Benzoxazine Monomers and Polymers Based on 3,3′-Dichloro-4,4′-Diaminodiphenylmethane: Synthesis and Characterization

To reveal the effect of chlorine substituents in the ring of aromatic amine on the synthesis process of benzoxazine monomer and on its polymerization ability, as well as to develop a fire-resistant material, a previously unreported benzoxazine monomer based on 3,3′-dichloro-4,4′-diaminodiphenylmethane was obtained in toluene and mixture toluene/isopropanol. The resulting benzoxazine monomers were thermally cured for 2 h at 180 °C, 4 h at 200 °C, 2 h at 220 °C. A comparison between the rheological, thermal and fire-resistant properties of the benzoxazines based on 3,3′-dichloro-4,4′-diaminodiphenylmethane and, for reference, 4,4′-diaminodimethylmethane was made. The effect of the reaction medium on the structure of the oligomeric fraction and the overall yield of the main product were studied and the toluene/ethanol mixture was found to provide the best conditions; however, in contrast to most known diamine-based benzoxazines, synthesis in the pure toluene is also possible. The synthesized monomers can be used as thermo- and fire-resistant binders for polymer composite materials, as well as hardeners for epoxy resins. Chlorine-containing polybenzoxazines require more severe conditions for polymerization but have better fire resistance.

Three in one: sizing, grafting and fire retardant treatment for producing fire-resistant textile material

In the weaving industry, cotton yarn undergoes mandatory sizing to uniformly pass the threads through the mechanisms of weaving machines, reduce breakage and improve the weaving process. Sizing is only necessary for weaving, and then sizing substances are removed from the fabric. With a successful combination of the sizing process and special processing of fabrics, significant progress is achieved in the technology of manufacturing fire-resistant fabrics and a significant economic, environmental effect. The purpose of the study is the development of a fire-retardant composition based on collagen, a method of grafting collagen to cellulose at the stage of sizing cotton yarn and obtaining fire-resistant textile material. By grafting a sizing composition containing collagen, polyacrylamide, boric acid, urea and potassium persulfate to cellulose, a highly effective fire-resistant material was obtained. The introduction of collagen and polyacrylamide in the composition sticks together the fibers of the yarn, at the same time makes the cotton material non-flammable when exposed to direct fire, reduces the time of smoke and the coefficient of smoke formation, which made it possible to obtain fire-resistant textile material belonging to a high category. By combining the processes of sizing and fire retardant processing of the main and weft yarns using biodegradable collagen, the technological operations of the production of fire-resistant material are reduced, which contributes to the conservation of natural resources and the solution of an acute environmental problem.

Enhancement of physical, chemical, and mechanical properties of biocomposite for the fire resistant material application

This study deals with the enhancement of physical and mechanical properties of oil palm empty fruit bunch fibers (OPEFB) for new fire resistant material application. Two flame retardants (organic and inorganic) were applied to improve the fire resistant capability of the produced fibers. The fire resistant capability was tested according to the ASTM D6413-99 method. Mechanical properties were characterized using a universal testing machine and the differential scanning calorimetry (DSC) was performed to investigate their thermal behaviors. The surface morphology of the produced fibers was observed using scanning electron microscopy (SEM). This study found that the fire resistant capability of the fibers can be improved by the addition of flame retardants. Thermal properties of the treated fibers can be enhanced compared to the untreated fibers. Mechanical properties inspection revealed that increasing the flame retardant concentration (0.5 to 1 M) can improve their tensile strength but started to decrease at a higher concentration (3 M). In general, the present work successfully performed the enhancement of non-woven OPEFB properties for foreseeable fire resistant material applications.

Geopolymer foam as a passive fire protection

More than 200 firefighters and 40 fire engines were involved in battling the blaze of Grenfell Tower in June 2017. Despite the heroic efforts of fire brigades the more than 80 people died. In the expert opinion the reason such size of the tragedy were the cladding - installed on in a recent renovation - has come under scrutiny, with experts saying a more fire-resistant type could have been used. The use of such type of cladding was probably price. The main motivation of research work is to develop cheap and fire resistant material for buildings and applications in civil engineering structures. The main aim of the research was development of foamed geopolymers based on fly ash and investigation their properties. The research methods used were: coefficient thermal conductivity test, fire-resistant test, visual analyses, density measurement and compressive strength test. The results show the foamed geopolymers has low coefficient thermal conductivity between 0.068 and 0.126 W/(m·K). They have excellent fire and heat resistant facilities, including resistance of this type of materials to the erosive action of fire. Moreover, they have reasonable mechanical properties - they were characterized by compressive strength between 0.5 and 3.5 MPa depending on the density, which ranged from 250 to 700 kg/m3. The conducted research confirmed that geopolymers have the highest fire resistance classes and can be used on a wide scale as a material for protection against various types of fire and as fire-resistant insulation materials in construction.

Fabrication of porous ceramics as clay/glass composite

<p>Nowadays porous ceramics are widely researched, becoming an increasingly marketable material in the world, mainly due to the wide possibilities of usage in different technical and technology industries. Porous ceramics are successfully used in the filtration and has a high potential of usage also in the production of heat insulation materials thus obtaining the material which combine high resistance that can compete with other heat insulation and constructive materials.</p><p class="R-AbstractKeywords">Article reports a study of porous ceramics, which are produced using foamglass pellets as melting fillers, despite the fact that these additives are not frequently used as filler in traditional ceramic materials. The basis of this method is mixing fire resistant material with hard and melting substance.</p><p class="R-AbstractKeywords">For the production of porous ceramics clay, hard filler, water and various sized foamglass pellets were used, thus allowing to determine optimal size of melting filler and thereby ensuring the necessary physical and mechanical properties of the obtained porous ceramic samples and required amount, size and division of pores. Compressive strength tests were performed, as well as density and water absorption of the samples was determined.</p><p class="R-AbstractKeywords">Obtained results of the study shows that ceramic materials, obtained within the research, have great potential of application for load-bearing constructions as constructive building materials, as well as insulation materials. Production of porous ceramics materials, where foamglass pellets are used as melting filler, allows to produce more effective ceramics, creating high added value for the final product. </p>

Study on Mineral Composition and Main Mineral Morphology of Bauxite from ZhongXiang, HuBei Province

In this paper, the mineral composition and main mineral morphology of bauxite were studied from ZhongXiang deposit, HuBei province. Through Electron Microscope Identification, there are two main rock types, oolitic, bean-like and aphanitic or fine crystalline structure of bauxite. The main mineral morphology is micro-crystalline or flake, crumby forms. The mineral and chemical compositions of samples were investigated by XRD, EPMA analysis tests. The EPMA results showed that Al2O3 content is 47.95% ~ 75.04%, in association with other isomorphous impurities, such as Si, Fe, Ti and Mg in varying proportions. The mineral compositions of bauxite ore are mainly aluminum, iron, silicon minerals, which totally account for from 83.01% to 86.40%. The XRD revealed that diaspore, hematite and kaolinite are the major mineral components in the bauxite ores. The bauxite from ZhongXiang deposits is a type of high diaspore bauxite, partly with clay minerals. Furthermore, the function of bauxite as a good fire-resistant material was discussed.

Influence of Features of Silicon Carbide Ceramic Matrix Composite (Cp/SiC) on Carbon Content

In this article, the properties of carbon particle modified silicon carbide (Cp/SiC) composites was studied. The mixture powder of nano carbon black and submicro-SiC was prepared through soft mechanochemical method. Then Cp/SiC composites was pressureless sintered.The result shows that appropriate content of carbon is 25 percent in this condition the machinability of Cp/SiC is better than that of SiC ceramic. At the same time, the oxidation resistence, wear resistence, and flexure strength of Cp/SiC meet the challenge for special fire resistant material.

Materials Considerations for Improved Flash/Flame Protection

To investigate the capabilities of protective clothing materials to withstand the initial radiant energy effects and secondary flame impingement from a blast and devise suggestions for new materials, better configuration designs, and manufacturability of those designs must be considered. This paper discusses results that will directly benefit soldiers and others with risk to exposure of flash/flames due to explosions. Dismounted soldiers need a material that has improved flash/flame protective qualities to better protect them in combat situations that may result in burn injuries from fires that originate from a blast. This paper investigates why the burns occurred, how the materials used in the current configuration of clothing could be improved upon, and what new materials choices can be made in other configurations to better protect dismounted soldiers. The causes of failure have been evaluated, and by way of reverse and forward engineering, alternative choice of materials and improved designs has been considered. As a result, a prototype can/will be built based on the design characteristics, tested, and potentially fielded for use by soldiers. The paper provides sufficient background information on the anatomy of explosions, physiology of burn injuries, and blast type and burn relationships. Current testing methods for testing burn-protection materials are discussed including both bench scales and full scale tests and the pros and cons of each. The engineering requirements for current fire resistant clothing are broken down. Then, a description of the assumptions is listed, and the engineering design process is applied to the problem to determine which characteristics are most important in this type of fire-resistant material. This process includes a survey and several design tools to narrow the design criteria to the most important engineering characteristics required for a successful application of the design. Another aspect is introduced by including an analysis of the heat transfer characteristics of fire-resistant materials to help narrow the criteria and better understand the problem.