In this research hyperbranched resins containing fatty acid residues like alkyds were synthesized. Dipentaerythritol which has six hydroxyl groups was used as the core molecule, and it was transesterified with (i) castor oil, and (ii) a mixture of castor oil and linseed oil at 240&deg / C in the presence of sodium hydroxide as catalyst. The resulting molecule, in either case, was then esterified with dimethylol propionic acid at 140&deg / C in the presence of p-toluene sulfonic acid as catalyst. Melamine-formaldehyde resin was synthesized to be used with the synthesized hyperbranched resins, and it was successfully modified by all hyperbranched resins at a ratio of 3:1. FTIR spectroscopy was used to characterize the hyperbranched resins and the thermal properties were determined by DSC. DSC showed that the hyperbranched resins decomposed between 315-345&deg / C. The viscosity of the resin that was synthesized by using only castor oil was 3.0 Pa.s and by using 50% linseed oil it was 1.0 Pa.s. When reacted with dimethylol propionic acid, the former&rsquo / s viscosity increased to 7.0 Pa.s, and the second&rsquo / s viscosity increased to 3.7 Pa.s. The hyperbranched resins showed excellent adhesion, gloss, flexibility, and formability. The mixture of hyperbranched resin plus melamine-formaldehyde resin samples had higher hardness values but lower gloss, adhesion and bending resistance values than the hyperbranched resins, and they had good impact and abrasion resistances.

Nesse trabalho obtiveram-se membranas de poli(imida) ramifricada com tamanho de poro ajustável usando melamina como agente de ramificação e indutor da formação de poros. Estas poli(imidas) foram sulfonadas usando-se ácido sulfúrico concentrado eficazmente. Finalmente, obtivemos membranas de carbono molecular por pirólise sob atmosfera inerte das poli(imidas) ramificadas. Estas membranas apresentam canais micrométricos paralelos à superfície e uma estrutura assimétrica constituída de uma camada densa filtrante e uma camada com canais micrométricos paralelos à superfície altamente ordenados. A membrana apresentou boa estabilidade química frente ao ataque por radicais hidroxila gerados via reação de Fenton. / In this work was obtained branched poly(imides) with tuned pore size using melamine as branching and pore induction agent. The poly(imides) with were efficiently sulfonated with concentrated sulfuric acid. Finally, the molecular sieve carbon membranes were obtained by pyrolysis under inert atmosphere of the branched poly(imides). These membranes have an asymmetric structure with a dense filtering layer and a porous layer with highly ordered channels standing parallel to the surface. These membranes display good chemical stability toward hydroxyl radical attack produced by Fenton reaction.

No description available.

No description available.

The regulations of many food products in the United States have been made and followed very well but unfortunately some products are not put under such rigorous standards as others. This leads to products being sold, that are thought to be healthy, but in reality contain unknown ingredients that may be hazardous to the consumers. With the use of several instrumentations and techniques the detection, characterization and identification of these unknown contaminates can be determined. Both the AZ-100 and the TE2000 inverted microscope were used for visual characterizations, image collection and to help guide the extraction. Direct analyte-probed nanoextraction (DAPNe) technique and nanospray ionization mass spectrometry (NSI-MS) was the technique used for examination and identification of all adulterants. A Raman imaging technique was than introduced and has proven to be a rapid, non-destructive and distinctive way to localize a specific adulterant. By compiling these techniques then applying them to the FDA supplied test samples three major adulterants were detected and identified.

Nuestro producto se dirige a parejas y/o personas en espera de un hijo a corto plazo. La demanda de estas familias por estar preparadas y optimizar el espacio destinado a sus hijos hace que busquen soluciones de muebles funcionales disponibles en el mercado. Basado en nuestro análisis del entorno, se desprende que en Lima Metropolitana contamos con un 42.60% de potenciales clientes en etapa de maternidad. De acuerdo a nuestra investigación de sectores socio-económicos, el nivel C posee el poder adquisitivo para adquirir el producto que ofrecemos. Adicionalmente, por medio de nuestro estudio de mercado basado en encuestas, decidimos orientarnos a Lima Metropolitana. Para poder conocer con mayor profundidad el perfil del segmento, fue necesario la realización de entrevistas a profundidad. Se identificó que una parte del mercado no maneja entre sus opciones iniciales un producto elaborado de melamina, por lo cual existe una oportunidad para aprovechar. En cuanto a nuestro desarrollo de plan de marketing tomaremos como punto de partida y referencia los precios de la competencia, ofreciendo modelos diferenciados y novedosos para crear un producto más atractivo. Sobre nuestra publicidad, será realizada de una forma agresiva por medio de redes sociales buscando convertirla en nuestro principal canal de atención y ventas. En nuestro plan económico se obtiene un VPN ascendente a S/ 532,349.00; lo cual nos indica que nuestro proyecto es viable. Tomando como base todo el estudio realizado, nuestro producto se perfila como rentable y con una alta oportunidad de consolidarse en el sector. / Our product is intended for couples or people that are going to have a kid in a short time. The demand of these families for being prepared and for optimizing the space for their children makes them look for functional furniture solutions on the market. According to to our environment analysis, it is known that in Metropolitan Lima we have 42.60% of potential clients in the maternity stage. In line with our investigation in socio-economic sectors, level C has the purchasing power to buy the product we offer. Additionally, through our market study based on evaluations, we decided to target Metropolitan Lima. In order to know the profile of the segment in a deeper way, it was necessary to do in-depth interviews which helped to identify that a part of the market does not consider among their initial options a product made from melamine, so there is an opportunity to take advantage of it. In relation to our development of marketing plan, we will take as a starting point and reference the competitor’s price, differentiated and innovative models to create a more attractive product. About our advertising, it will be performed in an aggressive way through social networks in order to make it our main service and sales channel. In our economic plan, a NPV (Net present value) of S/ 532,349.00; which indicates that our project is viable. Based on the complete study, our product is profitable and with a high opportunity to consolidate in the sector. / Trabajo de investigación

In this study southern pine scrim was treated with low molecular weight melamine formaldehyde (MF), phenolic formaldehyde (PF), and furfuryl alcohol (FA) at different loadings and formed into 25-mm thick panels. Mechanical, dimensional and biological properties were evaluated. Results showed that samples treated with 5 percent MF had the highest MOE, MOR and work to maximum load values (15.3 GPa, 54.2 MPa and 25.4 KJ/m3, respectively), while those treated with 10 percent MF had the highest internal bond and edgewise toughness values of 390 kPa and 12 N•m, respectively. With respect to dimensional stability, samples treated with 20 percent FA had the lowest swelling value (ASE = 36.8 percent), and the lowest water absorption value (27.5 percent). Dynamic swelling test revealed much higher ASE value (> 45 percent) for furfurylated samples. As for termite resistance, both untreated and treated samples had little weight loss (1.10-1.56 percent), high visual rating (8-9.3/10), and 100 percent mortality in laboratory test.

Melamine and cyanuric acid are widely used in industry and in scientific research. The mixture of melamine and cyanuric acid can form a hydrogen-bonded network structure which has been used as a surface template in supramolecular chemistry. In this work, the thermochemical properties of melamine and cyanuric acid were characterized using mass spectrometry measurements and computational studies. The proton affinity and the gas-phase acidity were determined with the application of the extended Cooks kinetic method. A triple-quadrupole mass spectrometer equipped with an electrospray source was employed for this study. For melamine, the proton affinity, the gas-phase basicity, and the protonation entropy were determined to be 226.2 ± 2.0 kcal/mol, 218.4 ± 2.0 kcal/mol and 26.2 ± 2.0 cal/mol K, respectively. For cyanuric acid, the deprotonation enthalpy, the gas-phase acidity, and the deprotonation entropy were determined to be 330.7 ± 2.0 kcal/mol, 322.9 ± 2.0 kcal/mol and 26.1 ± 2.0 cal/mol K, respectively. The geometries and energetics of melamine, cyanuric acid, and related molecules/ions were calculated at the B3LYP/6-31+G(d) level of theory. The theoretical proton affinity and deprotonation enthalpy were calculated using the corresponding isodesmic proton transfer reactions. The computationally predicted proton affinity of melamine (225.9 kcal/mol) and gas-phase deprotonation enthalpy of cyanuric acid (328.4 kcal/mol) were in good agreement with the experimental results. Melamine is best represented as the imide-like triazine-triamine form and the triazine nitrogen is more basic than the amino group nitrogen. Cyanuric acid is best represented as the keto-like tautomer and the N-H group is the most likely proton donor. Cyclohexane-based molecular switches have been of great interest in recent years. This work focused on the investigations of the thermochemical properties related to the switching process. A group of cyclohexane-based model compounds were selected for this study. The model compounds included trans -2-aminocyclohexanol, trans -4-aminocyclohexanol and trans -2-dimethylaminocyclohexanol. The proton affinities of the compounds were determined using the extended Cooks kinetic method. The values obtained were 238.5 ± 2.0 kcal/mol ( trans -2-dimethylaminocyclohexanol), 225.5 ± 2.0 kcal/mol ( trans -2-aminocyclohexanol) and 220.4 ± 2.0 kcal/mol ( trans -4-aminocyclohexanol). Various molecular structures related to the model compounds and the switching molecules were calculated at the B3LYP/6-31+G(d) level of theory. The theoretical proton affinities of all the molecules investigated were also calculated at the same level of theory using corresponding isodesmic reactions. The results show that the proton affinities decrease as the relative positions of amino and alcohol groups change from ortho to meta to para . The stronger proton affinity of the ortho isomer may be due to the efficient intramolecular hydrogen bonding in the protonated form. The proton affinity of trans -2-dimethylaminocyclohexanol is stronger than that of trans -2-aminocyclohexanol by about 13 kcal/mol. Substitution of hydrogen atoms by methyl groups at nitrogen promotes the intramolecular hydrogen bonding between the amino group and the hydroxyl group upon protonation. This, in turn, may enhance the proton affinity of methylated molecule. Computational studies also show interesting trends for stabilities and proton affinities of the different structures. These data may be useful as a guide for designing efficient conformational switches.

Sammanfattning på svenska: Billacker är exponerade för solljus och nederbörd under hela lackens livslängd. Lacker behöver motstå faktorer i omgivningen som påverkar nedbrytningen för att leva upp till högt ställda visuella krav.  Metoder för att bromsa nedbrytningsprocesser kan utvecklas med hjälp av analys av nedbrytningen av lackerna. Målet med detta arbete är att utvärdera möjliga analysmetoder och experimentella tillvägagångssätt för att analysera kemiska nedbrytningsprocesser i akrylat-melamin- och akrylat-isocyanatsystem.  Akrylat-melamin- och akrylat-isocyanatsystem har i denna uppsats studerats med olika analysmetoder. Resultaten visar att FTIR (Fourier Transform Infrared) spektroskopi med dämpad totalreflektion (FTIR-ATR) detekterar kemiska förändringar tidigare än andra metoder, såsom glansmätningar, kulörmätningar och ljusoptiskt mikroskop.  Tecken på hydrolys och fotooxidation observerades med FTIR-ATR i ett tidigt skede av accelererad provning. Två beräkningssätt, fotooxidationsindex (POI) och melaminförlust, visade på kemiska förändringar i lackerna. Billacker med röd kulör uppvisade de allvarligaste tecknen på nedbrytning. / Automotive coatings are exposed to sunlight and rain during the entire service life. Coatings need to withstand degradation factors in the environment in order to maintain high visual demands.  Methods to delay the degradation processes can be developed through the analysis of the degradation of the coatings. The purpose of this thesis is to evaluate possible analytical methods and experimental procedures to analyze chemical degradation processes in acrylate-melamine and acrylate-isocyanate systems.  Acrylate-melamine and acrylate-isocyanate systems have been studied with different analytical methods in this work. The results show that Fourier Transform Infrared Spectroscopy with attenuated total reflection (FTIR-ATR) detects chemical changes in the coatings earlier than other methods, such as gloss measurements, colour measurements and Light-Optical Microscope.  Signs of hydrolysis and photooxidation were observed with FTIR-ATR in an early stage of accelerated testing. Two calculations, photo-oxidation index (POI) and melamine loss indicated chemical changes in the coatings. Automotive coatings of red colours showed the most severe signs of degradation.

Thesis (MScAgric (Animal Sciences))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The aim of this study was to determine the rate of transfer of melamine as fertilizer ingredient to kikuyu pastures and if melamine would be transferred from the fertilized pasture to cow’s milk. Three trials were conducted in the study, viz. a pilot pot plant trial, an applied pasture trial and a milk production trial. Melamine is a commercially available industrial chemical with a high nitrogen content. Large quantities of melamine waste can sometimes be incorporated into crop and pasture fertilizers due to the high N content. An initial pot plant trial with kikuyu was conducted to determine whether melamine would be absorbed as such from the soil to the plant material. The pots were fertilized in the form of melamine adulterated Chinese maize Gluten 60, at a rate equivalent to 8.8 kg of melamine/ha. Results indicated that melamine was indeed absorbed and 7 days after fertilization, the concentration of melamine in the grass was 228 mg/kg. An applied pasture trial was then conducted were three pastures of 0.3 ha each were used. One pasture served as a control and received N fertilization in the form of LAN at a rate of 40 kg N/ha. The other two pastures also received LAN, but with 10% (Treatment 1) and 20% (Treatment 2) of the LAN-N substituted with melamine-N. All three pastures also received P-fertilization in the form of Single Superphosphate at a rate of 20 kg P/ha and KCl fertilizer at a rate of 50 kg K/ha. Pasture samples were taken once a week for 10 weeks, each time at the exact same spot in each camp. Samples were dried and finely milled before analysis via LC-MS/MS for melamine content. The initial concentration of melamine in the grass of Treatment 2 was higher than that in the grass of Treatment 1. The rate at which melamine decayed in the plant material was found to be quite similar for the two melamine treatments. In this trial, melamine took around 10 weeks to reach undetectable levels in the grass. It was concluded that melamine was absorbed as such from the soil by pasture grass when included in a fertilizer. For the milk production study, eighteen lactating Holstein cows, 60 ± 5.1 (SE) DIM, with a daily milk production of 36.5 ± 2.0 (SE) kg/d and weighing 609 ± 12.8 (SE) kg, were stratified according to milk production and then randomly allocated to three groups of six cows. The groups were then randomly allocated to the three pastures used in the applied pasture trial. Cows were kept on the melamine fertilized pasture for 9 days, in which they were allowed to graze the pasture for approximately 10 hours each day. After the 9 day period, melamine was withdrawn by placing the cows on the control pasture that did not receive melamine contaminated fertilization for another 7 days. During these 16 days, milk was collected twice a day, viz. during the morning and afternoon milkings. Milk samples of each cow were sub-divided into two samples, one was preserved with potassium dichromate and analysed for milk composition and the other was frozen until analysed for melamine by LC-MS/MS. For the duration of the trial, melamine containing milk was destroyed in order to prevent it from contaminating milk collected from the rest of the herd. Results from the analysis for melamine confirmed that melamine was transferred from melamine fertilized pasture to milk. In this study, it took 6 days from melamine withdrawal for melamine to reach undetectable levels in the milk. It was also found that the melamine fertilized pasture did not have any significant effect on the average milk production and milk composition of the cows. The aim of the study was met and it was confirmed that melamine can be transferred from fertilizer to the soil, to the pasture and to the milk of cows grazing these pastures. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om die tempo van oordrag van melamien as bemestingstof na Kikuyu weiding te bepaal, asook om te bepaal of melamien oorgedra sal word vanaf die bemeste weiding na melk. Drie proewe is uitgevoer wat ‘n potplant loodsproef, ‘n toegepaste weidings proef en ‘n melkproduksie proef ingesluit het. Melamien is ʼn kommersieël-beskikbare industriële chemikalieë met ʼn hoë stikstof inhoud. Groot hoeveelhede van melamien-afval kan soms in kunsmis ingesluit word vir die bemesting van gewasse en weidings, weens die hoë stikstof inhoud van melamien. ʼn Potplant loodsproef met Kikuyu is uitgevoer om te bepaal of melamien vanaf die grond deur die plantmateriaal geabsorbeer word. Melamienbemesting is in die vorm van vervalste Chinese mieliegluten 60 toegedien teen ʼn hoeveelheid gelykstaande aan 8.8 kg melamien/ha. Die resultate van hierdie proef het getoon dat melamien wel deur die plantmateriaal geabsorbeer is en 7 dae nadat bemesting toegedien is, was die konsentrasie van melamien in die gras 228 of mg/kg. ʼn Toegepaste weidingstudie is uitgevoer waar drie kampe van 0.3 ha elk gebruik is. Een van die kampe het as ʼn kontrole gedien en het stikstof bemesting in die vorm van KAN teen 40 kg N/ha ontvang. Die ander twee kampe het KAN bemesting ontvang waar 10% (Behandeling 1) en 20% (Behandeling 2) van die KAN-N deur melamien-N vervang is. Al drie kampe het ook fosfaatbemesting in die vorm van Enkel Superfosfaat ontvang teen 20 kg P/ha, asook KCl kunsmis teen 50 kg K/ha. Weidingmonsters is eenmaal per week op dieselfde plek in elke kamp geneem vir 10 weke nadat bemesting toegedien is geneem. Monsters is gedroog en daarna fyngemaal voordat dit vir melamieninhoud geanaliseer is met behulp van LC-MS/MS. Die aanvanklike melamienkonsentrasie in die gras van Behandeling 2 was hoër as die in die gras van Behandeling 1. Die tempo waarteen die melamienkonsentrasie in die plant materiaal afgeneem het, was baie dieselfde vir Behandelings 1 en Behandeling 2. Dit het ongeveer 10 weke geneem voordat die melamien in die gras nie-waarneembare vlakke bereik het. Die gevolgtrekking is gemaak dat melamien wat in die vorm van kunsmis toegedien word, as sodanig uit die grond geabsorbeer word deur die gras. Vir die melkproduksiestudie is agtien lakterede Holsteinkoeie, 60 ± 5.1 (SE) dae in melk, met ‘n daaglikse melkproduksie van 36.5 ± 2.0 (SE) kg/dag en ‘n liggaamsmassa van 609 ± 12.8 (SE) kg, volgens hul melkproduksie gerangskik en ewekansig in drie groepe van ses koeie elk ingedeel. Die groepe is daarna ewekansig aan die drie kampe, wat in die toegepaste weidingstudie gebruik is toegedien. Die koeie is vir 9 dae op die melamienbemeste weidings gehou, waartydens hulle toegelaat is om vir ongeveer 10 ure elke dag te wei. Na die tydperk van 9 d, is die koeie vanaf die melamienbemeste weidings onttrek deur hulle op die kontroleweiding te plaas vir ʼn verdere 7 dae. Gedurende hierdie 16 dae is melkmonsters tweekeer per dag geneem, tydens die oggend- en die middagmelkings. Die melkmonsters van elke koei is vervolgens onderverdeel in twee monsters, waarvan een met kaliumdichromaat gepreserveer is vir die beplaing van melksamestelling, terwyl die ander een gevries is totdat dit later vir melamien inhoud ontleed is met behulp van LC-MS/MS. Melk van die koeie wat op die melamienweidings gewei het, is weggegooi om te voorkom dat melk van die res van die kudde gekontamineer kon word. Die resultate van die melamienanalises het getoon dat melamien oorgedra word vanaf die melamienbemeste weiding na die melk. Tydens hierdie studie het dit 6 dae geneem vandat koeie vanaf die melamienbemeste weidings onttrek is, totdat die melkmelamien nie-bepaalbare vlakke bereik het. Daar is bevind dat melamienbemeste weidings geen betekenisvolle uitwerking op die gemiddelde produksie en samestelling van die melk gehad het nie. Die doel van hierdie studie is bereik en daar is getoon dat melamien vanaf kunsmis na die grond, na die gras en na die melk oorgedra kan word wanneer koeie op weidings geplaas word wat melamienbemeste kunsmis ontvang het.