques. The chemical structure of the materials...
-
Reactive extrusion of bio-based polymer blends and composites – Current trends and future developments
PublikacjaReactive extrusion is a cost-effective and environmentally-friendly method to produce new materials with enhanced performance properties. At present, reactive extrusion allows in-situ polymerization, modification/functionalization of polymers or chemical bonding of two (or more) immiscible phases, which can be carried out on commonly used extrusion lines. Although reactive extrusion has been known for many years, its application...
-
Novel, Fully Biobased Semicrystalline Polyamides
PublikacjaNovel, semicrystalline polyamides and co(polyamides) were synthesized from biobased sebacic acid (SA), 2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydroiditol (diaminoisoidide, DAII) as well as from 1,4-diaminobutane (DAB), also known as putrescine in nature. Low molecular weight polyamides were obtained by melt polycondensation of the salts based on these monomers or by interfacial polycondensation. In order to increase their molecular...
-
Topological behavior mimicking ethylene–hexene copolymers using branched lactones and macrolactones
PublikacjaPolyolefins are of paramount importance in the world of polymers due to their technological and economic potential.1 However, their nonpolar character significantly restricts the compatibility and adhesion properties, which consequently limits their versatility. Moreover, an intensified demand for materials from renewable resources can also become a problematic venture for the current polyolefin industry.2 Although Braskem and...
-
Waterborne polyesters partially based on renewable resources
PublikacjaA new experimental approach for preparing biobased, water-soluble polyesters via titanium(IV) n-butoxide-catalyzed bulk polycondensation is presented. In the described method polymers were obtained from isosorbide, maleic anhydride and poly(ethylene glycol). The chemical structure of the synthesized polyesters was confirmed using 2D NMR spectroscopy and by titration methods. Careful analysis of 2D NMR spectra viz. Correlation Spectra...
-
Synthesis and characterization of novel renewable polyesters based on 2,5-furandicarboxylic acid and 2,3-butanediol
PublikacjaNovel polyesters from 2,5-furandicarboxylic acid or 2,5-dimethyl-furandicarboxylate and 2,3-butanediol have been synthesized via bulk polycondensation catalyzed by titanium (IV) n-butoxide, tin (IV) ethylhexanoate, or zirconium (IV) butoxide. The polymers were analyzed by size exclusion chromatography, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy (FTIR), matrix-assisted laser ionization-desorption...
-
Multivariate Assessment of Procedures for Molecularly Imprinted Polymer Synthesis for Pesticides Determination in Environmental and Agricultural Samples
PublikacjaIn the case of quantitative and qualitative analysis of pesticides in environmental and food samples, it is required to perform a sample pre-treatment process. It allows to minimalize the impact of interferences on the final results, as well as increase the recovery rate. Nowadays, apart from routinely employed sample preparation techniques such as solid-phase extraction (SPE) or solid-phase microextraction (SPME), the application...
-
Progress in ATRP-derived materials for biomedical applications
PublikacjaThe continuing wave of technological breakthroughs and advances is critical for engineering well- defined materials, particularly biomaterials, with tailored microstructure and properties. Over the last few decades, controlled radical polymerization (CRP) has become a very promising option for the synthesis of precise polymeric materials with an unprecedented degree of control over mo lecular architecture. Atom transfer radical...
-
Preparation and characterization of dummy-template molecularly imprinted polymers as potential sorbents for the recognition of selected polybrominated diphenyl ethers
PublikacjaThe main aim of this work was to conduct the preliminary/basic research concerning the preparation process of a new dummy molecularly imprinted polymer (DMIP) materials. Developed DMIPs were proposed as a sorption material in solid-phase extraction (SPE) technique for recognition of selected low mass polybrominated diphenyl ethers (PBDEs) e PBDE-47 and PBDE-99. Four new DMIPs were synthesized employing bulky polymerization technique...
-
Computational modeling of molecularly imprinted polymers as a green approach to the development of novel analytical sorbents
PublikacjaThe development of novel molecularly imprinted polymers (MIP) sorbents for specific chemical compounds require a lot of tedious and time-consuming laboratory work. Significant quantities of solvents and reagents are consumed in the course of the verification of appropriate configurations of polymerization reagents. Implementation of molecular modeling in the MIP sorbent development process appears to provide a solution to this...
-
Core-Shell Nanoparticles with Hyperbranched Poly(arylene-oxindole) Interiors
PublikacjaCore-shell type star polymers composed of poly(tert-butyl acrylate) (poly(t-BuA)) arms and 100% hyperbranched poly(arylene-oxindole) interiors were synthesized via the "core-first" method. Atom transfer radical polymerization of t-BuA initiated by 2-bromopropionyl terminal groups of the hyperbranched core was applied for the synthesis of the stars. The resultant star structures were characterized by gel permeation chromatography...
-
Introduction to MIP synthesis, characteristics and analytical application
PublikacjaOne of the trends in analytical chemistry is associated with designing and developing new types of sample preparation techniques, which might significantly increase the efficiency and selectivity of the analytes isolation or/and preconcentration process. One of the most widely employed solutions are selective sorption materials, defined as molecularly imprinted polymers (MIPs), as well as the sorbents with the molecular fingerprint....
-
Preparation of Well-Compatibilized PP/PC Blends and Foams Thereof
PublikacjaThe performance of polypropylene-poly(ethylene brassylate) block and graft copolymers and a polypropylene-polycaprolactone graft copolymer as compatibilizers for polypropylene-rich polypropylene/bisphenol A polycarbonate (PP/PC, 80/20 wt/wt) blends was elucidated. The copolymers were synthesized either by metal-catalyzed ring-opening polymerization or transesterification of a presynthesized polyester, initiated by hydroxyl-functionalized...
-
Bioactive polyurethanes applied as a surgical implants
PublikacjaSynthetic materials are applied in many branches of the industry, i.a. in medicine as a casing of apparatus, elements of artificial organs (hearts, blood vessels), catheters, wound healings, intra aortic balloons, mammary implants to mention but a few. Polymeric material used in such applications must be distinguished by a good biocompatybility. Since many years extensive research are employed to develop a new polymers that can...
-
In-Situ Processing of Biocomposites via Reactive Extrusion
PublikacjaLaw regulations, economic and environmental factors are the main causes for the rapidly growing interests in biocomposites’ research, conducted currently in a number of academic and industrial scientific centers. However, weak polymer matrix/filler interactions, common in biocomposites, result in unsatisfactory mechanical properties, which limit their practical applications. From many attempts performed to solve this problem, in-situ...
-
PREPARATION AND CHARACTERIZATION OF CoFe2O4/TiO2-PANI HYBRID NANOCOMPOSITE WITH MAGNETIC AND PHOYOCATALYTIC ACTIVITY
PublikacjaHybrid nanocomposites consisting of inorganic component and organic conducting polymer are promising materials, which can be applied in heterogeneous photocatalysis. Titanium(IV) oxide is widely used photocatalysts due to its non-toxicity, low cost and chemical stability. The main disadvantage of TiO2 is low photocatalytic activity under visible light. Conducting polymers, also known as conjugated polymers are polymer materials...
-
Unprecedented Adhesive Performance of Propylene-Based Hydroxyl Functionalized Terpolymers
PublikacjaThe synthesis of hydroxyl functionalized propylene-based terpolymers and their performance as hot melt adhesives were investigated. The products comprise uniformly distributed butyl and 4-hydroxyl-butyl branches along the polypropylene backbone. Despite the low hydroxyl-functionality level of ≤ 0.5 mol%, hydroxyl functionalized terpolymers show formidable adhesion to aluminum and steel providing an adhesive strength exceeding 16...
-
Degradable poly(ester-ether) urethanes of improved surface calcium deposition developed as novel biomaterials
PublikacjaBones, which are considered as hard tissues, work as scaffold for human body. They provide physical support for muscles and protect intestinal organs. Percentage of hard tissues in human body depends on age, weight, and gender. Human skeleton consists of 206 connected bones. Therefore, it is natural that the hard-tissue damage such as fractures, osteoporosis, and congenital lack of bone may appear. The innovative way of bone healing...
-
Structural, mechanical and thermal behavior assessments of PCL/PHB blends reactively compatibilized with organic peroxides
PublikacjaThe efficiency of two commercially available organic peroxides, dicumyl peroxide (DCP) and di-(2-tert-butyl-peroxyisopropyl)-benzene (BIB), during reactive processing of poly (ε-caprolactone)/poly (3-hydroxybutyrate) (PCL/PHB) blends was investigated. The changes in chemical structure of PCL/PHB blends, as a function of organic peroxide type (DCP/BIB) and content (in range: 0–1.0 parts by weight - pbw), were characterized by Fourier...
-
Theoretical study of polymerization mechanism of p-xylylene based polymers
PublikacjaObliczenia kwantowe mechanizmu polimeryzacji parylenów, opartych o cząsteczki p-ksylilenów. Praca zawiera wyniki szczegółowych obliczeń wszystkich etapów polimeryzacji, wnioski dotyczące znalezionych stanów kwantowych i energetyki poszczególnych etapów procesu.
-
Theoretical Study of Polymerization Mechanism of p-Xylylene Based Polymers
Publikacja -
Characterization of Aliphatic Polyesters Synthesized via Enzymatic Ring-Opening Polymerization in Ionic Liquids
Publikacja -
Shape memory thin films of Polyurethane: Does graphene content affect the recovery behavior of Polyurethane nanocomposites?
PublikacjaThin 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...
-
Recent advancements in molecularly imprinted polymers for the removal of heavy metal ions and dyes
PublikacjaContamination set off by highly toxic metal ions and dyes is a big threat to the environment and living beings. Various industries like metal plating, mining, pesticides, battery manufacturing, and dyeing release metal ions and toxic dyes directly into the water. It is necessary to remove these toxic substances from the environment. Molecular imprinting technology (MIT) got a lot of attention in the last two decades because of...
-
Chemical Characteristics and Thermal Oxidative Stability of Novel Cold-Pressed Oil Blends: GC, LF NMR, and DSC Studies
PublikacjaPlant oils contain a high content of unsaturated fatty acids. Studies of food products have revealed a considerable disproportion in the ratio of ω6 to ω3. This article presents information on the healthful qualities of eight new oil blends that contain a beneficial proportion of ω6 to ω3 fatty acids (5:1), as well as their degradation during heating at 170 and 200 °C. The fatty acid profile was analyzed by gas chromatography (GC),...
-
Solid-State Modification of Poly(butylene terephthalate) with a Bio-Based Fatty Acid Dimer Diol Furnishing Copolyesters with Unique Morphologies
PublikacjaCopolyesters based on poly(butylene terephthalate) (PBT) and a bio-based fatty acid dimer diol (FADD) were prepared by solid-state modification (SSM). The chemical incorporation of the FADD into the backbone of the PBT was proven using various techniques. It was clear that the incorporation rate was diffusion-limited rather than reaction-limited. From quantitative 13C NMR a nonrandom chemical microstructure was obtained at all...
-
Potentiometric Oxygen Sensor with Solid State Reference Electrode
PublikacjaThe concentration or the partial pressure of oxygen in an environment can be determined using different measuring principles. For high temperature measurements of oxygen, ceramic-based sensors are the most practical. They are simple in construction, exploration and maintenance. A typical oxygen potentiometric sensor consists of an oxygen ion conducting solid electrolyte and two electrodes deposited...
-
Enzymatic Polymerization of Cyclic Monomers in Ionic Liquids as a Prospective Synthesis Method for Polyesters Used in Drug Delivery Systems
Publikacja -
Ammonia Gas Sensors: Comparison of Solid-State and Optical Methods
PublikacjaHigh precision and fast measurement of gas concentrations is important for both understanding and monitoring various phenomena, from industrial and environmental to medical and scientific applications. This article deals with the recent progress in ammonia detection using in-situ solid-state and optical methods. Due to the continuous progress in material engineering and optoelectronic technologies, these methods are among the most...
-
Histaminol and Its Complexes with Copper(II) - Studies in Solid State and Solution
PublikacjaHistaminol [4(5)-(B-hydroxyethyl)imidazole, 4-(1H-imidazol-2-yl)ethanol, L] is an analogue of histamine and its minor metabolite. So far its properties have not been studied in detail due to the synthetic difficulties. Here, the structure and acid-base properties of histaminol, as well as the results of studies on its copper(II) complexes in solid state and aqueous solution are reported. Stability constants of the histaminol–CuII...
-
Detection of some volatile degradation products released during photoexposition of ranitidine in a solid state
PublikacjaRanitidine (RAN) is on top of the list of prescribed drugs, due to its popularity as a selective H2-receptor antagonist, which efficiently decreases the amount of acid produced in the stomach. RAN is not stable both in a solid state and in a solution, which creates manufacturing problems, requires appropriate storage conditions, and results in a short drug shelf-life. The aim of this work was to study the emission of volatile...
-
Phase separation in poly(butylene terephthalate)-based materials prepared by solid-state modification
PublikacjaThe morphology of a series of poly(butylene terephthalate) (PBT)/fatty acid dimer diol (FADD)-based copolyesters prepared by solid-state modi fi cation (SSM) was studied. It was shown that in copolyesters containing less than 10 wt% FADD two different phases, i.e. a PBT crystalline phase and a PBT-rich amorphous phase, are present. The FADD residues were more or less homogeneously distributed throughout the interlamellar regions....
-
Investigation of sour substances by a set of all-solid-state membrane electrodes
PublikacjaTestowano elektrody typu all solid state (ASS) w roztworach elektrolitów zawierających substancje o smaku kwaśnym. Elektrody typu ASS zawierają dwa typy membran. Badano wpływ grubości membrany oraz stosunku związek lipofilowy/ chlorek poliwinilu na odpowiedzi elektrod. Stwierdzono, że grubość elektro aktywnego polimeru, nie ma wpływu na czułość i stabilność elektrod w przeciwieństwie do grubości membrany składającej się ze związku...
-
New Architecture of Solid-State High-Voltage Pulse Generators
PublikacjaThe application of the nanosecond pulsed electric field (nsPEF) for biomedical treatments has gained more interest in recent decades due to the development of pulsed power technologies which provides the ability to control the electric field dose applied during tests. In this context, the proposed paper describes a new architecture of solid-state high-voltage pulse generators (SSHVPG) designed to generate fully customised sequences...
-
Morphology and local chain structure of polyamide 6 modified in the solid state with a semi-aromatic nylon salt
PublikacjaStructural and conformational differences between the polyamide 6 (PA6) homopolymer and two copolymers of PA6 modified in the solid state with 20 and 30 wt% of the semi-aromatic nylon salt of 1,5-diamino-2-methylpentane (Dytek A) and isophthalic acid (IPA) in the feed were investigated. Room temperature wide-angle X-ray diffraction (WAXD) analysis together with 13C{1H} cross-polarization/magic-angle spinning solid-state (CP/MAS)...
-
PU Polymers, Their Composites, and Nanocomposites: State of the Art and New Challenges
PublikacjaThe chapter is a review of the polyurethane(PU)-based composites and nanocomposites. The chapter details different components in the manufacturing of PU polymers, composites, and nanocomposites. The different types of glycols, isocyanates, and catalysts that are used for the synthesis of different polyurethanes are discussed. The applications and specialties of polyurethane composites and nanocomposites are also elaborated on.
-
Solid-state electrochemical gas sensors
PublikacjaW pracy przedstawiono budowę i zasadę działania wybranych typów elektrochemicznych czujników gazów zbudowanych na bazie elektrolitów stałych.
-
Synthesis, structural characterization and reactivity of new trisubstituted N1-acylamidrazones: solid state and solution studies
PublikacjaA series of new linear trisubstituted N1-acylamidrazones have been investigated using a variety of analytical techniques and theoretical calculations to check the influence of the type of N1-acyl substituent on the resonance forms and conformational behavior in the solid state and in solution. The 1D- and 2D-NMR experiments, supported by computational studies, revealed that in solution all amidrazones exhibit conformational syn/anti...
-
Thermodynamic Characteristics of Phenacetin in Solid State and Saturated Solutions in Several Neat and Binary Solvents
PublikacjaThe thermodynamic properties of phenacetin in solid state and in saturated conditions in neat and binary solvents were characterized based on differential scanning calorimetry and spectroscopic solubility measurements. The temperature-related heat capacity values measured for both the solid and melt states were provided and used for precise determination of the values for ideal solubility, fusion thermodynamic functions, and...
-
Assessing ecotoxicity, synergic and antagonistic actions of commonly used components of polymerization mixture in molecularly imprinted polymers preparation process
PublikacjaIncreasingly, the challenge is the optimal process of developing a suitable MIP-type sorptive material (taking into account its final form and application area), which is mainly related to the efficiency/effectiveness of the polymerization process. The lack of reaction or its low efficiency generates additional waste and puts it into the environmental cycle. The main aim of the performed research was the estimation of ecotoxicity,...
-
INVESTIGATION OF ACIDIC SOLUTIONS BY POTENTIOMETRIC TASTE SENSOR WITH ALL SOLID STATE ELECTRODES
PublikacjaPotentiometric 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...
-
All solid state electrodes taste sensor with modified polymer membranes for discrimination of mineral water with different CO2 content
PublikacjaA potentiometric taste sensor with All Solid State Electrodes containing five all solid state electrodes with appropriate lipophilic compounds (benzyldimethyltetradecylammonium chloride, dodecyltrimethylammonium bromide, palmitic acid, stearic acid, and phytol) embedded in a polymer membrane was applied for discrimination of mineral water samples differed in CO2 content. Samples of still, slightly sparkling, and sparkling Naleczowianka...
-
Structure and hyperfine interactions in Bi1−xNdxFeO3 solid solutions prepared by solid-state sintering
PublikacjaThe series of polycrystalline ceramic powders, Bi1xNdxFeO3 (x = 0.11) was successfully synthesized by mixed oxide method followed by pressureless sintering. X-ray diffraction and Mössbauer spectroscopy were used as complementary methods to study structure and hyperfine interactions of the samples. It was found that with an increase of Nd content, within the range of x = 0.20.3 a structural phase transition from rhombohedral to...
-
The possibility of the application of a potentiometric sensor with all-solid-state electrodes for the quality control of different natural waters
PublikacjaThe quality of various natural waters was examined by a new potentiometric sensor with six all solid state electrodes containing an appropriate lipophilic compound in a polymer membrane. Physicochemical parameters such as conductivity and acidity of tested waters were also tested. All waters were neutral or slightly alkaline and contained different ions (e.g., Cl–) due to the place of their sampling (a coastal zone and a moraine...
-
Solid phase microextraction: state of the art, opportunities and applications
PublikacjaSolid phase microextraction is one of the most popular green techniques used for sample preparations in analytical chemistry. It is a simple, rapid, sensitive, and solvent-free technique. Since SPME was first introduced in the early 1990s, there has been an intensification of research in order to elaborate new methodical solutions in many research facilities around the world, which could increase the use of this technique. More...