The aim of this work was to produce environmentally safe flame-proofing compositions to give a wash-durable finish on textile and other substrates. Thus this work describes the preparation and application of new urea condensates formed from the reaction of urea with a variety of chemicals including phosphoric acid, phosphorous acid and sulphamic acid; the condensates gave different degrees of flame retardancy (FR) on a variety of substrates. Studies of urea thermal decomposition showed the production of isocyanic acid and ammonia, above "the urea melting point (l3S•C). Using an open reaction vessel, urea, sulphamic acid and phosphorous acid gave an exothermic reaction over the temperature range 120 - 140'C with gas liberation. The condensates thus formed contained aliphatic polyamide chains, containing urea groups and sulphur and phosphorus residues. According to the type and amount of initial materials, various urea condensates, capable of imparting different degrees of flame retardancy, were synthesized. The sulphamic acid/urea (SIU), phosphoric acid /urea (P AIU), sulphamic acid/phosphoric acid/urea (SJPAIU) and also sulphamic acid/phosphorous acid/urea (S/PH/U) condensates were produced. When these urea condensates were cooled down, Water-soluble products were produced, and these materials could be applied to the textile substrate using a pad-bake technique. Cotton fabrics were treated with these condensates: typically a pad-liquor contained 500 g/l of urea condensate, 10 g/I of wetting agent; fabric was padded to 80% wet pick-up, dried (80'C) and cured for two minutes (l65'C). These urea condensates, when cured on cotton at high temperature (16S'C), change to water-insoluble products; as a result of reactions between cellulose hydroxyl group and the urea condensate a complicated polymer structure network can be produced on the surface of a fabric and a flame retardant effect imparted. The SIU condensate only produced partial FR properties, while the rest of the compounds produced completely flame retardant fabrics. FT-IR analysis and NMR analysis was carried out on the urea condensates and also on the flame retardant fabrics. DSC thermal analysis was performed on the initial materials, urea condensates and also the treated fabrics. The characterization of urea condensate treated fabrics were studied further using SEM and energy dispersion X-ray micro analysis. In the case of the urea condensates a small amount of sulphamic acid has a significant influence on the reaction between phosphating agents and urea; in fact the presence of SA reduces the exothennic reaction. However, at high concentrations of urea, the exothermic reaction occurred at a higher temperature and a hard crystalline product was produced, thus application required dissolution in warm water (50•C). A urea condensate of 1 mole sulphamic acid, 1 mole phosphorus acid and up to 18 moles of urea could produce a durable flame retardant finish on cotton fabric. A higher amount of phosphorous acid in the urea ~ondensate products (IS/2PH/IOU) reduced the exotherm temperature and a high quality flame retardant effect was produced on cotton fabric. The evenness of phosphorus and sulphur elemental distribution on the surface and cross section of treated fibre was confirmed using SEM. Desirable flame retardancy effects from the urea condensate treated fabrics were obtained with comparatively low levels of sulphur and phosphorus (in comparison with the current commercially available Proban and Pyrovatex treated fabrics). However, in the washing process of the condensate-treated fabr ics, no significant reduction in P or S concentration/level was found. The excellent flame retardancy of the new system can be explained due to the N/P/S containing polymer formed on the surface of the fabric. DSC results from the treated fabrics confirmed these observations. Fabrics treated with Pro ban and Pyrovatex showed a very sharp exotherm after 300'C, but for fabrics treated with the urea condensates only a small exotherm effect appeared. In FT-IR analysis and NMR analysis, the production of aliphatic polymer chains of different length was verified , however, for the insoluble product formed in situ by heating at 160'C, and also for the condensates formed on the fabric at high temperature, a complicated polymer structure was shown to contain a possible combination of cyanuric acid, cyclic urea, triazine and melamine. All these materials have been identified in the FT-IR spectra of a water- insoluble urea product formed at 160•C. To make a model reaction with other hydroxyl group-containing substrates, starch and polyvinyl alcohol were treated with the ISI2PH/IOU condensate. The flame retardancy effect on both these treated substrates was confirmed by DSC thermal analysis. Advantages of this new wash-durable FR system over the currently available Proban/Pyrovatex systems include: no formaldehyde, low cost, ready availability of materials, simplicity of the treatment (no specific equipment required), and maintenance of all the desirable physical properties of the fabric, such as soft handle, acceptable tensile strength, no effect on dyed grounds and also no yellowing of the fabric.

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Les différentes phases du cycle de vie des textiles ignifugés (TIgni) ont des impacts importants sur l'environnement. Nombreuses études réalisées se sont principalement axées sur des méthodes de synthèse des molécules d’ignifugation. Cependant la phase de fin de vie des TIgni a été longtemps négligée, et nécessite aujourd’hui une attention particulière. Alors que la valorisation des déchets par incinération est une voie appropriée pour la gestion des déchets textiles, les TIgni posent des problèmes car les espèces ignifuges diminuent le rendement énergétique dans le processus d'incinération en raison d'une combustion incomplète et émettent des fumées toxiques. Nous proposons une méthode plus écologique de valorisation énergétique de ces déchets, par la dégradation et l'élimination préalable des substances ignifuges permanentes organophosphorés (MPDA) des textiles, en utilisant le procédé d'oxydation avancé (AOP) de Fenton. Ensuite, la valorisation thermique est réalisée par gazéification au lieu de l'incinération. La cinétique de dégradation de la MDPA, suivie en mesurant la DCO, semble dépendre des concentrations en réactifs de Fenton. Après ce traitement, les propriétés mécaniques du coton restent inchangées. Le test d'inflammabilité et les résultats thermogravimétriques (TGA, DTG et PCFC) confirment la dégradation du MDPA.Les résultats de gazéification montrent des propriétés de combustion accrues des textiles ignifuges après ce traitement qui permet donc d’éco-concevoir la valorisation énergétique de ces textiles. L’évaluation des impacts environnementaux réels en utilisant l’ACV permet de confirmer l’éco-conception de fin de vie des produits textiles ignifugés. / The different life cycle phases of textiles with flame retardant (FR) finishes have substantial adverse impacts on environment. Several studies on the exposure of flame retardant have mainly focused on ways to provide environmentally friendly synthesis of flame retardants. However the end-of-life phase of the FR textiles seems neglected and needs great attention when the product life cycle is concerned. Though today, technologies for solid waste management are ever-improving, the end-of-life of flame retardant textile products create issues, by decreasing energy yield in the incineration process due to incomplete combustion and emission of toxic fumes.Therefore an eco-design was proposed with optimized disposals for the flame retardant textiles, by a prior degradation and elimination of a durable flame retardant substance (MDPA) from textiles, using advanced oxidation Fenton process. Then thermal valorization was achieved by gasification instead of incineration.The degradation kinetics of MDPA from cotton fabrics, monitored by measuring the COD of the reaction mixture, seems to depend on the Fenton reactant concentration. The mechanical properties of the cotton after the treatment are unaltered. The flammability test and thermogravimetric (TGA, DTG and PCFC) results confirmed the degradation of MDPA. The gasification results supported the eco-design by showing increased combustion properties of the FR textiles after the Fenton treatment allowing eco-design of energy valorization of textile wastes. Real environmental impacts evaluated by a life cycle assessment (LCA) tool confirm the eco-design of the end-of-life phase of flame retardant textile products.

Cette étude s’inscrit dans le cadre du projet de recherche collaboratif FOMOTEX (FOnctionnalisation de MOusses et TEXtiles innovants). Son objectif est le développement d’un procédé d’encapsulation de produits actifs lipophiles et notamment de retardateurs de flamme pour la fonctionnalisation de textiles. Pour permettre leur liage aux fibres textiles, leur préparation est basée sur la synthèse d’une double membrane dont la première a un rôle protecteur et dont la deuxième, thermofusible, permet la fixation sur le support lors de la mise en œuvre. Ce mémoire porte ainsi sur la sélection des matériaux utilisés pour préparer les particules, sur leur mise en œuvre et sur la compréhension des mécanismes de synthèse ainsi que sur la caractérisation des particules permettant l’optimisation des paramètres de synthèse. Une première partie de ce travail traite de l’utilisation de nanoparticules de silice pour la stabilisation prolongée de l’émulsion, dite de Pickering et la limitation des phénomènes d’exsudation de l’actif. Leur influence sur l’encapsulation par des procédés sol-gel est également étudiée. Une seconde partie concerne l’étude de l’influence des paramètres de formulation et de synthèse sur les caractéristiques de microparticules et l’optimisation de l’encapsulation par des procédés sol-gel. Enfin, dans une dernière partie, le concept de microcoencapsulation double membrane avec la membrane externe thermoliante aux fibres textiles a été validé. / This study was performed as a part of FOMOTEX collaborative research project (functionalization foams and Innovative textiles). The purpose is the development of an encapsulation process of lipophilic product as flame retardants for the functionalization of textiles. To allow the bonding to textile fibers, their preparation is based on the synthesis of a double wall particles, the first wall having a protective role and the second, melt, allowing the linkage on the textile support during processing . This thesis focuses on the selection of materials to prepare the particles, on their processing and on the understanding of the synthesis mechanisms of particle and on their characterization to enable the optimization of synthesis parameters. A first part deals with the use of silica nanoparticles to extend the stabilization of the emulsion, called Pickering emulsion, and to limit the exudation phenomena of the active substance. Their influence on the encapsulation by sol-gel processes is studied. A second part concerns the study of the influence of formulation and synthesis parameters on micropaticules characteristics and the optimization of the encapsulation by sol-gel processes. Finally, in a last part, the concept of double wall microcoencapsulation, the outer membrane allowing bonding to textile fibers, has been validated.