Improvement in Char Strength with an Open Cage Silsesquioxane Flame Retardant

Different characterization techniques were used to study the hydrolysis and condensation reaction kinetics of 3-methacryloxypropyltrimethoxysilane (MAPTMS) to obtain open cage silsesquioxane oligomers. The formation of hydrogen bonds, which condition the chemical structures of the resulting products, was identified. Improved thermal and fire resistant behavior of unsaturated polyester (UP) composites prepared with aluminium trihydroxide (ATH) and the synthesized oligomer were registered. Opened silsesquioxane structures also showed an improvement in the mechanical properties of the char formed after firin

Interaction of the chromium–iron black pigment with porcelanised stoneware

A study has been undertaken on the interaction between the (Fe,Cr)2O3 black pigment and an industrial porcelanised stoneware composition at its firing temperature. The results indicate that the glassy phase that forms during firing preferentially extracts Fe2O3 from the pigment and probably contributes some Al2O3 to it, enriching the pigment composition in Cr2O3, without changing pigment crystal structure. The pigment alteration process mainly affects porcelanised stoneware microstructure and, to a lesser extent, color

Desenvolvimento de vidrados cerâmicos com propriedades bactericidas e fungicidas

Nos últimos anos foram desenvolvidas técnicas que permitem a síntese de materiais que, ao menos em uma de suas dimensões, são de tamanho nanométrico (1 a 100 nm), apresentando assim propriedades e funções significativamente diferentes das observadas nos materiais tradicionais de tamanho micrométrico. Os nanomateriais têm uma ampla faixa de aplicações especiais, especialmente em eletrônica, ciência dos materiais, comunicações e sistemas biológicos. As análises econômicas indicam que o mercado de nanotecnologia movimentará entre 750 milhões e 2 bilhões de euros a partir de 2015. No entanto, no setor cerâmico ainda não se começou a trabalhar com nanomateriais, pois as potenciais vantagens destes materiais ainda não foram valoradas convenientemente. É o que ocorre com as propriedades antimicrobianas que determinados nanomateriais podem aportar aos revestimentos cerâmicos. A aparição desta nova geração de materiais pode permitir a obtenção de produtos cerâmicos com propriedades bactericidas e fungicidas, cujas superfícies sejam capazes de impedir e eliminar o crescimento de organismos patogênicos, mantendo deste modo as melhores condições de segurança e higiene ambiental. Com isto, o setor cerâmico pode desenvolver produtos inovadores, de maior qualidade e alto valor agregado, com objetivo de aumentar sua competitividade.Este trabalho foi realizado graças ao apoio do Conselho da Indústria, Comércio e Navegação da Generalitat Valenciana, através do IMPIVA (n° de expediente IMIDIC/2009/10) e do Fundo Europeu de Desenvolvimento Regional

Low-cost ceramic membranes: A research opportunity for industrial application

Obtaining low-cost ceramic membranes has attracted great interest in the scientific community in last years, as it allows to preserve the advantages of ceramic materials while significantly reduce their manufacturing costs. This type of membranes is mainly based on the use of raw materials and manufacturing processes typical of traditional ceramic materials, i.e silicate-based ceramics. This work exhaustively reviews the raw materials, ceramic compositions and variables of the manufacturing processes used in the development of these membranes, with special emphasis on their numerous potential industrial applications

Preparation of chamott es as raw material for low - cost ceramic membranes

Low cost ceramic membranes are usually prepared fro m a mixture of natural raw materials and some organic porogen agent, as starch . The fact that the porogen must be completely eliminated during firing, leaving an int erconnected porous structure, impose large firing times, increasing the final price. A s tudy about the synthesis of porous chamottes as an alternative to organic pore formers was conducted to reduce firing costs. Chamottes were obtained from mixtures of a c lay and starch. Different starches were used and the influence of the composition and processing variables were studied. The viability of the porous chamottes was demonstra ted.Supported by the Spanish Ministerio de Economía y C ompetitividad (Plan Nacional de I+D, ref. CTQ2012 37450 C02 02)

Estudio del efecto fotocrómico que presentan los vidriados opacificados por esfena

White glazes opacified by sphene, based on the system SiO2-CaO-TiO2, are an alternative to the glazes in which the opacifying phase is zircon. However, it has been observed that this type of glaze displays photochromism (reversible change of colour after exposure to a light source), involving the appearance of a yellowish shade after the glaze has been subjected to sunlight for several hours, which then disappears after a few days. This effect has led to limited use of this type of glaze. In this study, a method of quantifying the photochromic effect by means of a UV light source is established. The microstructural characterisation of glazes with a pronounced tendency to display a photochromic effect has allowed the possible causes of the photochromic effect to be determined. Finally, a series of tests have been conducted that show that the photochromic effect is related to the impurities present in the glaze, as well as to the type and quantity of crystalline phases contained in the glaz

Thermal Degradation Mechanism of a Thermostable Polyester Stabilized with an Open-Cage Oligomeric Silsesquioxane

A polyester composite was prepared through the polymerization of an unsaturated ester resin with styrene and an open-cage oligomeric silsesquioxane with methacrylate groups. The effect of the open-cage oligomeric silsesquioxane on the thermal stability of the thermostable polyester was studied using both thermogravimetric analysis and differential thermal analysis. The results showed that the methacryl oligomeric silsesquioxane improved the thermal stability of the polyester. The decomposition mechanism of the polyester/oligomer silsesquioxane composite was proposed by Fourier transform infrared spectroscopy (FTIR) analysis of the volatiles

Calcium carbonate thermal decomposition in white-body wall tile during firing. II. Influence of body thickness and calcite content

The thermal decomposition process of the calcium carbonate (calcite powder) contained in porous ceramic pieces, with the same composition as that used industrially to manufacture white-firing wall tile bodies, was studied using test disks with different thicknesses and calcite concentrations. The experiments were conducted in a CO2-free air atmosphere, and the results confirmed the validity of the kinetic model and the equation proposed in a previous paper to reproduce the experimental results in the studied range of operating conditions.The authors thank the Instituto de la Mediana y Pequeña Empresa de Valencia (IMPIVA) of the Generalitat Valenciana for its financial help. They are also grateful for the support of ERDF funds from the European Union. Project reference IMIDIC/2007/10

Evaluation of the Dustiness of Different Kaolin Samples

Several samples of kaolin with different mean particle size were prepared and tested using the continuous drop method, one of the reference test methods according to standard EN 15051:2006 “Workplace atmospheres – Measurement of the dustiness of bulk materials – Requirements and reference test methods.” On the other hand, with a view to relating the dustiness of the materials to their properties, particle size distribution, specific surface area, and Hausner ratio of these samples were determined. This article presents a characterization of these samples and an assessment of the influence of some material parameters on dustiness. The results show that dustiness may significantly be affected by mean particle size, specific surface area, and Hausner ratio. Moreover, it is highlighted that a detailed study of the influence of fine particles content on the dustiness was carried out. This information is deemed essential for establishing the most efficient preventive and/or corrective measures to reduce the generation of fugitive emissions of particulate matter during kaolin processing, both into the outside atmosphere (air pollution) and inside the facilities (occupational health)

Nanobased coatings with improved NIR reflecting properties for building envelope materials: Development and natural aging effect measurement

none11Gian Marco Revel; Milena Martarelli; Miguel Ángel Bengochea; Ana Gozalbo; Maria Josè Orts; Anna Gaki; Maria Gregou; Maria Taxiarchou; Alvise Bianchin; Marco EmilianiRevel, Gian Marco; Milena, Martarelli; Miguel Ángel, Bengochea; Ana, Gozalbo; Maria Josè, Orts; Anna, Gaki; Maria, Gregou; Maria, Taxiarchou; Alvise, Bianchin; Marco, Emiliani; Martarelli, Milen