Les polyesters insaturés sont des résines thermodurcissables particulièrement appréciées pour leur facilité de mise en œuvre et leur coût modéré. Cependant, comme tous les polymères organiques ils ont une réaction au feu médiocre, ce qui est critique dans un certains nombres de d'applications. L'objectif de cette thèse était d'élaborer de nouvelles formulations de résines ayant un comportement au feu amélioré. La première stratégie développée a été le greffage de monomères phosponés dans la matrice polyester. Des monomères méthacryliques et styrénique ont été synthétisés et utilisés pour remplacer une partie du styrène dans la résine. La stabilité thermique des résines modifiées est diminuée, mais leur comportement au feu est globalement meilleur. Des effets du phosphore en phase gazeuse et en phase condensée ont pu être mis en évidence.Dans une seconde partie, une sélection de particules se distinguant par leur nature, leur taille et leur facteur de forme a été testée. Si l'impact des ces charges est assez limité lorsqu'elles sont utilisées individuellement, des tests calorimétriques ont révélé que certaines combinaisons de particules pouvaient améliorer significativement la réaction au feu des résines. Enfin, des associations d'additifs phosphorés et de particules submicroniques ont été investiguées. Le polyphosphate d'ammonium se distingue des autres additifs par un impact très important sur le comportement au feu et particulièrement par le charbonnement important qu'il engendre, cependant sa combinaison avec des charges inorganiques ne s'est pas révélée probante. / Unsaturated polyesters are thermoset resins particularly appreciated for their low cost and easy processing. Nevertheless one of their main drawbacks is their poor fire resistance. The aim of this PhD thesis was to prepare new resin formulations with an improved fire behaviour. The first part of this work was dedicated to the grafting of phosphorous monomers in the polyester matrix. Methacrylic and styrenic monomers were synthesized and used to replace of part of the styrene in the resin. Resin thermal stability was decreased, but on the whole their fire behaviour was improved. Condensed phase and gas phase effects of phosphorus were highlighted.In a second part, a screening of various kinds of particles with different sizes was performed. Calorimetric tests revealed that, while the effect of these particles used alone is limited, a decrease of resin flammability could be achieved with specific combinations. Finally, commercial phosphorous additives were associated with submicronic fillers. From all the additives tested, ammonium polyphosphate stands out, with a powerful impact on the resin fire reaction and especially a much increased charring. However, its combination with inorganic particles was not conclusive.

Zielsetzung dieser Arbeit war die Zähmodifizierung eines neuen besonders hochtemperaturbeständigen ungesättigten Polyesters, nachfolgend Referenz genannt. Im Rahmen dieser Arbeit wurden verschiedene konzeptionelle Ansätze verfolgt, um die Harz- und Duromer-Eigenschaften von hochtemperaturbeständigen ungesättigten Polyesterharzen (Unsaturated Polyester Resin, UPR) zu modifizieren und zu verstehen.:1. Einleitung 2. Motivation 3. Theoretischer Teil 4. Charakterisierungsmethoden 5. Ergebnisse und Diskussion 6. Zusammenfassung 7. Experimenteller Teil 8. Literaturverzeichnis 9. Anhang 10. Versicherung

<p>This dissertation focused on cured-in-place-pipe (CIPP) technology, which is being used to repair sewer pipes across the globe. The CIPP process involves the manufacture of a new fiber-reinforced composite plastic pipe inside an existing damaged pipe. By 2022, the global CIPP market will exceed $2.5 billion and constitute 40% of the U.S. pipe rehabilitation market. In recent years, concerns about the type, magnitude, and toxicity of chemical air emissions associated with CIPP installations have markedly increased. CIPP installations in Asia, Europe, Oceania, and North America have been associated with indoor and ambient air contamination incidents, afflicted schools, daycare centers, homes, and offices and prompted building evacuations. This research program was designed to better understand chemical release into the air during CIPP composite manufacture and the human health risks. Principles and techniques from the environmental engineering, air quality, material science, and risk analysis were applied. This dissertation contains three chapters and each chapter is a stand-alone manuscript, with the first chapter already having been published.</p><p>Chapter 1 involved the characterization of chemical emissions for steam-cured CIPP installations in Indiana (IN, sanitary sewer) and California (CA, storm sewer). It was discovered that a complex multiphase mixture of organic vapor, water vapor, and particulate (condensable vapor and partially cured resin) was emitted. Chemicals captured included a variety of hazardous air pollutants, carcinogens, endocrine disrupting compounds, and other chemicals with little toxicity data. The materials captured in California during 4 CIPP installations, when normalized against styrene concentration, exhibited different toxicity towards mouse cells. This toxicity indicated that non-styrene compounds were probably responsible for toxicity. Testing revealed significant and previously unreported worker and public safety chemical risks existed with CIPP installations.</p><p>Chapter 2 describes experiments conducted to determine which CIPP manufacturing conditions (i.e. curing pressure, temperature, time and ventilation) influenced chemical air emissions during and after composite manufacture. During thermal manufacture, approximately 8.87 wt% volatile organic compounds (VOC) was released into the air at standard pressure. For the CIPP styrene-based resin examined, chemical volatilization during manufacture was influenced by pressure, but temperature and heating time did not influence the composition of chemical residual inside the new composite. All cured composites, regardless of temperature or heating time, contained approximately 3 wt% VOC. No statistical difference was found for either: (1) VOC loading across cured composites or (2) styrene emission into the air across cured composites despite different curing temperature and heating times. Styrene was the most abundant compound detected in the composite and in air. High styrene air concentration signals inhibited the author’s ability to determine if other non-styrene compounds were emitted into the air. Short-term ventilation (2 hr) of the new composite reduced styrene air concentration to near zero in 10 min, but styrene levels rebounded when ventilation was halted. Due to the high styrene loading in the cured composite, it is expected that ventilation will only temporarily reduce VOC air levels in pipes, manholes, and other affected spaces.</p><p>Chapter 3 includes inhalation health risk assessment due to chemical emission from CIPPs during manufacture and use. Publicly available worksite data for ultraviolet (UV)-light and steam-CIPP installations were utilized and Monte Carlo simulation was applied. Data-gaps were also identified. Health risks associated with newly manufactured (post-cured) chemical emission from lab scale CIPPs were also evaluated. For CIPP resins and post-cured CIPPs 31 chemicals have been quantified among which many are unique volatile organic chemicals VOCs, but only 8 air testing studies were found. At a steam-CIPP worksite, VOCs were found in a condensed multiphase mixture discharged into air, 4 VOCs were detected in the vapor phase, while only styrene vapor phase results could be used for risk assessment. Worksite styrene levels (1,825 ppm_v, 1,070 ppm_v, 220-270 ppm_v, 140 ppm_v) have been reported indicating a health risk can exist. Monte Carlo simulation using literature data revealed that for the single UV-CIPP and single steam-CIPP study negligible styrene HQs were found, while unacceptable styrene LECRs% > 10⁻⁴ (i.e. 37-38%) were obtained. Monte Carlo simulation on laboratory data showed that post-cured emissions from the composite cured longer increased the unacceptable styrene LECR (from 17.86% to 21.12%) and HQ (0.95% to 8.04%). Whereas curing the composite at greater temperature reduced the styrene LECR and HQ to 0.89%. and 0, respectively. Ventilation also diminished the acceptable LECR% in all composites but did not reduce the carcinogenic health risk to an acceptable level. Health risk can exist as evidenced by limited air testing data. More studies are needed to examine inhalation health risks associated with the CIPP manufacturing process and newly manufactured plastics.</p>

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Made available in DSpace on 2014-12-17T14:58:10Z (GMT). No. of bitstreams: 1 LucieneMR_DISSERT.pdf: 3721446 bytes, checksum: 16ced8820ae92014f7d8c365770f515c (MD5) Previous issue date: 2011-08-11 / In the present research work, composites were prepared using pine apple leaf fibres (PALF) as reinforcement with unsaturated polyester resin as matrix, incorporating with fire retardant at different compositions. The PALF was obtained from the decortication of pine apple leaves obtained from Ramada 4 from Ielmo Marinho in the State of Rio Grande do Norte. The unsaturated polyester resin and the catalyzer were bought from the local establishment. The fire retardant, aluminium tri-hydroxide - Al(OH)3 was donated by Alcoa Alum?nio S.A and was used in the proportions of 20%, 40% and 60% w/w. Initially the fibres were treated with 2% NaOH for 1 hour, to remove any impurities present on the fibre surface, such as wax, fat, pectin and pectate, in order to have a better adsorption of the fibres with the matrix as well as the flame retardant. The fibre mat was prepared in a mat preparator by immersion, developed in the Textile Engineering Laboratory, at the UFRN. The composites (300x300x3 mm) were prepared by compression molding and the samples (150x25x3 mm) for analysis of the properties were cut randomly using a laser cutter. Some of the cut samples were used to measure the smoke emission and fire resistance using UL94 standard. Mechanical tension-extension and flexural properties were carried in CTG?s RN and the Laborat?rio de Metais e Ensaios Mec?nicos Engenharia de Materiais UFRN , as well as SEM studies were carried out at N?cleo de Estudos em Petr?leo e G?s Natural - UFRN . From the observed results, it was noted that, there was no marked influence of the fire retardant on the mechanical properties. Also in the water absorption test, the quantity of water absorbed was less in the sample with higher concentration of fire retardant. It was also observed that the increase in the proportion of the fire retardant increased the time of burning, may be due to the compactness of the composite due to the presence of fire retardant as a filling material even though it was meant to reduce the rate of inflammability of the composite / Na presente pesquisa foram desenvolvidos comp?sitos com fibras da folha do abacaxizeiro (PALF - Pineapple Leaf Fiber), utilizando resina de poli?ster insaturado como matriz, incorporando retardante de chama em diferentes composi??es. As fibras da folha do abacaxizeiro foram obtidas na ramada 4 do munic?pio de Ielmo Marinho no Estado do Rio Grande do Norte. A resina de poli?ster insaturado e o catalisador foram comprados no com?rcio. O retardante de chama de alumina trihidratada (hidr?xido de alum?nio - Al(OH)3) foi doado pela empresa Alcoa Alum?nio S.A. e foi utilizado em propor??es de 20%, 40% e 60% do peso do material utilizado na fabrica??o dos comp?sitos. As PALFs foram tratadas com 2% de hidr?xido de s?dio, por 1 hora, para eliminar as impurezas superficiais tais como ceras, gorduras, pectinas e pectatos, para que houvesse uma melhor ades?o da matriz ?s fibras, bem como do retardante de chama. As mantas de fibras foram preparadas num preparador de manta por imers?o, desenvolvido no Laborat?rio de Engenharia T?xtil da UFRN. Os comp?sitos (300x300x3 mm) foram moldados por compress?o e as amostras (150x25x3 mm) para an?lise das propriedades foram cortadas, em diferentes posi??es da placa do comp?sito com aux?lio de uma m?quina de laser. As propriedades mec?nicas de tra??o e flex?o em tr?s pontos foram realizadas no CTG?s RN e no Laborat?rio de Metais e Ensaios Mec?nicos de Engenharia de Materiais da UFRN. Os testes da emiss?o de fuma?a e resist?ncia ao fogo foram realizados no Laborat?rio de Engenharia T?xtil da UFRN, utilizando a norma UL94. As amostras resultantes das propriedades mec?nicas foram avaliadas no MEV do N?cleo de Estudos em Petr?leo e G?s Natural da UFRN. Com base nas an?lises dos resultados nos ensaios mec?nicos, observou-se que o retardante de chama n?o tem influ?ncia significativa. Tamb?m observou-se que no ensaio de abosor??o de ?gua, quanto maior a concentra??o de retardante de chama, a quantidade de ?gua absorvida ? menor. No teste de inflamabilidade, observou-se que quanto maior a concentra??o de retardante de chama, maior o tempo de queima. Pode ser conclu?do que a presen?a de retardante de chama, al?m de atuar como inibidor de chama, tamb?m atua como uma carga que influ?ncia a compacta??o do comp?sito e desta forma reduz a taxa de queima

On s’intéresse dans cette étude au potentiel de copolymères à blocs (BCP) de types PBA-b-P(MMA-co-DMA) et PBA-b-P(BA-co-DMA) en tant qu’additifs multifonctionnels nanostructurant la matrice thermodurcissable polyester insaturé de composites SMC et BMC. La nanostructuration de la résine polyester insaturé (UPR) est assurée par la ségrégation du bloc élastomère poly(acrylate de butyle), ainsi que par la miscibilité du deuxième bloc dans le réseau grâce à la bonne compatibilité des motifs diméthylacrylamide (auto-assemblage). Ces BCP sont tout d’abord étudiés en tant qu’agents renforçants et anti-retrait dans les composites SMC et BMC, en étant substitués et comparés aux additifs anti-retrait conventionnels PVAc et P(MMA-co-S) incorporés traditionnellement afin de compenser le retrait de la résine polyester. Ces additifs nanostructurants sont ensuite évalués en tant qu’agents de mûrissement des compounds SMC. La nanostructuration des BCP dans la résine UP réactive pouvant entrainer une importante augmentation de la viscosité (formation d’un gel), ces additifs pourraient peut-être constituer des agents de mûrissement plus efficaces que l’oxyde de magnésium couramment utilisé à cet effet. Une étude des matrices [UPR + BCP, UPR + PVAc et UPR + P(MMA-co-S)] est réalisée dans un premier temps, les composites BMC et SMC chargés par du carbonate de calcium et renforcés par des fibres de verre étant étudiés par la suite. En absence de charges et de fibres de verre (matrice seule), la nanostructuration est moins efficace que la macroséparation de phase des additifs conventionnels PVAc et P(MMA-co-S) pour compenser le retrait du réseau polyester. Dans un composite en revanche, la nanostructuration conduit à une compensation du retrait intermédiaire entre celles du P(MMA-co-S) et du PVAc. Au niveau de la matrice seule, la nanostructuration permet d’éviter une diminution conséquente de l’énergie de rupture du réseau polyester et permet même dans certains cas une amélioration significative de cette dernière, alors que les additifs conventionnels engendrent un effondrement de cette propriété. Cette différence est cependant beaucoup moins visible dans le cas des composites, les charges entrainant une fissuration prématurée de la matrice. Un composite nanostructuré peut tout de même présenter un renforcement significatif par rapport aux composites conventionnels lorsqu’il contient des nanovides compensateurs de retrait de tailles conséquentes qui améliorent la ténacité du matériau. En ce qui concerne le mûrissement d’un compound SMC par nanostructuration au cours du refroidissement (passage de la transition ordre-désordre), si l’augmentation de la viscosité d’un système réactif UPR + BCP semble suffisamment importante et abrupte, elle est cependant insuffisante en présence des charges ou alors intervient à une température trop faible en raison de l’influence de ces dernières sur la nanostructuration. / The aim of this study is to evaluate the potential of PBA-b-P(MMA-co-DMA) and PBA-b-P(BA-co-DMA) block copolymers (BCP) as multifunctional additives nanostructuring the unsaturated polyester thermosetting matrix of SMC and BMC composites. The nanostructuration of the unsaturated polyester resin (UPR) is ensured by the segregation of the poly(butyl acrylate) elastomeric block, and by the miscibility of the second block in the thermoset thanks to the good compatibility of dimethylacrylamide units (self-assembly). These BCP are first studied as reinforcing and anti-shrinkage agents in SMC and BMC composites, as compared to conventional low profile additives PVAc and P(MMA-co-S) traditionally blended to compensate the polyester resin shrinkage. These nanostructuring additives are then studied as thickening agents in SMC compounds. As the nanostructuration of BCP in the UP reactive resin can lead to a high viscosity increase (gel formation), BCP might provide a more efficient thickening than the conventional additive magnesium oxide. Matrices are studied first [UPR + BCP, UPR + PVAc and UPR + P(MMA-co-S)], BMC and SMC composites filled with calcium carbonate and reinforced by chopped glass fibres being then considered. In the absence of fillers and fibres (neat matrix), the nanostructuration is less efficient than the macrophase separation of PVAc and P(MMA-co-S) to compensate the polyester resin shrinkage. However, in a composite, the nanostructuration leads to an intermediate shrinkage compensation between those of P(MMA-co-S) and PVAc. In the neat matrix, the nanostructuration avoids a substantial decrease of polyester network toughness and can even lead sometimes to a significant reinforcement, whereas conventional additives decrease tremendously this property. However, this difference is not observed in composites, fillers giving rise to an early cracking of the matrix. A nanostructured composite can still present a significant reinforcement compared to conventional composites when it contains large nanovoids (compensating shrinkage) which improve the fracture toughness of the material. As regards the thickening of an SMC compound by nanostructuration during cooling (crossing of the order-disorder transition), the viscosity increase of a UPR + BCP reactive system seems important and sharp enough, but in the presence of fillers the viscosity increase is not sufficient or the order-disorder transition temperature is too low because of the influence of fillers on the nanostructuration.

De par leurs bonnes propriétés mécaniques, leur faible densité, leur faible coût, et leur bel aspect de surface, les composites SMC (Sheet Molding Compound) sont des matériaux de choix pour réaliser des pièces automobiles semi-structurelles. Ces matériaux sont principalement constitués d’une résine polyester (UPR), d’un additif thermoplastique comme agent anti-retrait, de carbonate de calcium comme charge et de fibres de verre coupées comme renfort. Le contexte environnemental et socio-économique actuel encourage les constructeurs automobiles à utiliser des matériaux issus de ressources renouvelables afin de réduire l’utilisation des réserves pétrolières, et de trouver une alternative au styrène (COV, polluant atmosphérique dangereux et potentiellement cancérigène) qui est utilisé comme diluant réactif (DR) dans les UPR. L’objectif de ce travail est de développer une matrice organique biosourcée (UPR et agent anti-retrait) pour composite SMC moulable par le même procédé de mise en forme et présentant le même niveau de performance comparé à l’existant pétrosourcé. La première partie de ce travail est consacrée à l’évaluation de nouveaux diluants réactifs biosourcés (MMA, BDDMA, BDDVE, EDI, IBOMA et LMA) comme substituants du styrène sur la base des contraintes liées au procédé SMC. Les résines sélectionnées ont ensuite été polymérisées et les réseaux obtenus caractérisés. Le mécanisme de copolymérisation a été étudié et a permis de mettre en évidence l’influence de la nature chimique des insaturations et de la fonctionnalité du DR sur les propriétés finales du réseau. De par sa faible viscosité, sa faible volatilité et son point éclair élevé, le BDDMA est un bon candidat pour remplacer le styrène dans les UPR. La partie suivante est consacrée à la caractérisation d’un prépolymère polyester insaturé et de différents agents anti-retrait biosourcés. Des matrices organiques ont été formulées avec différents agents anti-retrait, puis polymérisées et caractérisées. L’influence de la nature et du taux d’agent anti-retrait sur le retrait de polymérisation et les propriétés mécaniques a été évaluée. Des essais sur composites SMC à l’échelle pilote ont été réalisés afin d’étudier les propriétés finales des composites biosourcés. La meilleure compensation du retrait est obtenue pour l’additif de plus faible Tg, c'est-à-dire le polyester saturé biosourcé. Le réseau à base de BDDMA étant très fragile, la suite de ce travail a consisté à réduire la densité de réticulation du réseau en introduisant un monométhacrylate biosourcé dans la formulation (MMA, IBOMA et LMA) afin d’améliorer les propriétés au choc du matériau. Enfin, un nouveau DR biosourcé, le lévulinate de vinyle, a été évalué comme substituant du styrène dans les UPR. Le mécanisme de copolymérisation a été mis en évidence et relié à la structure et aux propriétés finales du réseau. / Due to their good mechanical properties, low density, low cost and good surface properties, SMC composites (Sheet Molding Compound) are suitable for manufacturing half-structural automotive parts. These materials are mainly based on a unsaturated polyester resin (UPR), thermoplastics as low profile additives, calcium carbonate as filler and chopped glass fibers. Current environmental and socio-economic concerns motivate automotive manufacturers to use bio-based materials in order to reduce the use of crude oil reserves and to find an alternative to styrene (VOC, hazardous air pollutant, potential carcinogen) which is used as reactive diluents (RD) in UPR. The aim of this work was to develop a bio-based organic matrix (UPR and low profile additive) for SMC composites with a similar processability and same level of performances compared to petroleum-based analogs. The first part of this work describes the evaluation of new bio-based reactive diluents (MMA, BDDMA, BDDVE, EDI, IBOMA and LMA) as styrene substituents for UPR, taking into account SMC process requirements. Selected resins were polymerized and the obtained networks characterized. Copolymerization mechanism was studied and allowed to highlight the influence of the chemical nature of unsaturations and the functionality of reactive diluents on network properties. Due to its low viscosity, low volatility and high flashpoint, BDDMA is a good candidate to replace styrene in UPR. Next part was dedicated to the characterization of bio-based unsaturated polyester and low profile additives. Several organic matrices were formulated with different low profile additives, then polymerized and characterized. The influence of the low profile additive nature and content on the polymerization shrinkage and mechanical properties of the material was evaluated. SMC composites were manufactured at the pilot scale and characterized in order to study the final properties of bio-based composites. The best shrinkage control is obtained with low-Tg additive (bio-based saturated polyester). Nevertheless BDDMA-based network is very brittle, so a next step of our work was to introduce a monofunctional methacrylate (MMA, IBOMA and LMA) into the matrix in order to decrease the crosslink density of the network and improve its impact resistance. The influence of the methacrylate nature and content on the structure and mechanical properties of the polyester networks was highlighted. Finally, a new bio-based RD, vinyl levulinate, was evaluated to replace styrene in UPR. Its copolymerization mechanism with UP was studied and related to the structure and mechanical properties of the network.