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The work described in this thesis was concerned with the synthesis and attempted Ring Opening Metathesis Polymerisations (ROMP) of a series of monocyclic phospholenes and organophosphorus derivatives of bicyclo[2.2.1]heptene using a variety of catalysts and conditions. This thesis comprises five chapters. The first chapter deals with the background of fire retardancy, industrial water treatment and ROMP. Chapter two describes the synthesis and characterisation of some potential organophosphorus monomers. Chapter three gives details of the attempted ROMP of the potential monomers prepared in chapter two. Investigations into the possible preparation of oligomers using a variety of chain transfer agents are described in chapter four. The conclusions and proposals for future work are outlined in the final chapter.

The objective of the project was to develop halogen and phosphorous free flame retardant polyamide 66 composites using magnesium hydroxide, either alone or in admixtures. In common with alumina trihydrate (ATH), magnesium hydroxide has attracted considerable attention over the last twenty years, as a halogen and phosphorous free alternative for both thermoplastics and elastomers. However, owing to its greater thermal stability magnesium hydroxide can be added to thermoplastics (such as polyamide 66) which are melt processed at temperatures where alumina trihydrate is impractical due to premature degradation. There are problems however, using such a flame retardant system, due to the high filler loadings (~60 wt%) required to achieve adequate flame retardancy, which leads to detrimental effects on both processing and mechanical properties.

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.

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The major objectives of this research were to examine the bioaccumulation parameters [depuration rates (kd), half life (t1/2) and biomagnification factor (BMF)] of individual isomers of hexabromocyclododecane (HBCD, C12H18Br6) in fish and to test the hypothesis of in vivo bioisomerization. This was done by exposing three groups of juvenile rainbow trout (Oncorhynchus Mykiss) to food fortified with known concentrations of an individual diastereoisomer (α, β, γ) for 56 days (uptake phase) followed by 112 days (depuration phase) of unfortified food. A fourth group of fish were exposed to unfortified food for the duration of the experiment. Fish (n=4) from all four aquaria were sacrificed on days 0, 7, 14, 56, 63, 70, 112 and 168 and muscle tissue was extracted and analyzed for diastereoisomer concentrations by high performance liquid chromatography tandem mass spectrometry (LC/MS/MS). Bioaccumulation of the γ diastereoisomer was linear during the uptake phase while the α and β diastereoisomers were found to increase exponentially with respective doubling times of 14.1 and 20.5 days. Both the β and γ diastereoisomers followed first order depuration kinetics with calculated t1/2’s of 94 ± 25 and 84 ± 51 (± 1 × standard error) days, respectively. The BMF for the α diastereoisomer (BMF = 4.1) was one and a half times greater than the β-diastereoisomer (BMF = 2.6) and about one fifth larger than the γ-diastereoisomer (BMF = 3.6). The large BMF for the α diastereoisomer is consistent with this diastereoisomer dominating higher trophic level organisms in wildlife. Although the BMF of the β diastereoisomer suggests that it will biomagnify, because it is present in small quantities in commercial mixtures it is rarely detected in environmental samples. Results from these studies also provide evidence of bioisomerization of the β and γ diastereoisomers. Most importantly, the α diastereoisomer which was recalcitrant to bioisomerization by juvenile rainbow trout in this study and known to be the dominant diastereosiomer in fish, was bioformed from both the β and γ diastereoisomers. To our knowledge, this is the first report of bioisomerization of a halogenated organic pollutant in biota. / May 2006

A variety of materials were used to fabricate nanocoatings using layer-by-layer (LbL) assembly to reduce the flammability of cotton fabric. The most effective brominated flame retardants have raised concerns related to their toxicity and environmental impact, which has created a need for alternative flame retardant chemistries and approaches. Polymer nanocomposites typically exhibit reduced mass loss and heat release rates, along with anti-dripping behavior, all of which are believed to be due to the formation of a barrier surface layer. Despite these benefits, the viscosity and modulus of the final polymeric material is often altered, making industrial processing difficult. These challenges inspired the use of LbL assembly to create densely layered nanocomposites in an effort to produce more flame-retardant coatings. Laponite and montmorillonite (MMT) clay were paired with branched poly(ethylenimine) to create thin film assemblies that can be tailored by changing pH and concentration of aqueous deposition mixtures. Both films can be grown linearly as a function of layers deposited, and they contained at least 70 wt percent of clay. When applying these films to cotton fabric, the individual fibers are uniformly coated and the fabric has significant char left after burning. MMT-coated fabric exhibits reduced total heat release, suggesting a protective ceramic surface layer is created. Small molecule, POSS-based LbL thin films were also successfully deposited on cotton fabric. With less than 8 wt percent added to the total fabric weight, more than 12 wt percent char remained after microscale combustion calorimetry. Furthermore, afterglow time was reduced and the fabric weave structure and shape of the individual fibers were highly preserved following vertical flame testing. A silica-like sheath was formed after burning that protected the fibers. Finally, the first intumescent LbL assembly was deposited on cotton fabric. SEM images show significant bubble formation on fibers, coated with a 0.5 wt percent PAAm/1 wt percent PSP coating after burning. In several instances, a direct flame on the fabric was extinguished. The peak HRR and THR of coated fabric has 30 percent and 65 percent reduction, respectively, compared to the uncoated control fabric. These anti-flammable nanocoatings provide a relatively environmentally-friendly alternative for protecting fabrics, such as cotton, and lay the groundwork for rendering many other complex substrates (e.g., foam) flame-retardant without altering their processing and desirable mechanical behavior.

Los polímeros orgánicos, tanto naturales como sintéticos, son inherentemente combustibles y en presencia de una fuente de calor y de oxígeno se queman fácil y rápidamente. Aunque en los últimos años ha habido un incremento en el número de heteroelementos utilizados en compuestos retardantes a la llama, el mercado está todavía dominado por compuestos que contienen halógenos, especialmente cloro y bromo. Estos compuestos son excepcionalmente efectivos pero presentan el inconveniente que incrementan las cantidades de humos y productos de descomposición tóxicos y corrosivos que se desprenden durante la combustión del polímero. Como alternativa a estos, han surgido una nueva clase de resinas termoestables basadas químicamente en 3,4-dihidro-2H-1,3-benzoxazinas. Su síntesis es de gran simplicidad y se lleva a cabo por condensación de formaldehido con fenoles en presencia de aminas aromáticas en una relación molar determinada. Otra de las aproximaciones utilizadas recientemente ha sido el uso de compuestos organofosforados que han demostrado buena capacidad como retardantes a la llama para resinas epoxi a la vez que generan menos gases tóxicos y humos que los compuestos halogenados. El objetivo general de este trabajo ha consistido en el desarrollo de nuevos sistemas poliméricos termoestables resistentes al fuego, sin detrimento de las propiedades del material y no agresivos medioambientalmente. Se pretende mejorar las buenas propiedades de algunos materiales estándar actualmente empleados, resinas fenólicas y resinas epoxi, pero introduciendo la condición de no inflamabilidad mediante nuevos sistemas de ignifugación, basados en fósforo y nitrógeno, alternativos a los sistemas halogenados clásicos ampliamente utilizados en la actualidad, mucho más tóxicos y peligrosos para el medioambiente que los que se proponen como alternativa en este estudio. Para ello se ha llevado la síntesis y caracterización de sistemas entrecruzados basados en resina novolaca modificados en diferentes proporciones con anillos del tipo benzoxazina, utilizando un nuevo método de síntesis basado en el uso de 1,3,5-trifenilhexahidro-1,3,5-triazina. Se ha estudiado mediante calorimetría diferencial de barrido su comportamiento térmico así como la influencia que tienen los catalizadores en la temperatura de apertura de los anillos de benzoxazina. La estabilidad térmica de estos compuestos se ha estudiado mediante análisis termogravimétrico en atmósfera de nitrógeno y de aire. Estos sistemas presentan buena estabilidad térmica, aunque el tanto por ciento de modificación no parece influir en las propiedades térmicas de estos. Mediante análisis dinamomecánico se ha descrito que la modificación de resinas novolaca con anillos de benzoxazina permite obtener materiales con una buena integridad mecánica, pudiéndose establecer relaciones cualitativas de niveles de entrecruzamiento. La retardancia a la llama de estos materiales ha sido V-O y V-1 en función del grado de modificación según el test de inflamabilidad UL-94 V.En este trabajo también se han sintetizado compuestos epoxifosforilados para modificar los sistemas novolaca y novolaca-benzoxazina y estudiar sus propiedades térmicas, mecánicas e ignífugas. Estos glicidilos no contienen enlaces hidrolíticamente inestables y poseen óxido de fosfina en su estructura. Se ha sintetizado un nuevo monoglicidilfosfinato, el 10-óxido de 10-(2,3-epoxipropil)-9,10-dihidro-9-oxa-10-fosfafenantreno (DOPOGly) y un diglicidilo alifático que contiene óxido de fosfina en su estructura, el óxido de isobutilbis(glicidilpropiléter)fosfina (IHPOGly). El entrecruzamiento de resinas novolaca y novolaca-benzoxazina con DOPOGly y IHPOGly lleva a sistemas novolaca-epoxi y novolaca-benzoxazina-epoxi con distinto contenido de fósforo y diferente densidad de entrecruzamiento que no desprenden volátiles en la reacción de polimerización. Se ha podido ver mediante análisis termogravimétrico que la incorporación de enlaces C-P en estos sistemas disminuyen la estabilidad térmica de estos, a la vez que el contenido final de fósforo en los polímeros no influye en el resto carbonado a 800ºC en atmósfera inerte y si lo aumenta en atmósfera oxidante. Los sistemas novolaca-epoxifosforada presentan menor velocidad de degradación a grados de conversión elevados de acuerdo con la propuesta de formación de un residuo intumescente mientras que los sistemas novolaca-benzoxazina-epoxi presentan un mecanismo de descomposición complejo y no pueden relacionarse con la presencia de este. Al igual que en los sistemas novolaca-benzoxazina, se han podido establecer relaciones cualitativas de niveles de entrecruzamiento para los sistemas novolaca-benzoxazina-DOPOGly. Para los sistemas novolaca-IHPOGly y novolaca-benzoxazina-IHPOGly se han podido determinar la temperatura de transición vítrea que no había sido posible determinar por DSC y también las temperaturas de las transiciones secundarias que se han relacionado con la estructura química de los materiales. Finalmente, la adición de compuestos organofosforados a los sistemas novolaca y novolaca-benzoxazina de mayor grado de modificación, mejora su retardancia a la llama alcanzándose grados V-0 según el test UL-94 V. / Natural and synthetic organic polymers are inherently combustible and in presence of heat and oxygen source burn easy and quickly. Although in the last years there has been an increment in the number of heteroatoms used in flame retardant compounds, the market is still dominated especially by compounds that contain halogens, like chlorine and bromine. These compounds are exceptionally troops but they have the shortcommings as the increase in the quantities of smoke and toxic gases and corrosive decomposition products that come off during the polymer combustion. As alternative to these a new class of thermostable resins chemically based in 3,4-dyhidro-2H-1,3-benzoxazines has arisen. Its synthesis is of great simplicity and it is carried out by formaldehyde condensation with phenols in presence of aromatic amines in a fixed molar relationship. At the same time another of the approaches used recently has been the use of organophosphorated compounds that have demonstrated good capacity like flame retardants for epoxy resins because they generate less toxic gases and smoke that the halogenated compounds. The general objective of this work has been the development of new fire retardant thermosettings systems, keeping the material properties and environmentally friendly. The goals is to improve the good properties of some standard materials, phenolic and epoxy resins, but introducing the non inflammability character by means of new ignifugation systems, based on phosphorous and nitrogen, alternative to the classic halogenated systems widely used at the present time. The synthesis and characterization of novolac resin systems modified in different proportions with benzoxazine rings, using a new synthetic method based on the use of 1,3,5-triphenilhexahydro-1,3,5-triazine has been carried out. Their thermal behavior has been studied by differential scanning calorimetry as well as the influence that catalysts have in the ring opening reaction of benzoxazine rings. The thermal stability of these compounds has been studied using thermogravimetric analysis under nitrogen and air atmosphere. These systems show good thermal stability, and the chemical modification seem not to influence the thermal properties. Materials with good mechanical integrity have been obtained from the novolac-benzoxazine resins. Dynamomechanical analysis allowed us to establish qualitative relationships of crosslinking density and modification degree. V-O and V-1 were obtained when the materials were tested to according to the UL-94 V flammability test.Moreover, in this work, two epoxyphosphorated compounds have also been synthesized to modify novolac and novolac-benzoxazine systems and to study its thermal, mechanical and fireproof properties: 10-(2,3-epoxypropyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPOGly), and an aliphatic diglycidilic compound that contains phosphine oxide moieties in its structure, isobutylbis(glycidylpropylether) phosphine oxide (IHPOGly). These glycidylic compounds do not contain hydrolytically unstable bonds and possess phosphine oxide moieties in their structure. Novolac and novolac-benzoxazine resins crosslinked with DOPOGly and IHPOGly lead to systems with different phosphorous content and different crosslinking density. By means of thermogravimetric analysis it has been shown that the incorporation of C-P bonds in these systems diminishes their thermal stability. Moreover the char yield at 800ºC increased with the phosphorous content under air atmosphere, while it do not undergo significative changes under nitrogen atmosphere. Novolac-epoxy phosphorated systems show lower degradation rate at high conversion degrees than the non-phosphorous systems according to the formation of an intumescent char. The novolac-benzoxazine-epoxy systems show a complex decomposition mechanism that cannot be related to the presence of phosphorous. Like in novolac-benzoxazine systems, for the novolac-benzoxazine-DOPOGly systems we have been able to establish qualitative relationships of crosslinking levels. For novolac-IHPOGly and novolac-benzoxazine-IHPOGly systems the glass transition temperature have been measured by DMA. Moreover secondary relaxations that have been observed and related to the chemical structure of the materials. Finally, the addition of organophosphorated compounds to novolac and novolac-benzoxazine systems improves its flame retardancy and degrees V-0 according to the UL-94 V test have been reached.