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1
Content available remote Spalanie i rozkład termiczny żywicy epoksydowej z melaminą
PL
Spalanie i rozkład termiczny żywicy epoksydowej (EP) i żywicy epoksydowej z melaminą (EP/ME) zbadano za pomocą kalorymetru stożkowego i analizy termograwimetrycznej sprzężonej ze spektroskopią w podczerwieni z transformacją Fouriera (STA/FT-IR). Badanie wykazało, że zastosowanie melaminy w EP, jako środka ograniczającego palność, prowadziło do powstania warstwy zwęglonej na powierzchni spalanej próbki. W konsekwencji tego zmniejszała się maksymalna szybkość wydzielania ciepła oraz całkowita ilość wydzielanych dymów. Podczas analizy STA/FT-IR obserwowano wydzielanie się mniejszej ilości tlenku węgla dla EP/ME.
EN
The combustion and thermal decompn. of epoxy resin (EP) and epoxy resin with melamine (EP/ME) was studied using a cone calorimeter and thermogravimetric anal. coupled to FTIR (STA/FT-IR). The use of melamine in EP as a flame retardant resulted in the formation of a charred layer on the surface of the burned sample, which reduced the max. heat release rate and the total amt. of emitted fumes. During STA/FTIR anal., a lower amt. of CO release was observed for EP/ME.
EN
Purpose: The purpose of this investigation is to theoretical study of food contamination mechanisms by melamine and hazard of melamine for health. This purpose is justified as follows. A high percentage of nitrogen has caused the abuse of this chemical, because this amount of nitrogen brings about the properties of decomposition of protein molecules into this material, as a result of the increase in melamine in foods. The primary issues discussed are related to o introduce melamine and its sources to the potential of exposure to melamine and to address the risks of this hazardous material and enhance the safety of food products. Design/methodology/approach: The investigation was carried out using analytical analysis. Melamine accumulates in the body of humans and has different effects. The presence of melamine at a very low level is also dangerous for children, and the food safety incidents that occurred in 2008 were due to the presence of melamine in children's infant formula in China, has raised concerns about food security around the world. Findings: As a result analytical research we have this conclusion. Melamine is a chemical compound that is widely used in industry and especially in the production of packaging materials. Reducing the risk to human health can be achieved through the combined use of three factors: using proper control programs to prevent melamine from getting into food, preventing the migration of melamine in food and using no melamine detergents. Research limitations/implications: The investigation was carried out on the basis of open sources of information on the chemical properties of melamine, its presence in household and other materials and its ability to interact with organic media. Practical implications: The results of this study can be recommended to the Ministry of Health and the Ministry of Industry for the development of control programs to prevent melamine from getting into food. Originality/value: The main problem of food pollution by melamine is that this substance is contained in most packaging materials. And a study of the mechanisms the migration of melamine in food and a generalization of the results on the methods for determining melamine in food will help solve the problem of unhealthy food.
PL
Cel: Określenie wpływu dodatku melaminy i krzemionki w procesie dogarbowania na wybrane właściwości skór ze szczególnym uwzględnieniem palności. Artykuł przedstawia wyniki prac związanych z obróbką skór na etapie dogarbowania. W dogarbowaniu zastosowano różne ilości krzemionki i melaminy w celu uzyskania wyższej odporności skór na palność. Metody: W pracy wykonano badania eksperymentalne, które obejmowały dogarbowanie skór naturalnych oraz badania wybranych właściwości skór otrzymanych w wyniku tego procesu. Dogarbowanie wykonano w skali laboratoryjnej. Badania skór obejmowały parametry związane z komfortem użytkowania wyrobów skórzanych takich jak miękkość i przepuszczalność pary wodnej. W zakresie palności badania przeprowadzono za pomocą specjalnie opracowanych metod. Wykonano także badania odporności skór na palenie w warunkach ograniczonego dostępu tlenu. Ponadto określono odporność hydrotermiczną otrzymanych skór. Wyniki: Skład kompozycji dogarbowującej i rezultaty badań właściwości skóry posłużyły za bazę do optymalizacji oraz określenia wpływu dodatków melaminy i krzemionki na badane właściwości skóry. Rezultaty badań właściwości dogarbowanych skór wskazują na istnienie zależności między ilością dodatków w dogarbowaniu a palnością skóry. Wnioski: Na podstawie przeprowadzonych badań stwierdzono, że: 1. Wzrost ilości użytej melaminy i krzemionki w składzie kompozycji powoduje wzrost odporności próbek skóry na przepalenie, przy czym dominujący jest wpływ melaminy. 2. Dogarbowanie zarówno z dodatkami (krzemionka i melamina), jak i bez dodatków nieznacznie tylko obniża przepuszczalność pary wodnej dla wszystkich badanych wariantów. Dogarbowanie prowadzi do wzrostu temperatury skurczu o max. 4°C. 3. Wyniki optymalizacji wskazują, że kompromisowe optimum przy założonych właściwościach skóry utrzymuje się przy dodatku melaminy i krzemionki w kompozycji dogarbowującej na poziomie 0,06–0,5% dla krzemionki i 0,35–0,65% dla melaminy w warunkach przeprowadzonych badań.
EN
Aim: The purpose of the research was to determine the effect of the addition of melamine and silica in the retanning process on selected properties of leather with particular regard to flammability. The article presents the results of work related to the processing of leather at the retanning stage. Various amounts of silica and melamine were used in retanning in order to achieve a higher resistance of leather to flammability. Methods: The work involved experimental tests, which included retanning of natural leather and testing of selected properties of the leathers obtained. Retanning was carried out on a laboratory scale. The leather testing included parameters related to the comfort of using leather goods such as softness and water vapor permeability. Flammability tests of leather were carried out using specifically developed methods. The tests of flame resistance of leather under conditions of limited access of oxygen were also carried out. In addition, the hydrothermal resistance of the resulting hides was determined. Results: The composition of a retanning mixture and the results of the leather properties tests were the basis for the optimisation and determination of the effect of melamine and silica on the examined properties of leather. The results of investigations of the properties of retanned leather show a correlation between the amount of additives in retanning and on the flammability of the leather. Conclusions: Based on the conducted tests, it was found that: 1. The increase in the amount of melamine and silica used in the composition of the mixture increases the resistance of leather samples to burning through (with the influence of melamine being the more important of the two). 2. Retanning both with additives (silica and melamine) and without additives only slightly reduces the water vapour permeability for all tested variants. Retanning leads to an increase in the shrinkage temperature by max. 4°C. 3. The results of the optimisation show that the compromise optimum with the assumed properties of the leather is obtained with the addition of melamine and silica in the retanning mixture at 0.06–0.5% for silica and 0.35–0.65% for melamine under the test conditions.
4
Content available remote Evaluation of customer awareness of melamine dishware safety
EN
Daily use of the dishware may be associated with health risks in the event of incorrect use. The aim of the study was to analyse consumer behaviours on the market of melamine dishware and assess their knowledge relating to the potential health risks associated with using these products. The survey was conducted in the form of a questionnaire containing 16 single- and multiple choice questions. Study included 100 people. The results show that consumers are familiar with melamine dishware and are willing to use it, primarily because of its functionality and lightweight. Consumers are not interested in information placed on the label of melamine dishware and do not pay attention to the information on its safe use. Consumers have little knowledge relating to the potential risks associated with using melamine dishware, as well as its potential impact on the human health.
EN
A series of resins was synthesized and analyzed for selective ion-exchange nature for some metals. Substituted aniline was reacted with formaldehyde, melamine. For the synthesis of ion-exchange resins, sulfuric acid was used as a catalyst. These resins were characterized by elemental analysis and studied antimicrobial activities. Synthesized Resin shows ion exchange capability and moderate activity against microbial. Ion exchange resin also showed reusability and stability at an elevated temperature.
EN
Polyester / melamine based paints are widely used in coil coating. The curing time for this type of coatings on the production line is from 30 to 60 s. One of the essential components providing fast curing is an acid catalyst. The purpose of the present work was to study the effect of an acid catalyst amount on the cured coating performance. The investigation was carried out using saturated hydroxyfunctional polyester. Hexa methoxy methyl melamine (HMMM) was used as a curing agent. The weight ratio of polyester to HMMM was 85 : 15. As an acid catalyst p-toluene sulfonic acid (p-TSA) blocked with triethylamine was used. The p-TSA concentration in the formulations was from 0 to 1,1 % wt. A relationship between the acid catalyst concentration and certain coating properties, i.e. glass transition temperature, water resistance, MEK double-rub resistance, flexibility and gloss, was established. The coatings containing 0,3-0,7 % wt p-TSA were demonstrated to have the best performance properties.
PL
Znajomość oddziaływań pomiędzy polimerem a rozpuszczalnikami stosowanymi jako substancje testowe stanowi ważną informację o ich mieszalności oraz właściwościach termodynamicznych roztworów. Odwrócona chromatografia gazowa stanowi cenne narzędzie służące do badania właściwości termodynamicznych polimerów, pigmentów, wypełniaczy. Celem pracy było zbadanie wpływu procesu sieciowania żywic epoksydowych, ich liczby epoksydowej, metod sporządzania kolumn do badań oraz temperatury pomiaru na parametry wzajemnego oddziaływania Flory-Hugginsa żywic epoksydowych i określenie zmian parametrów rozpuszczalności usieciowanych i nieusieciowanych żywic.
EN
Knowledge of the interactions between the polymer and solvents used as test substances provides important information about their miscibility and the thermodynamic properties of solutions. Inverse gas chromatography is a valuable tool for the study of thermodynamic properties of polymers, pigments and fillers. In this study thermodynamic properties of epoxy resins were studied. The purpose was to examine the impact of cross-linking of epoxy resins, epoxy number of resins, method of column preparation and test temperatures on the Flory-Huggins interaction parameters of epoxy resins and the identification of changes in the solubility parameters of cross-linked and uncross-linked resins.
PL
W artykule zaprezentowano przegląd ważniejszych bezhalogenowych retardantów palenia tworzyw polimerowych. W zarysach omówiono sposób otrzymywania ortofosforanu, pirofosforanu i polifosforanu melaminy według technologii opracowanej w IChN Gliwice. Przedstawiono efekty działania fosforanów melaminy jako retardantów palenia w wybranych tworzywach polimerowych (PP, PE, PA6).
EN
The article reviews the most significant halogen free flame retardants applied in polymers. The production of ortophosphate, pyrophosphate and melamine polyphosphate in accordance with the technique developed at IChN Gliwice has been discussed. The effect of melamine polyphosphates as flame retardants in selected polymers (PP, PE, PA6) has been specified.
9
PL
Oligoeterole z pierścieniem 1,3,5-triazynowym i atomami boru otrzymywano w reakcjach N,N,N,N,N',N'-heksakis(2-hydroksyetylo)melaminy z kwasem borowym a następnie z węglanami alkilenowymi. Zbadano strukturę i właściwości fizyczne wytworzonych oligoeteroli. Uzyskane oligoeterole zastosowano do otrzymania pianek poliuretanowych o zwiększonej odporności termicznej i zmniejszonej palności. Właściwości tych pianek porównano z cechami pianek otrzymywanych bezpośrednio z melaminy i węglanów alkilenowych.
EN
Oligoetherols containing 1,3,5-triazine ring and boron atoms were synthesized in the reactions of N,N,N',N',N”,N”-hexakis(2-hydroxyethyl)melamine with boric acid, followed by reaction with alkylene carbonates. The structure and physical properties of the obtained oligoetherols were investigated. The oligoetherols were used for the preparation of polyurethane foams with improved thermal stability and reduced flammability. The properties of obtained foams were compared with those synthesized directly from melamine and alkylene carbonates.
EN
A novel liquid-phase microextraction (LPME) technique, based on a hollow fiber (HF), in conjunction with high-performance liquid chromatography, has been developed for analysis of melamine in milk products. Melamine was extracted directly from milk products by use of a hollow-fiber membrane filled with organic solvent. HFLPME conditions, for example pH, extraction solvent, temperature, stirring rate, and extraction time were optimized. The best extraction efficiency of melamine was achieved under the conditions: pH 9.5, 35 μL n -octanol as extraction solvent, temperature 55°C, stirring rate 300 rpm, and extraction time 30 min. The HF-LPME technique resulted in a preconcentration ratio of 29-fold. Baseline chromatographic separation of melamine was achieved on a C 18 column with 96:4 ( v / v ) 0.02 mol L -1 ammonium sulfate-methanol as isocratic mobile phase. The linearity of the method ranged from 1.0 to 100.0 μg mL -1, correlation coefficient 0.9994. The limit of detection by use of HF-LPME was 0.021 μg mL -1 at a signal-to-noise ratio of 3. The optimized HF-LPME technique was successfully applied to the analysis of melamine in milk products collected from different commodity manufacturing units.
11
Content available remote Synthesis and application of melamine urea based precondensates
EN
Formaldehyde based low molecular weight precondensates (fixers) are always have very important role in processing of woven fabrics. Two important applications of these chemicals are in fixing of dyes and improvement of crease resistant behavior of fabrics. The synthesis of a series of precondensates by the reaction of formaldehyde with various percent mole ratios of melamine/urea is described which belong to the class of thermosetting resins. The dyed cotton specimens were impregnated with fixers and cured at 150°C for 3 minutes using acetic acid curing catalyst. The rubbing fastness to crocking, color fastness to washing and light fastness is reported and found to be dependent on the fixing efficiency of precondensate to dye. Precondensate based on 50:50% mole ratio of melamine-urea-formaldehyde showed the excellent fixing efficacy. The fastness to light is found to be dependent on the aromatic character of melamine ring which obviously is due to the preferably absorption in the UV region. The fabrics with an intense color and good characteristics were obtained thus presenting a possibility for extension of the applied in practice textile precondensates.
EN
The characterization of carbonyl–metal and maleimidato–metal bonding has been performed using the topological analysis of electron distribution function estimated for molecules of ( 5-C5H5)M(CO)3( 1-N-maleimidato) (M = W, Mo) and ( 5-C5H5)Fe(CO)2( 1-N-maleimidato). The Atoms in Molecules (AIM) approach has been applied for characterization of and -components of the metal–ligand bonds. The -electron communication between trans-placed ligands is present in Wand Mo derivatives. The ellipticity parameter is suggested to be a useful and highly sensitive parameter in the analysis of the metal–ligand bonding
EN
Two novel proton transfer compounds LH2, (tataH2)(pydc), and L'H2, (tataH)2(pydc), (pydcH2 = 2,6-pyridinedicarboxylic acid and tata = melamine, 2,4,6-triamino-1,3,5-triazine), were synthesized and characterized by IR, 1Hand 13C NMRspectroscopy and solid state CPMAS 13C NMR. The (tataH2)2[Pb(pydc)2]2x2tata x4H2O complex (1) was prepared using L'H2and lead(II) nitrate, and characterized by IR andNMRspectroscopy and single crystal X-ray analysis. The PbII complex is a binuclear anionic complex [Pb(pydc)2] 2 4 , in which two metal fragments are linked via a central ten-membered PbN(13)C(18)C(22)O(24)Pb(A)N(13A)C(18A)C(22A)O(24A) ring. Extensive hydrogen bonding between carboxylate groups, (tataH2)2+ and water molecules throughout the PbII complex together with ion pairing play important roles in stabilizing the corresponding lattice. The protonation constants of the reactants, the equilibrium constants for the reaction of pydc with tata and the stoichiometry and stability of the PbII complex with L'H2 in aqueous solution were investigated by potentiometric pH titrations. The stoichiometry of one of themost abundant complexed species in solution was found to be the same as that of the crystalline lead complex.
14
Content available remote Reaktywne rozpuszczalniki melaminy z ketonów i formaldehydu
PL
W pracy przedstawiono wyniki badań nad otrzymywaniem reaktywnych rozpuszczalników z ketonów i formaldehydu w obecności trietyloaminy jako katalizatora. Jako ketony zastosowano: cykloheksanon, cyklopentanon, keton etylowo-metylowy, acetofenon, benzoiloaceton, biacetyl i acetyloaceton. W uzyskanych reaktywnych rozpuszczalnikach roztwarzano melaminę. Najwięcej melaminy roztworzono w reaktywnych rozpuszczalnikach otrzymanych w reakcjach 1 mola cykloheksanonu i ketonu etylowo-metylowego z 12 molami formaldehydu, przy 40% udziale wody. Roztwory melaminy w reaktywnych rozpuszczalnikach poddawano utwardzaniu termicznemu (w obecności katalizatorów kwaśnych), uzyskując lite tworzywa melaminowo-formaldehydowo-ketonowe, które charakteryzują się bardzo dobrą odpornością na wrzącą wodę. Zaproponowano możliwość wykorzystania tych roztworów do otrzymywania tworzyw napełnionych i spienionych. Tworzywa te, w porównaniu z klasycznymi, wykazują lepsze właściwości mechaniczne (tworzywa napełnione) lub zwiększoną odporność termiczną (tworzywa spienione).
EN
Reactive solvents of melamine were prepared by reacting ketones with an excess of formaldehyde in the presence of triethylamine catalyst. The ketones used were: cyclohexanone, cyclopentanone, acetophenone, acetylacetone, benzoylacetone, biacetyl or ethyl-methyl ketone. In the obtained reactive solvents the melamine was dissolved. The best solubility of melamine was observed for the solvent obtained by reacting 1 mole of cyclohexanone (or ethyl-methyl ketone) with 12 moles of formaldehyde (with 40 wt.-% of water). From these solutions of melamine in reactive solvents have been obtained melamine-formaldehyde-ketones plastics: water-resistant coat, filled plastics and expanded plastics (rigid and semirigid polyurethane foams). The new melamine-formaldehyde-ketone plastics obtained from the melamine solution in reactive solvents can be used as the materials of interesting applicated properties.
PL
Opracowano warunki syntezy polieteroli z pierścieniem s-triazynowym, badając szczegółowo reakcje melaminy z węglanem etylenu i węglanem propylenu. Przeprowadzono analizę chromatograficzną produktów ubocznych powstających w reakcjach melaminy z węglanami alkilenowymi i oznaczono je ilościowo. Na podstawie przeprowadzonych badań z zastosowaniem 1H-NMR, IR i MS (ESI) zaproponowano strukturę otrzymanych polieteroli. W reakcjach otrzymanych polieteroli z 4,4'-diizocyjanianem difenylometanu uzyskano spienione tworzywa poliuretanowe. Stwierdzono, że otrzymane pianki charakteryzują się bardzo dobrą odpornością termiczną. Przeprowadzono badania kinetyki reakcji melaminy z węglanami alkilenowymi. Zaproponowano mechanizm badanych reakcji. Zbadano wpływ temperatury na szybkość reakcji melaminy z węglanami alkilenowymi i wyznaczono parametry termodynamiczne tych reakcji (ɫG# , ɫH# , ɫS# ).
EN
The conditions of the synthesis of polyetherols with s-triazine ring have been developed while examining in detail reactions between melamine and ethylene carbonate or propylene carbonate. The chromatographic analysis of by-products coming from the reactions of melamine and alkylene carbonates has been carried out and the quantity of by-products has been determined. On the basis of the examinations by means of H-NMR, IR and MS (ESI) the structure of the received polyetherols has been proposed. In the reaction between the received polyetherols and diphenylmethyl-4,4'-diisocyanate polyurethane foams have been obtained. The obtained foams appear to have very good thermal resistance. The kinetics of reactions between melamine and alkylene carbonates has been examined. The mechanism of the examined reactions has been proposed. Temperature effect on the progress of the reactions between melamine and alkylene carbonates has been examined and thermodynamic variables have been determined (ɫG# , ɫH# , ɫS# ).
EN
The crystals of a new melaminium salt, i.e. melaminium butyrate were obtained by slow evaporation of an aqueous solution at room temperature. The room temperature powder infrared and R'aman measurements were carried out. DSC measurements clearly point to the occurrence of the phase transition of the first order at ca, 239 K. No detectable signal was observed during powder test for second harmonic generation.
18
Content available remote Analiza przebiegu reakcji melaminy z węglanem etylenu metodą ¹H-NMR
PL
W wyniku reakcji melaminy z nadmiarem węglanu etylenu otrzymuje się polieterole z pierścieniem s-triazynowym. W niniejszej pracy podjęto badania mające na celu analizę przebiegu procesu z wykorzystaniem spektroskopii ¹H-NMR na podstawie statystycznej zmiany zawartości grup reaktywnych melaminy w produktach otrzymywanych po reakcji melaminy z węglanem etylenu.
EN
In the reaction of melamine and excess of ethylene carbonate polyetherols with s-triazine ring have been obtained. In this paper results of an analysis of reaction by using ¹H-NMR technique and on the base of statistical change of containing of melamine's reactive groups are presented.
20
PL
W pracy przedstawiono wyniki badań dotyczących syntezy hydroksymetylowych pochodnych niektórych ketonów, tzw. reaktywnych rozpuszczalników melaminy. Strukturę reaktywnych rozpuszczalników otrzymywanych w reakcjach niektórych ketonów z formaldehydem potwierdzono, wykorzystując technikę 1H-NMR i IR. Badano również roztwarzanie melaminy i niektóre właściwości otrzymanych roztworów.
EN
Results of research concerning synthesis of reactive solvents of melamine are presented. The structure of reactive solvents obtained from some ketones and formaldehyde was estimated by 1H-NMR and IR spectrometry. Dissolution of melamine and properties of prepared solutions were investigated too.
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