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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development of organic and inorganic intumescent coatings and their use in barrier fabrics

Telford, Christopher Carl January 2002 (has links)
No description available.
2

A study of intumescent coatings

Deogon, Malkit Singh January 1989 (has links)
Intumescent coatings are used in the field of fire protection to prevent certain construction elements reaching the critical temperatures at which excessive damage would. occur, thus avoiding premature structural collapse. The studies presented in this thesis have been directed towards an understanding of intumeseent coatings and the process of intumescence. The kinetics and mechanism of intumeseence are discussed. The behaviour of the raw materials used in the preparation of intumeseent coatings, was studied at elevated temperatures using thermal analytical techniques, and new formulations were developed. These formulations were examined In the laboratory using various screening tests and were also subjected to a large scale hydrocarbon fire test alongside other commercially-avallable coatings. A simplified coating formulation with the minimum of ingredients required to produce good intumescent properties was developed. This formulation was subjected to various heat-radiation intensities using an ISO ignitablilty apparatus. The behaviour of the intumescence, process observed was explained by a simple theoretical model. The model of Buckmasterv Anderson and Nachman was used and several new results were derived. In particular a relationship was derived giving the time taken for the temperature at the inner surface of the coating to reach a given value. The durability of the newly-developed intumescent coatings, and methods of improving it, were also investigated.
3

LOW FLAMMABILITY FOAM-LIKE MATERIALS BASED ON EPOXY, TANNIC ACID, SODIUM MONTMORILLONITE CLAY

Lang, Xiaolong 12 June 2014 (has links)
No description available.
4

Estudo e desenvolvimento de grafite como agente anti-chama para PVC / Study and development of graphite as fire retardant agent for PVC.

Macedo, Nadia Guerra 02 August 2011 (has links)
O PVC é um dos principais polímeros termoplásticos da atualidade graças à sua grande versatilidade. Entretanto, uma de suas características é a baixa estabilidade térmica, sendo necessário o emprego de aditivos em sua estrutura. Uma das maiores preocupações mundiais é a segurança, sendo que muitos produtos levam proteção anti-chama em sua composição. Entre os vários agentes retardadores de chama a grafite aparece como um material promissor e pouco estudado. No presente trabalho foi estudada uma série de grafites com propriedades anti-chama oriundas de óxido de grafite \"flake\". O óxido de grafite foi submetido a vários tratamentos térmicos em atmosfera para a obtenção de grafites expandidas. O comportamento anti-chama dessas grafites foi testado adicionando-se 20% em peso no PVC. Membranas desses compósitos foram preparadas utilizando-se um \"doctor blade\". Os compósitos de grafites produzidas foram caracterizados por microscopia de varredura eletrônica e análise térmica. Isotermas de adsorção/dessorção de N2 também foram coletadas para determinação de área superficial específica e distribuição de poros. A grafite com melhores propriedades anti-chama foi aquela obtida em temperatura mais elevada, 900oC, ou seja, a grafite com mais elevada área superficial específica e com maior capacidade de produção de fuligem. / PVC is one of the most important thermoplastic polymers because of its versatility. However, like other polymers, for many technological uses, there is a need to enhance its thermal stability. Security is a global concern, so, the use of some fire retardants is required in polymer composites. Expanded graphite appears as a cleaner type of fire retardants, not well known yet. In the present work, expanded graphite obtained from the graphite oxide was studied. It were prepared PVC composite-membranes with 20 weight % of expanded graphite employing Doctor Blade. The samples were characterized by scanning electron microscope, thermogravimetric analysis and N2 adsorption/desorption isotherms were also collected for the determination of specific surface area and porous distribuition. The results show that the best fire retardant behaviour was achieved by the expanded graphite at 900oC, the graphite with the higher specific surface area and with the largest capacity of soot production.
5

Detection of Polybrominated Diphenyl Ethers in Ambient Air at a Wastewater Treatment Facility in Tampa, Florida

White, Brenda L. 01 January 2011 (has links)
The goal of this study was to quantify the ambient air concentrations of polybrominated diphenyl ethers (PBDEs) from three locations within the Howard Curren Wastewater Treatment Facility located in Tampa, Florida. PBDEs have been linked to endocrine disruption, cancer, developmental concerns in children, as well as other toxic effects; however their precise roles concerning these deleterious effects remains to be determined. The present study was motivated by these potential health concerns posed by inhalational exposure to PBDEs. Ambient air was monitored with a Tisch Environmental PUF high volume sampler for 48 hours with collection on three types of media-quarts filter, PUF (polyurethane foam) and XAD-2 resin. The samples were then analyzed with GC/MS (gas chromatography/mass spectrometry) for eight PBDEs that are routinely detected. The results showed elevated levels of PBDEs at the 2nd and 3rd sampling locations indicating a possible increased presence in the ambient air at the facility. Levels of PBDE 47 ranked highest amongst the detected congeners. PBDE 209 was not detected at any site. The present results indicate that PBDEs may lead to an inhalational exposure, thus future experimentation is needed to fully evaluate the health complications associated with inhalational exposure route to PBDEs.
6

Fytinsyra som flamskyddsmedel på bomull och polyester / Phytic acid as a fire retardant on cotton and polyester

Kjellin, Sara January 2018 (has links)
Idag finns det flera hundra flamskyddsmedel på marknaden där en del är hälso- och miljöfarliga. Fytinsyra är en naturlig produkt från växtriket som är miljövänlig och icke-toxisk. Fytinsyra består till stor del av fosfor vilket gör att potential finns för ett grönt flamskyddsmedel vilket ska undersökas. Lösningar på 3 och 10 mass% fytinsyra har gjorts där sedan kalciumkloridhexahydrat, natriumhydroxid eller ammoniak med ett molförhållandet på 5 eller 12 har tillsatts. Tygbitarna, av bomull och polyester, doppades i lösningarna och torkades i 6 dagar för att sedan analyseras med ett ugnstest, förbränningstest, TGA och DSC. Bästa kombinationen för bomull blev när natrium tillsattes med ett molförhållande på 12 till 1. Denna lösning gav bäst resultat i förbränningstesten samt ger mest massa kvar enligt TGA analysen. Lösningen är även basisk vilket är bra då sura lösningar bryter ner bomullstyget. För bedömning av bästa kombinationen för polyester ligger DSC och TGA analyserna till grund. I DSC är det svårt att avgöra vilken lösning som är optimalast då natriumlösningarna höjer temperaturen för smältpunkten mycket medan effekten minskar som behövs för att smältningen ska äga rum har halverats i förhållande till obehandlad polyester. Däremot har effektförbrukningen för smältningen ökat för kalciumlösningarna medan temperaturen endast höjts någon grad. Därmed är det svårt att säga den optimala lösningen för polyester. / Today there are several hundred flame retardants on the market where some are hazardous for the health and environment. Phytic acid is a natural product from the plant kingdom, which is environmentally friendly and non-toxic. Phytic acid consists largely of phosphorus, which means that there is potential for a green flame retardant which will be investigated in this report. Solutions of 3 and 10% by weight of phytic acid were made where calcium chloride hexahydrate, sodium hydroxide or ammonia having a molar ratio of 5 or 12 were added. The cotton and polyester fabric pieces were dipped in the solutions and dried for 6 days, then analyzed by use of an oven test, a combustion test, TGA and DSC tests. The best combination for cotton was when sodium was added at a molar ratio of 12 to 1. This solution yielded the best results in the combustion test, and left the most bulk in accordance with the TGA analysis. The solution is also basic, which is good as acidic solutions break down the cotton fabric. To assess the best combination for polyester, the DSC and TGA analyzes were used. In DSC it is difficult to determine which solution is optimal as the sodium solutions raises the temperature where melting occurs by a lot, but the power needed for melting is halved relative to untreated polyester. On the other hand, the calcium solutions have increased the power needed for melting, but the melting point was raised by only some degree. Thus it is difficult to say which the optimal solution for polyester is.
7

Estudo e desenvolvimento de grafite como agente anti-chama para PVC / Study and development of graphite as fire retardant agent for PVC.

Nadia Guerra Macedo 02 August 2011 (has links)
O PVC é um dos principais polímeros termoplásticos da atualidade graças à sua grande versatilidade. Entretanto, uma de suas características é a baixa estabilidade térmica, sendo necessário o emprego de aditivos em sua estrutura. Uma das maiores preocupações mundiais é a segurança, sendo que muitos produtos levam proteção anti-chama em sua composição. Entre os vários agentes retardadores de chama a grafite aparece como um material promissor e pouco estudado. No presente trabalho foi estudada uma série de grafites com propriedades anti-chama oriundas de óxido de grafite \"flake\". O óxido de grafite foi submetido a vários tratamentos térmicos em atmosfera para a obtenção de grafites expandidas. O comportamento anti-chama dessas grafites foi testado adicionando-se 20% em peso no PVC. Membranas desses compósitos foram preparadas utilizando-se um \"doctor blade\". Os compósitos de grafites produzidas foram caracterizados por microscopia de varredura eletrônica e análise térmica. Isotermas de adsorção/dessorção de N2 também foram coletadas para determinação de área superficial específica e distribuição de poros. A grafite com melhores propriedades anti-chama foi aquela obtida em temperatura mais elevada, 900oC, ou seja, a grafite com mais elevada área superficial específica e com maior capacidade de produção de fuligem. / PVC is one of the most important thermoplastic polymers because of its versatility. However, like other polymers, for many technological uses, there is a need to enhance its thermal stability. Security is a global concern, so, the use of some fire retardants is required in polymer composites. Expanded graphite appears as a cleaner type of fire retardants, not well known yet. In the present work, expanded graphite obtained from the graphite oxide was studied. It were prepared PVC composite-membranes with 20 weight % of expanded graphite employing Doctor Blade. The samples were characterized by scanning electron microscope, thermogravimetric analysis and N2 adsorption/desorption isotherms were also collected for the determination of specific surface area and porous distribuition. The results show that the best fire retardant behaviour was achieved by the expanded graphite at 900oC, the graphite with the higher specific surface area and with the largest capacity of soot production.
8

Reaction to fire performance of wood and other building products

Tsantaridis, Lazaros January 2003 (has links)
<p>The theme of this thesis is the reaction to fire performanceof wood and other building products, andparticularly thematerial fire properties time to ignition, rate of heat releaseand smoke production. These properties have been measured by asmall-scale fire test method, the Cone Calorimeter, andpresented for different types of building products.</p><p>Uncertainty analysis, included instrument and assumptionuncertainty, has been performed for the case that both O2 andCO2 are measured for calculation of the rate of heat release inthe Cone Calorimeter. The partial derivatives for theuncertainty analysis are given. The relative uncertainty forthe rate of heat release measurements in the Cone Calorimeteris between ±5% to ±10% for rate of heat releasevalues larger than about 50 kW/m2.</p><p>The time to ignition in the Cone Calorimeter is compatiblewith the time to ignition in the ISO Ignitability test, whichis the main test method for measuring time to ignition. Thetime to ignition is an increasing linear function of density.The rate of heat release in the Cone Calorimeter is dependentof material thickness and of use of retainer frame. Thematerial thickness gives the heat release curve duration andshape. Thin materials have short burning time and two maximumvalues. Thick materials have long burning time and when thematerial is thicker than about 35 mm no second maximum appears.When the retainer frame is used the actual exposed surface isreduced from 0.01 m2 to 0.0088 m2, the rate of heat release isreduced and the burning time is increased. A comparison ofresults with and without use of the retainer frame gives thenequal results when the exposed area is set to 0.0088 m2 in thecase of using the retainer frame.</p><p>The time to flashover in the full-scale room corner test waspredicted on the basis of Cone Calorimeter data at 50 kW/m2 bya power law of ignition time, the total heat release calculatedover 300 s after ignition and the density of the product. Therelation gives a simple relation to evaluate if a productreaches flashover in the room corner test.</p><p>The smoke production has also been measured in the ConeCalorimeter. The white light and the laser smoke measurementsystems have shown similar results. There is a correlationbetween Cone Calorimeter and room corner test smoke productionwhen the products are divided into groups: those that reachflashover in the room corner test in less than 10 min and thosethat have more than 10 min to flashover. Temperature profilesin wood have been measured in the Cone Calorimeter by a simpletechnique. The effect of fire protective gypsum plasterboardson the charring of wood frame members has been determined andcompared with fullscale furnace wall tests. The protectiveeffects of twenty different boards have been presented. ConeCalorimeter and furnace tests show similar charring of wooduntil the boards fall down in furnace tests. After that, thecharring of wood is higher in the furnace, because the wood isexposed directly to the fire.</p><p><b>Keywords:</b>building products, charring of wood, ConeCalorimeter, fire retardant treated wood, fire tests,ignitability, mass loss, rate of heat release, reaction tofire, smoke production, wood products</p>
9

Reaction to fire performance of wood and other building products

Tsantaridis, Lazaros January 2003 (has links)
The theme of this thesis is the reaction to fire performanceof wood and other building products, andparticularly thematerial fire properties time to ignition, rate of heat releaseand smoke production. These properties have been measured by asmall-scale fire test method, the Cone Calorimeter, andpresented for different types of building products. Uncertainty analysis, included instrument and assumptionuncertainty, has been performed for the case that both O2 andCO2 are measured for calculation of the rate of heat release inthe Cone Calorimeter. The partial derivatives for theuncertainty analysis are given. The relative uncertainty forthe rate of heat release measurements in the Cone Calorimeteris between ±5% to ±10% for rate of heat releasevalues larger than about 50 kW/m2. The time to ignition in the Cone Calorimeter is compatiblewith the time to ignition in the ISO Ignitability test, whichis the main test method for measuring time to ignition. Thetime to ignition is an increasing linear function of density.The rate of heat release in the Cone Calorimeter is dependentof material thickness and of use of retainer frame. Thematerial thickness gives the heat release curve duration andshape. Thin materials have short burning time and two maximumvalues. Thick materials have long burning time and when thematerial is thicker than about 35 mm no second maximum appears.When the retainer frame is used the actual exposed surface isreduced from 0.01 m2 to 0.0088 m2, the rate of heat release isreduced and the burning time is increased. A comparison ofresults with and without use of the retainer frame gives thenequal results when the exposed area is set to 0.0088 m2 in thecase of using the retainer frame. The time to flashover in the full-scale room corner test waspredicted on the basis of Cone Calorimeter data at 50 kW/m2 bya power law of ignition time, the total heat release calculatedover 300 s after ignition and the density of the product. Therelation gives a simple relation to evaluate if a productreaches flashover in the room corner test. The smoke production has also been measured in the ConeCalorimeter. The white light and the laser smoke measurementsystems have shown similar results. There is a correlationbetween Cone Calorimeter and room corner test smoke productionwhen the products are divided into groups: those that reachflashover in the room corner test in less than 10 min and thosethat have more than 10 min to flashover. Temperature profilesin wood have been measured in the Cone Calorimeter by a simpletechnique. The effect of fire protective gypsum plasterboardson the charring of wood frame members has been determined andcompared with fullscale furnace wall tests. The protectiveeffects of twenty different boards have been presented. ConeCalorimeter and furnace tests show similar charring of wooduntil the boards fall down in furnace tests. After that, thecharring of wood is higher in the furnace, because the wood isexposed directly to the fire. Keywords:building products, charring of wood, ConeCalorimeter, fire retardant treated wood, fire tests,ignitability, mass loss, rate of heat release, reaction tofire, smoke production, wood products / <p>NR 20140805</p>
10

BRANDSKYDDAT TRÄ : Jämförelse mellan obehandlat, brandskyddsmålat och brandskyddsimpregnerat trä

Neumann, Dorothea January 2015 (has links)
Environmental issues and the housing shortage is an ongoing debate among politicians. Wood is a building material that Sweden has plenty of and it is a material that, according to research, does not contribute to as much carbon dioxide emissions during production, compared to other construction materials such as concrete and steel. Therefore the demand for timber, in both facade claddings and external wall constructions, is increasing. In light of this, the purpose with this degree project is to study different fire protection methods for wood and compare it to untreated wood. Collecting the facts and information for this degree project at Mälardalens University, is done through literature studies, surveys, and two experiments conducted on two selected fire retardants. The experiments were conducted to test untreated, fire protection impregnated and wood with fire proof paint. One of the experiments tested the load-carrying capacity of the beams after being charred with a gas burner. The other experiment investigated the surface layer and measured the fire spread rate and both experiments tested the fire resistance. The experiments that were conducted concluded that out of the three different methods for facades and beams, fire protection impregnation was the best choice in all five chosen categories: load-carrying capacity, fire resistance, surfaces, environmental impact and health safety for workers. / Miljöfrågan och bostadsbristen är två pågående debatter bland politikerna. Ett byggmaterial som både är miljövänligt och lätt att bygga med är trä. Det är ett byggmaterial som Sverige har gott om och enligt forskning bidrar det inte med lika mycket koldioxidutsläpp vid produktionen jämfört med andra konstruktionsmaterial som betong och stål. Enligt äldre bygglagstiftningar var det enbart tillåtet att bygga hus med två våningar i trä. Det var godkänt att bygga hus med tre våningar om den nedersta våningen bestod utav sten och de två översta i trä. Den nya bygglagstiftningen har inga begränsningar på att använda trä i ytterväggar, oberoende av byggnadsklass så länge de uppfyller funktionskraven. Byggsektorn har varit medveten om att de fick bygga flervåningshus i trä men inte hur det skulle utföras och samtidigt uppfylla bygglagstiftningens krav. Resultatet av ändringarna i bygglagstiftningen, Boverkets byggregler, ökade efterfrågan och utbudet på brandskyddsmedel till trä. De vanligaste produkterna som finns ute för konsumenten är brandskyddsfärg och brandskyddsimpregnering. Trä kan genom brandskyddsimpregnering eller brandskyddsfärg få en brandteknisk klass enligt det europeiska systemet, EN 13501-1, upp mot B-s1,d0 som är högre än för obehandlat trä, Ds1, d0. Tekniskt sett går det att bygga Br1-byggnader med obehandlat trä, dock så krävs det ett antal åtgärder för att uppfylla Boverkets byggreglers funktionskrav, till exempel att installera automatiska släcksystem eller enbart ha trä på en begränsad del av fasaden. Med brandskyddsbehandling går det idag endast att uppnå brandteknisk ytskiktsklass B-s1,d0, vilket inte är tillräckligt enligt Boverkets byggregler som kräver lägst obrännbara fasadbeklädnader i ytskiktsklass A2-s1,d0 för att uppfylla allmänna råden. Fasadbeklädnader av trä, oavsett brandteknisk klass, kan testas med provmetoden SP FIRE 105 och därmed uppfylla föreskriftens krav på ytterväggskonstruktioner med avseende på brandspridning längs fasadytan. Syftet med arbetet är att jämföra olika brandskyddsmetoder av trä och undersöka vilken eller vilka som är bäst lämpad att använda i flervåningshus ur bland annat miljö-, arbetsmiljö- och brandsynpunkt. Detta uppnås genom en litteraturstudie som fokuserar på ämnet brandskyddsmetoder av trä och genom två försök genomfördes för att testa obehandlat, brandskyddsimpregnerat och brandskyddsmålat trä. Ett försök testade bärförmågan efter brandpåverkan, andra undersökte ytskikt, och båda försöken testade brandmotstånd. Bärförmågan testades genom att brandpåverkade reglar blev utsatta för en central punktlast i en Instron- maskin. Ytskikten prövades genom ett enklare försök baserad på testmetoden SP FIRE 105 på tre fasader. En obehandlad, en brandskyddsimpregnerad och en brandskyddsmålad. Mätningar och dokumentation gjordes med bland annat mätinstrument som plattermoelement och filmkamera. Båda typerna av brandskyddsmetoder kräver en kemisk framställning som varken är bra för naturen eller människan. Produktionen är automatiserad och därmed inte någon risk för någon människa. Den färdiga produkten är varken skadlig för miljön, människor eller djur, sålänge inte produkterna förtärs i större omfattning. Resultatet från undersökningen av de tre olika fasaderna visade att det brandskyddsimpregnerade virket klarade sig bäst i alla fem kategorier: bärförmåga, brandmotstånd, ytskikt, miljöpåverkan och arbetsmiljö. Slutsatsen är av det två typer av brandsskyddsmedel för trä som testades, är brandskyddsimpregnering den mest lönsammaste alla fem kategorier. Produkten är lätthanterad, avger inga farliga gaser och är i snitt inte dyrare än det obehandlade materialet. Dock är det viktigt att tänka på brandskyddsarbete och inte släppa på säkerheten för att konstruktionen byggs med brandskyddsimpregnerat trä.

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