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Introducción y antecedentes El concepto de desarrollo sostenible surgió como idea principal tras la reunión de la comisión Brundtland en 1987. Esta reunión fue organizada por Naciones Unidas con el fin de tratar el deterioro del medio ambiente, originado por el desarrollo descontrolado de la humanidad. El desarrollo sostenible fue definido como un avance social y económico que asegure una vida sana y productiva al ser humano, pero que no comprometa las posibilidades de desarrollo de las generaciones venideras. Entre las conclusiones alcanzadas, se resaltó la necesitad de disponer de una mayor variedad de fuentes de energía. La filosofía de esta cumbre fue recogida en Agenda 21, un documento que pretendía servir como guía general de actuación para alcanzar un desarrollo sostenible a todos los niveles. Respecto a las ciencias, Agenda 21 subrayaba la necesidad de emplear todo el conocimiento científico en la consecución de los objetivos del desarrollo sostenible. En este sentido, la Environmental Protection Agency acuñó en 1998 un término, Green Chemistry, que reunía estas ideas y las aplicaba a la química a través de 12 principios que debían ser cumplidos en el camino hacia una química sostenible. Entre estos principios, el uso de fuentes renovables para la obtención de materias primas ha adquirido gran relevancia debido a las previsiones de agotamiento de una de las fuentes de energía y materias primas más importantes: el petróleo. Los aceites vegetales se incluyen entre estas fuentes renovables de materias primas, siendo actualmente una de las fuentes renovables más utilizadas por la industria química. Los aceites vegetales están básicamente compuestos por triglicéridos, que son moléculas formadas por glicerol y tres ácidos grasos. En general los ácidos grasos pueden ser completamente saturados o contener varios dobles enlaces que en algunos casos pueden encontrarse conjugados, pero también existen ácidos grasos que contienen grupos hidroxilo o epóxido. Cada aceite vegetal posee una distribución característica de ácidos grasos que determina sus propiedades físicas y químicas. En lo que respecta a la química de los polímeros, los aceites vegetales constituyen una atractiva materia prima debido a la amplia gama de transformaciones químicas que pueden llevarse a cabo para sintetizar monómeros de diversa naturaleza. La epoxidación de los dobles enlaces internos es la transformación más común, ya que permite, a través de la apertura del anillo oxiránico con diferentes reactivos, la introducción de una gran variedad de grupos funcionales. Los dobles enlaces internos pueden polimerizarse directamente en condiciones térmicas, con iniciadores de radicales o por polimerización catiónica. / Introducction The sustainable development concept came out of the United Nations Commision on Environment and Development in 1987 (Bruntland Commission) and it is defined as "the development that meets the needs of the present without compromising the ability of future generations to meet their own needs". From this point, both the society and the industry have considered what a sustainable development really means and the best ways to start to achieve it from their own standpoints. The principles of the United Nations Conference on environment and Development (UNCED) held in June 1992 in Rio de Janeiro, and Agenda 21, were formulated with the aim of preparing the world for the challenges of the 21st century. In this context, during the early 1990s the US Environmental Protection Agency (EPA) coined the phrase Green Chemistry "To promote innovative chemical technologies that reduce or eliminate the use of generation of hazardous substances in the design, manufacture and use of chemical products". The main challenges of Green Chemistry and Engineeiring can be summarized as: · utilizing renewable instead of scarce resources. · avoiding toxic/dangerous chemicals in safer processes to obtain safer products. · minimizing energy use. · minimizing waste and resource use, re-using products, recovering and recycling materials. So making processes globally more efficient. Plant oils are one of the most widely applied renewable raw materials in the chemical industry for non-fuel applications. Vegetable oils are triglycerides (tri-esters of glycerol with long-chain fatty acids) with varying composition of fatty acids depending on the plant they are extracted from. Depending on the composition of plant oils, their Chemicals and physical properties are different.Vegetable oils are very used in polymer chemistry. Triglycerides have different reactive points through which we can obtain polymers from plant oils.There are two main approaches:The first one is the chemical modification of the triglycerides obtaining a large number of polymerizable monomers like expoxides or alcohols. The second approach is the direct polymerization of the carbon-carbon doubles bonds of plant oils through a free radical or a cationic mechanism.The free radical polymerization of double bonds has received less attention than cationic mechanism which has been very studied by Larock's group.In both cases thermosetting polymers with comparable properties to those of industrial can be obtained. Because of increasing use of synthetic polymeric materials during the lasts decades and the large fraction of the fire load in homes, it is necessary the use of fire retardants to reduce combustibility of the polymers, and smoke or toxic fume production. To get these requirements, the development of effective flame retardant materials is a key factor. To reduce the flammability, flame retardants can act in the gas phase or in condensed phase. In the gas phase fire retardants act as scavengers of the highly reactive radical species that propagate the combustion. In the condensed-phase fire retardants interfere in the thermal degradation processes modifying the reaction pathways and promoting the formation of char instead of volatile degradation products. Finally some flame retardants can act in both phases. Objectives The main objective of this Thesis was to develop new fire retardant biobased thermosets from vegetable oils as renewable resources. To achieve this goal it was carried out the cationic copolymerization of soybean oil, styrene and divinylbenzene with different silicon-or boron-or phosphorus containing comonomers.

Les fibres naturelles telles que le coton et le lin sont utilisées depuis longtemps dans l'industrie textile. De plus, elles prennent de plus en plus d'importance dans l'industrie des composites comme substituants des fibres de verre, de carbone ou d'aramide. Cependant, les fibres naturelles doivent être modifiées pour surmonter certains inconvénients tels que l'inflammabilité, l'hydrophilie et l'oléophilie. Dans ce travail, les retardateurs de flamme (RF) phosphorés et fluoro-phosphorés sont greffés par bombardement électronique et par modification chimique sur des tissus de lin afin d’améliorer leur comportement au feu, l’hydrophobicité et l’oléophobie. L'effet de la composition chimique sur le greffage a été également évalué en utilisant des fibres de miscanthus comparativement aux tissus de lin. La réactivité de la double liaison C = C des monomères phosphorés est étudiée pour contrôler l’efficacité de greffage de différents RF. Les étapes du radiogreffage sont étudiées et contrôlées. L'efficacité de greffage a été évaluée par fluorescence X et analyse par rayons X à dispersion d'énergie (EDS) / microscopie électronique à balayage (SEM). La résonance magnétique nucléaire du proton est utilisée pour analyser l'effet de l'irradiation sur les différents monomères. Le comportement au feu des tissus modifiés est étudié en utilisant l’analyse thermogravimétrique, la microcalorimétrie de combustion, cône calorimètre et un test au feu préliminaire. Des tissus ignifuges et oléophobes ont été développés avec succès. / Many natural fibers have been used for a long time in textile industry as cotton and flax. Moreover, natural fibers are getting more importance in composites industry as a substitute for glass, carbon, or aramid fibers. However, they must be modified to overcome some disadvantages such as flammability, hydrophilicity and oleophilicity. In this work, phosphorus and fluoro-phosphorus flame retardants were grafted by e-beam radiation and chemical modification on flax fabrics to improve their flame retardancy, hydrophobicity and oleophobicity. The effect of chemical composition on grafting were also evaluated using miscanthus fibers in comparison to flax fabrics. The reactivity of the double bond C=C of the P-monomers was studied to control the grafting yield of various FRs. Radiation grafting steps were studied and controlled carefully. Grafting efficiency was assessed by X-ray fluorescence and Energy Dispersive X-Ray Analysis (EDX) / Scanning Electron Microscopy (SEM). Proton nuclear magnetic resonance was used to analyze the effect of irradiation on different monomers. Fire behavior of the modified fabrics was studied using thermogravimetric analysis, pyrolysis combustion flow calorimetry, cone calorimetry and a preliminary fire test. Flame retardant and oleophobic fabrics were successfully developed.

In the first part of this dissertation, glass fiber reinforced/unreinforced polyamide 6 (PA6) and polyamide 66 (PA66) were compounded with three different flame retardants, which were melamine cyanurate, red phosphorus and brominated epoxy with antimony trioxide, by using an industrial scale twin screw extruder. Then, to investigate flame retardancy of these specimens, UL-94, Limiting Oxygen Index (LOI) and Mass Loss Cone Calorimeter (MLC) tests were carried out. In addition to flammability tests, thermogravimetric analysis (TGA) and tensile testing were performed. Results of the tensile tests were evaluated by relating them with fiber length distributions and fracture surface morphologies under scanning electron microscope (SEM). Incorporation of melamine cyanurate (MCA) to PA6 led to some increase in LOI value and minor reductions in Peak Heat Release Rate (PHRR) value. However, it failed to improve UL-94 rating. Moreover, poor compatibility of MCA with PA6 matrix caused significant reductions in tensile strength. Brominated epoxy in combination with antimony trioxide (Br/Sb) was compounded with both glass fiber reinforced PA6 and PA66. Br/Sb synergism was found to impart excellent flammability reductions in LOI value and UL-94 as V-0 rating. Effectiveness of Br/Sb flame retardant was also proven by the MLC measurements, which showed excessive reductions in PHRR and Total Heat Evolved (THE) values. On the other hand, Br/Sb shifted the degradation temperature 100&deg / C lower and decreased the tensile strength value, due to poor fiber-matrix adhesion and decreased fiber lengths. Red phosphorus (RP), when introduced to glass fiber reinforced PA66 induced V-0 rating in UL-94 together with significant increase in LOI value, and major decrease in PHRR. Degradation temperature was 20&deg / C lower while mechanical properties were kept at acceptable values compared to neat glass fiber reinforced PA66. In the second part of this dissertation, to investigate synergistic flame retardancy of nanoclays / glass fiber reinforced PA6 was compounded by certain nanoclay and an organo-phosphorus flame retardant (OP), which contains aluminum phosphinate, melamine polyphosphate and zinc borate, in a laboratory scale twin screw extruder. Exfoliated clay structure of the nanocomposites was assessed by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM), while thermal stability and combustion behaviors were evaluated by TGA, LOI, UL-94 and MLC. Replacement of a certain fraction of the flame retardant with nanoclay was found to significantly reduce PHRR and THE values, and delay the ignition. Moreover, remarkable improvements were obtained in LOI values along with maintained UL-94 ratings. Residue characterization by ATR-FTIR and SEM ascribed the enhanced flame retardancy of nanocomposite specimens to the formation of a glassy boron-aluminum phosphate barrier reinforced by clay layers at the nanoscale.

The main objective of this study was to produce flame retardant polyamide-6 (PA-6) and polypropylene (PP) composites and fibers containing boron compounds. The synergistic effect on flame retardancy of boron compounds (boron silicon containing oligomer (BSi), zinc borate (ZnB), boron phosphate (BPO4), metal oxide doped BPO4 and lanthanum borate (LaB)) with conventional flame retardants were investigated. The synergistic effect of nano-clay with commercial flame retardants was also investigated in order to reduce the total amount of flame retardant that is essential for fiber applications. The UL-94, limiting oxygen index (LOI), differential scanning calorimeter (DSC), thermal gravimetric analysis (TGA), fourrier transform infrared spectroscopy (FTIR) and cone calorimeter tests were conducted on composite materials in order to investigate the effect of synergy agents on the flame retardant and thermal properties of conventional flame retardant containing PA-6 and PP composites. According to the results from composite materials, boron compounds and clay showed synergistic effect with phosphorus based commercial flame retardants by acting generally with a condensed phase mechanism by increasing the char formation and/or by increasing the barrier effect of the final char residue. Inspired from the previous studies, firstly, only nano-sized BPO4 containing flame retardant fibers were produced and characterized. In the view of the results obtained from the composite trials, the boron compounds and organo clay were used with phosphorus based flame retardants to produce flame retardant fibers. The characterization of fiber samples were made with mechanical testing, melt flow index measurements (MFI), TGA, DSC, SEM and Micro Combustion Calorimeter (MCC) tests. According to the results from fiber samples, the inclusion of BPO4 reduced the peak heat release rate of the pure PA-6 and PP fiber. The reduction for PA-6 is higher than the PP fiber due to char forming character of PA-6. The usage of boron compounds and clay with phosphorus based flame retardants caused further reduction of peak heat release rate (PHRR) and total heat release values and increased the char formation. The amount of reduction of PHRR and total heat release (THR) is not so much due to the thermally thin character of fiber samples of nearly 40 microns. It is evident that a fabric made with these fibers will show better flame retardant behavior than single fiber tests due to its thick character with respect to the fiber samples.

In this thesis there were two main purposes, the first one being to investigate effects of zinc borate (ZB) on the flammability behavior of ABS when used with and without a traditional brominated flame retardant (BFR) / antimony trioxide (AO) system. The second purpose was to investigate contribution of nanoclays (NC) to the flame retardancy performance of the same traditional BFR compound with various combinations of AO and ZB again in ABS matrix. For these purposes, materials were melt compounded by using a laboratory scale twin-screw extruder, while specimens were produced by injection or compression molding. Flame retardancy of the specimens were investigated by Mass Loss Cone Calorimeter (MLC), Limiting Oxygen Index (LOI) measurements and UL-94 vertical burning tests. Other characterization techniques required in this thesis were / X-ray diffraction analysis, scanning and transmission electron microscopy, thermogravimetric analysis and tensile tests. Studies for the first purpose indicated that almost all flame retardancy parameters were preserved when antimony trioxide were replaced with zinc borate as much as in the ratio of 1:3. Residue analyses revealed that predominant flame retardancy mechanism of traditional system was gas phase action, while zinc borate contributes especially in the condensed phase action by forming thicker and stronger char layer. Investigations for the second purpose basically concluded that use of nanoclays improved all flame retardancy parameters significantly. Residue analyses pointed out that nanoclays especially contribute to the formation of stronger and carbonaceoussilicate char acting as a barrier to heat and flammable gases and retarding volatilization via tortuous pathway. As an additional third purpose in this thesis, usability of three boron compounds (zinc borate ZB, boric acid BA, boron oxide BO) with two traditional flame retardants (organic phosphinate OP and melamine cyanurate MC) in neat PET and recycled PET were also examined leading to some promising results in MLC parameters.

This thesis is aimed to understand the role of nanofiller type, nanofiller dispersion, nanofiller geometry, and, presence of reinforcing fibers in flame retardancy of polymer nanocomposites. For this purpose, montmorillonite nanoclays, multi-walled carbon nanotubes, halloysite clay nanotubes and silica nanoparticles were used as nanofillers in polymeric matrices of poly (methyl methacrylate) (PMMA), high-impact polystyrene (HIPS), polylactide (PLA) and polyamide-6 (PA6) containing certain conventional flame retardant additives. Furthermore, the influence of nanofiller and flame retardant additives on fiber/matrix interfacial interactions was studied. Materials were prepared by twin-screw extrusion melt-mixing and ultrasound-assisted solution-mixing techniques. Characterization of nanocomposite morphology was done by X-ray diffraction and transmission electron microscopy. Flame retardancy was investigated by mass loss cone calorimetry, limiting oxygen index measurements and UL94 standard tests. Flame retardancy mechanisms were revealed by characterization of solid fire residues by scanning electron microscopy, transmission electron microscopy, infrared spectroscopy and X-ray diffraction. Thermal degradation and stability was studied using thermogravimetric analysis. Mechanical properties were determined by tension tests and fracture surfaces were observed under scanning electron microscope. Influence of nanofiller type was investigated comparing the behavior of montmorillonite nanoclay and multi-walled carbon nanotube reinforced PMMA nanocomposites containing phosphorous/nitrogenous intumescent flame retardant. Carbon nanotubes hindered the formation of intumescent inorganic phosphate barrier which caused the samples to be exposed to larger effective heat fluxes during combustion. Contrarily, nanoclays physically reinforced the protective barrier without disrupting the intumescent character, thereby allowing for lower heat release and mass loss rates, and increased amounts of residue upon combustion. Influence of nanofiller dispersion was studied comparing nanocomposite and microcomposite morphologies in montmorillonite nanoclay reinforced HIPS containing aluminum hydroxide flame retardant. Relative to microcomposite morphology, reductions in peak heat release rates were doubled along with higher limiting oxygen index and lower burning rates with nanocomposite formation. Improved flame retardancy was attributed to increased amounts of char residue and lower mass loss rates. Nanocomposite formation allowed for the recovery of tensile strength reductions caused by high loading level of the conventional flame retardant additive in polymer matrix. Influence of nanofiller geometry was investigated for phosphorus based intumescent flame-retarded PLA nanocomposites. Fire performance was increased in the order of rod-like (1-D) &lt / spherical (0-D) &lt / &lt / plate-like (2-D) geometries which matched qualitatively with the effective surface area of nanoparticles in the nanocomposite. Well-dispersed plate-like nanoparticles rapidly migrated and accumulated on exposed sample surface resulting in the formation of strong aluminum phosphate/montmorillonite nanocomposite residue. Mechanical properties were increased in the order of 0-D &lt / 1-D &lt / 2-D nanofillers corresponding to the order of their effective aspect ratios in the nanocomposite. Influence of fiber reinforcement was studied for montmorillonite nanoclay containing short-glass fiber-reinforced, phosphorus/nitrogen based flame-retarded PA6 composites. Substitution of a certain fraction of conventional additive with nanofiller significantly reduced peak heat release rate, delayed ignition and improved limiting oxygen index along with maintained UL94 ratings. Improved flame retardancy was ascribed to the formation of a nanostructured carbonaceous boron/aluminum phosphate barrier reinforced by well-dispersed montmorillonite nanolayers. Fiber/matrix interfacial interactions in flame-retarded PA6 and HIPS containing nanoclays were investigated using a micromechanical approach, and it was found that the influence of nanoclay on the interface depends on crystallinity of polymer matrix. While the fiber/matrix interfacial strength is reduced with nanoclay incorporation into amorphous matrix composites, significant interfacial strengthening was imparted by large surface area, well-dispersed clay nanolayers acting as heterogeneous nucleation sites for the semi-crystalline matrix.

In this thesis, there were four purposes. The first one was to investigate effects of nanoclays (NC) on the flammability behavior of polystyrene (PS). The second purpose was to investigate contribution of nanoclays to the flame retardancy performance of conventional phosphorus based flame retardant / triphenyl phosphate (TPP) and its synergist melamine cyanurate (MCA). For the third purpose contribution of nanoclays to the flame retardancy performance of another conventional halogenated flame retardant / brominated epoxy polymer (BE) and its synergist antimony trioxide (AO) was investigated. As the fourth purpose, effects of another nanoadditive / carbon nanotubes (CNTs) on the flammability behavior of PS with and without BE-AO flame retardant system was investigated. Materials were prepared via &ldquo / solution mixing&rdquo / method, while test specimens were shaped by compression and injection molding. Flammability behaviors were investigated by Mass Loss Cone Calorimeter (MLC), Limiting Oxygen Index (LOI) and UL-94 Vertical Burning tests. Other characterization techniques required in this thesis were / X-ray diffraction analyses, scanning and transmission electron microscopy, thermogravimetric analyses and tensile tests. It was revealed that use of nanoclays improved flame retardancy of PS significantly, mainly with &ldquo / condensed phase&rdquo / mechanism via formation of strong char barrier layers inhibiting mass and heat transfer. When nanoclays were used together with conventional flame retardant systems TPP-MCA and BE-AO, flame retardancy parameters improved further, this time due to the &ldquo / synergistic action&rdquo / of &ldquo / condensed phase mechanism&rdquo / of nanoclays and &ldquo / gas phase mechanism&rdquo / of the conventional systems. Use of carbon nanotubes also resulted in improvements in the flame retardancy of PS. However, &ldquo / condensed phase mechanism&rdquo / of CNTs were not as effective as the NCs, which might be due to the lower performance of 1D geometry (CNTs) compared to higher efficiency of 2D geometry (NC) in barrier formation. As an additional purpose, effects of mixing methods in the production of PS-Nanoclay composites were also investigated. It was seen that compared to &ldquo / solution mixing&rdquo / use of &ldquo / in-situ polymerization&rdquo / resulted in poorer flame retardancy parameters that might basically be due to residual monomers or oligomers left during polymerization.

Zinc borate is a flame retardant additive used in polymers, wood applications and textile products. There are different types of zinc borate having different chemical composition and structure. In this study, the production of zinc borate that had the molecular formula of 2ZnO.3B2O3.3,5H2O was studied. The aim of this study was to investigate the effects of reaction parameters on the properties of zinc borate that had been synthesized by the reaction of boric acid and zinc oxide at the existence of the seed crystals and to determine the optimum experimental conditions for zinc borate production reaction. Reaction kinetics was also investigated to find a suitable kinetics model. The effect of boric acid to zinc oxide ratio -H3BO3:ZnO ratio- (3:1, 3.5:1, 5:1 and 7:1), the particle size of zinc oxide (10&micro / m and 25&micro / m), stirring rate (275 rpm, 400 rpm, 800 rpm and 1600 rpm), temperature (75&deg / , 85&deg / and 95&deg / ) and size of seed crystals (10&micro / m and smaller size) on reaction rate, reaction completion time, composition and particle size distribution of zinc borate were investigated. Experiments were performed in a continuously stirring, temperature controlled batch reactor with a volume of 1.5L. During the experiments samples were taken to be analyzed in regular time intervals. The analyses of the samples gave the concentration change of zinc oxide and boron oxide in the solid as well as the conversion of zinc oxide to zinc borate with respect to time and the rate of reaction was calculated. The products were also analyzed for particle size distribution. The experimental results showed that the reaction rate increased with the increasing H3BO3:ZnO ratio, particle size of zinc oxide, stirring rate and temperature. The reaction completion time was also decreased by increasing H3BO3:ZnO ratio, stirring rate and temperature. The particle size of final product, zinc borate, decreased with increasing stirring rate and size of zinc borate used as seed and increased with increasing particle size of zinc oxide used as reactant. The average particle sizes of the final product zinc borates synthesized at the end of the experiments were ranged between 4.3 &micro / m and 16.6 &micro / m. The zinc borate production reaction was mainly fitted the unreacted core model for the case of diffusion through product layer controls.

Le polyméthacrylate de méthyle (PMMA) est un thermoplastique présentant de nombreux avantages (transparence, légèreté, flexibilité). Cependant, le caractère inflammable du PMMA est un frein pour son utilisation dans de nombreuses applications, connaissant les pertes humaines et matérielles causés par les incendies. Cette thèse avait donc pour but d'améliorer la stabilité thermique et le comportement au feu du PMMA. Dans un premier temps, nous avons étudié l'influence de la dispersion de kaolins purs et traités sur le comportement au feu et la dégradation thermique du PMMA. Nous nous sommes ensuite orientés vers la modification chimique du PMMA par la méthode de copolymérisation du méthacrylate de méthyle (MMA) avec deux co-monomères phosphonés. Enfin, nous nous sommes intéressés à l'incorporation chimique ou physique de deux types de particules de polyhedral oligomeric silsesquioxane (POSS) dans le PMMA ou dans le PMMA modifié (copolymère (MMA – co- monomère monophosphoné)). Cette dernière partie a permis de mettre évidence l'effet bénéfique de la combinaison des particules de POSS et du PMMA modifié sur la dégradation thermique et l'inflammabilité de PMMA. Dans nos travaux, une attention particulière a été portée sur l'effet de phosphore en phase gazeuse et en phase condensée. Dans ce contexte nous avons pu définir, pour le PMMA modifié par les co-monomères phosphonés, un indice d'efficacité du phosphore pour chaque phase. / Poly(methylmethacrylate) (PMMA) is an important thermoplastic, widely used in industry. Unfortunately, it is a highly flammable polymer. The aim of this research was to improve the thermal stability and fire behavior of PMMA. First, we studied the influence of the dispersion of pure or treated kaolin on the fire behavior and thermal stability of PMMA. In second part of this work, the chemical modification of PMMA, using copolymerization of methyl methacrylate (MMA) with two phosphonated co-monomers was studied. Finally, we interested in chemical or physical incorporation of two types of polyhedral oligomeric silsesquioxane particles (POSS) in the PMMA or modified PMMA copolymère (MMA – co- monophosphonated monomer)). The effect of the combination of POSS particles and modified PMMA on the thermal degradation and flammability of PMMA was studied. In our work, the effect of phosphorus in the gas and condensed phase was separately studied. This study allowed us to define an efficiency index of phosphorus in each phase.