Yes / The “sliding graft copolymer” (SGC), in which many linear poly-ε-caprolactone (PCL) side chains are bound to cyclodextrin rings of a polyrotaxane (PR), was prepared and employed to toughen brittle polylactide (PLA) with methylene diphenyl diisocyanate (MDI) by reactive blending. The SGC was in situ crosslinked and therefore transformed from a crystallized plastic into a totally amorphous elastomer during reactive blending. Meanwhile, PLA-co-SGC copolymer was formed at interface to greatly improve the compatibility between PLA and SGC, and the chain extension of PLA also occurred, were confirmed by FTIR, GPC, SEM, and TEM. The resulting PLA/SGC/MDI blends displayed super impact toughness, elongation at break and nice biocompatibility. It was inferred from these results the crosslinked SGC (c-SGC) elastomeric particles with sliding crosslinking points performed as stress concentrators and absorbed considerable energy under impact and tension process. / This work was supported by the National Natural Science Foundation of China (50933001, 51221002 and 51320105012).

This study deals with reactively compatibilized Polyamide 6 / High Density Polyethylene blends. More precisely, it focuses on the relationship between (1) the formulation, the processing parameters in corotating twin screw extrusion and (2) the morphologies and the microstructures of blends. Multi-scale morphologies were observed by Scanning and Transmission Electron Microscopy. At the micron scale, the following morphologies were developed: nodular dispersions, stretched nodules and co-continuous morphology. As the processing conditions did not influence the types of morphology, the different morphological regions were reported in ternary diagrams. In the case of compatibilized blends, two mechanisms for morphology development have been proposed: (1) the compatibilization reaction, being very fast, leads to the formation of nano-dispersions by interfacial instabilities and (2) the standard break-up/coalescence mechanism of domains poor in copolymer could lead to the formation of morphologies up to the micron scale. Both the evolution of the largest size as a function of the composition and the distribution of sizes were modeled using percolation concepts. The stability of the morphologies was then studied either during static annealing or controlled shear or in a second step processing. The copolymer formed at the interface allows stabilizing the size of the morphologies. Finally, crystallization at lower temperature was observed by Differential Scanning Calorimetry when the polymers are confined in submicron domains.

Cette étude s’intéresse aux mélanges Polyamide 6 / Polyéthylène Haute Densité compatibilisés par voie réactive, plus particulièrement aux relations entre (1) la formulation, les paramètres de mise en œuvre en extrusion bivis corotative et (2) la morphologie et la microstructure des mélanges. Des morphologies multi-échelles ont été observées en Microscopie Électronique à Balayage et en Transmission. À l’échelle micrométrique, les morphologies suivantes ont été développées : dispersion nodulaire, nodules étirés et co-continuité. Les paramètres procédés n’influençant pas le type morphologie, les régions correspondant aux types de morphologies ont pu être rassemblées sur des diagrammes ternaires. Dans le cas des mélanges compatibilisés, deux mécanismes de formation de ces morphologies sont proposés : (1) la réaction de compatibilisation très rapide et efficace entraîne la formation de nano-dispersions par instabilités d’interface et (2) le mécanisme classique de rupture/coalescence de domaines moins riches en copolymère permet de former des morphologies jusqu’à l’échelle micrométrique. L’évolution de la taille maximale des domaines en fonction de la composition ainsi que la distribution de tailles ont été modélisés par des mécanismes de percolation. La stabilité des morphologies en statique, sous cisaillement contrôlé et au cours d’une deuxième étape de mise en forme a ensuite été étudiée. Le copolymère formé à l’interface permet de stabiliser la taille des morphologies. Enfin, une cristallisation à plus basse température a été mise en évidence en Calorimétrie Différentielle à Balayage lorsque les polymères sont confinés dans des domaines submicroniques. / This study deals with reactively compatibilized Polyamide 6 / High Density Polyethylene blends. More precisely, it focuses on the relationship between (1) the formulation, the processing parameters in corotating twin screw extrusion and (2) the morphologies and the microstructures of blends. Multi-scale morphologies were observed by Scanning and Transmission Electron Microscopy. At the micron scale, the following morphologies were developed: nodular dispersions, stretched nodules and co-continuous morphology. As the processing conditions did not influence the types of morphology, the different morphological regions were reported in ternary diagrams. In the case of compatibilized blends, two mechanisms for morphology development have been proposed: (1) the compatibilization reaction, being very fast, leads to the formation of nano-dispersions by interfacial instabilities and (2) the standard break-up/coalescence mechanism of domains poor in copolymer could lead to the formation of morphologies up to the micron scale. Both the evolution of the largest size as a function of the composition and the distribution of sizes were modeled using percolation concepts. The stability of the morphologies was then studied either during static annealing or controlled shear or in a second step processing. The copolymer formed at the interface allows stabilizing the size of the morphologies. Finally, crystallization at lower temperature was observed by Differential Scanning Calorimetry when the polymers are confined in submicron domains.

O poli(ácido láctico) (PLA) é um polímero biodegradável, biocompatível e bioabsorvível proveniente de fontes renováveis. Constitui uma excelente alternativa sustentável para substituição dos polímeros provenientes de petróleo, atualmente dominantes no mercado industrial. Apesar das vantagens, o PLA tem baixa tenacidade e reduzida elongação na ruptura a temperatura ambiente, o que torna a sua utilização limitada em usos que necessitem de alta deformação plástica em níveis de exigência mecânicos elevados. Misturas mecânicas de PLA com polímeros altamente flexíveis, como é o caso da poli(ε-caprolactona) (PCL), podem resultar em novos materiais com propriedades mecânicas adequadas para diferentes aplicações. Blendas PLA/PCL são completamente imiscíveis, sendo seu comportamento mecânico altamente dependente da interação interfacial entre os componentes da blenda. Portanto, o objetivo desse trabalho é avaliar o efeito compatibilizante de um copolímero em bloco de baixa massa molar (2000 g mol-1) derivado de ε-caprolactona e policarbonato (C2) e, disponível comercialmente em blendas imiscíveis PLA/PCL. Blendas binárias e ternárias foram preparadas por mistura mecânica no estado fundido via processo de extrusão em rosca simples. O teor de PLA nas blendas foi de 75, 50 e 25% (em massa) e a concentração do copolímero de 0, 1, 3, 5 e 7% (em massa). O comportamento térmico, morfológico e mecânico das blendas compatibilizadas e não compatibilizadas foi avaliado por Calorimetria Exploratória Diferencial (DSC), Análise Termodinâmico-Mecânica (DMTA), Microscopia Eletrônica de Varredura (MEV) e ensaios de tração, flexão e impacto Izod. Os resultados de DSC e DMTA indicaram que o copolímero provocou pequena redução na temperatura de transição vítrea (Tg) do PLA, sugerindo que o C2 é solúvel no PLA. Entretanto, nas micrografias das superfícies de fraturas do PLA foi nítida a presença de pequenas micelas formadas pelo copolímero em bloco, indicando que há um limite de solubilidade do compatibilizante na fase de PLA. Os resultados obtidos em tração mostraram que com o aumento do teor de compatibilizante, a tensão no escoamento, a tensão na ruptura e o módulo elástico das blendas sofrem alterações. A propriedade de tenacidade, avaliada no ensaio de impacto Izod, mostrou que as blendas tiveram um ganho na resistência quando comparadas com o PLA puro. Os resultados mostraram que o copolímero em bloco derivado de ε-caprolactona e policarbonato alifático pode atuar como compatibilizante para blendas PLA/PCL / Poly(lactic acid) (PLA) is a biodegradable, biocompatible and bioabsorbable polymer from renewable sources. It is an excellent sustainable alternative for replacing petroleum polymers, currently dominant in the industrial market. Despite the advantages, PLA has low toughness and reduced elongation at room temperature, which makes its use limited in uses that require high plastic deformation under high mechanical stress levels. Mechanical mixtures of PLA with highly flexible polymers, such as poly(ε-caprolactone) (PCL), may result in new materials with mechanical properties suitable for different applications. PLA/PCL blends are completely immiscible, and their mechanical behavior is highly dependent on the interfacial interaction between the components of the blend. Therefore, the objective of this work is to evaluate the compatibilizing effect of a low molar mass block copolymer (2000 g mol-1) derived from ε-caprolactone and polycarbonate (C2) and commercially available in PLA/PCL immiscible blends. Binary and ternary blends were prepared by mechanical mixing in the melted state via single-screw extrusion process. The content of PLA in the blends was 75, 50 and 25% (% by mass) and the copolymer concentration was 0, 1, 3, 5 and 7% (% by mass). The thermal, mechanical and morphological behavior of compatibilized and non-compatibilized blends was evaluated by differential scanning calorimetry (DSC), thermodynamic-mechanical analysis (DMTA), scanning electron microscopy (SEM), tensile test, flexion test, and Izod impact. The results of DSC and DMTA indicated that the copolymer caused a small reduction in the glass transition temperature (Tg) of PLA, suggesting that C2 is soluble in PLA. However, in the micrographies of the fracture surfaces of the PLA the presence of small micelles formed by the block copolymer is clear, indicating that there is a limit of solubility of the compatibilizer in the PLA phase. The results obtained in a tensile test showed that with the increase of the compatibilizing content, the tension in the flow, the tension at rupture and the elastic modulus of the blends undergo changes. The tenacity property, evaluated in the Izod impact test, showed that the blends had a gain in resistance when compared to pure PLA. The results showed that block copolymer derived from ε-caprolactone and aliphatic polycarbonate can act as a compatibilizer for PLA/PCL blends.

O poli(ácido láctico) (PLA) é um polímero biodegradável, biocompatível e bioabsorvível proveniente de fontes renováveis. Constitui uma excelente alternativa sustentável para substituição dos polímeros provenientes de petróleo, atualmente dominantes no mercado industrial. Apesar das vantagens, o PLA tem baixa tenacidade e reduzida elongação na ruptura a temperatura ambiente, o que torna a sua utilização limitada em usos que necessitem de alta deformação plástica em níveis de exigência mecânicos elevados. Misturas mecânicas de PLA com polímeros altamente flexíveis, como é o caso da poli(ε-caprolactona) (PCL), podem resultar em novos materiais com propriedades mecânicas adequadas para diferentes aplicações. Blendas PLA/PCL são completamente imiscíveis, sendo seu comportamento mecânico altamente dependente da interação interfacial entre os componentes da blenda. Portanto, o objetivo desse trabalho é avaliar o efeito compatibilizante de um copolímero em bloco de baixa massa molar (2000 g mol-1) derivado de ε-caprolactona e policarbonato (C2) e, disponível comercialmente em blendas imiscíveis PLA/PCL. Blendas binárias e ternárias foram preparadas por mistura mecânica no estado fundido via processo de extrusão em rosca simples. O teor de PLA nas blendas foi de 75, 50 e 25% (em massa) e a concentração do copolímero de 0, 1, 3, 5 e 7% (em massa). O comportamento térmico, morfológico e mecânico das blendas compatibilizadas e não compatibilizadas foi avaliado por Calorimetria Exploratória Diferencial (DSC), Análise Termodinâmico-Mecânica (DMTA), Microscopia Eletrônica de Varredura (MEV) e ensaios de tração, flexão e impacto Izod. Os resultados de DSC e DMTA indicaram que o copolímero provocou pequena redução na temperatura de transição vítrea (Tg) do PLA, sugerindo que o C2 é solúvel no PLA. Entretanto, nas micrografias das superfícies de fraturas do PLA foi nítida a presença de pequenas micelas formadas pelo copolímero em bloco, indicando que há um limite de solubilidade do compatibilizante na fase de PLA. Os resultados obtidos em tração mostraram que com o aumento do teor de compatibilizante, a tensão no escoamento, a tensão na ruptura e o módulo elástico das blendas sofrem alterações. A propriedade de tenacidade, avaliada no ensaio de impacto Izod, mostrou que as blendas tiveram um ganho na resistência quando comparadas com o PLA puro. Os resultados mostraram que o copolímero em bloco derivado de ε-caprolactona e policarbonato alifático pode atuar como compatibilizante para blendas PLA/PCL / Poly(lactic acid) (PLA) is a biodegradable, biocompatible and bioabsorbable polymer from renewable sources. It is an excellent sustainable alternative for replacing petroleum polymers, currently dominant in the industrial market. Despite the advantages, PLA has low toughness and reduced elongation at room temperature, which makes its use limited in uses that require high plastic deformation under high mechanical stress levels. Mechanical mixtures of PLA with highly flexible polymers, such as poly(ε-caprolactone) (PCL), may result in new materials with mechanical properties suitable for different applications. PLA/PCL blends are completely immiscible, and their mechanical behavior is highly dependent on the interfacial interaction between the components of the blend. Therefore, the objective of this work is to evaluate the compatibilizing effect of a low molar mass block copolymer (2000 g mol-1) derived from ε-caprolactone and polycarbonate (C2) and commercially available in PLA/PCL immiscible blends. Binary and ternary blends were prepared by mechanical mixing in the melted state via single-screw extrusion process. The content of PLA in the blends was 75, 50 and 25% (% by mass) and the copolymer concentration was 0, 1, 3, 5 and 7% (% by mass). The thermal, mechanical and morphological behavior of compatibilized and non-compatibilized blends was evaluated by differential scanning calorimetry (DSC), thermodynamic-mechanical analysis (DMTA), scanning electron microscopy (SEM), tensile test, flexion test, and Izod impact. The results of DSC and DMTA indicated that the copolymer caused a small reduction in the glass transition temperature (Tg) of PLA, suggesting that C2 is soluble in PLA. However, in the micrographies of the fracture surfaces of the PLA the presence of small micelles formed by the block copolymer is clear, indicating that there is a limit of solubility of the compatibilizer in the PLA phase. The results obtained in a tensile test showed that with the increase of the compatibilizing content, the tension in the flow, the tension at rupture and the elastic modulus of the blends undergo changes. The tenacity property, evaluated in the Izod impact test, showed that the blends had a gain in resistance when compared to pure PLA. The results showed that block copolymer derived from ε-caprolactone and aliphatic polycarbonate can act as a compatibilizer for PLA/PCL blends.

Les tanins condensés sont largement répandus et très abondants dans la nature. Au cours des dernières décennies, ces tanins ont été abondamment utilisés pour la production de formulations thermodurcissables (par exemple, les adhésifs pour le collage du bois, les matériaux en mousse) en raison de leur réactivité chimique. Cependant, ils présentent également un grand potentiel en tant que composants pour la conception de matériaux polymères innovants en raison de leurs propriétés physico-chimiques (p. ex. antioxydantes, antimicrobiennes et stabilisantes). Afin d’étendre les domaines d’utilisation des tanins aux matériaux polymères, le principal verrou scientifique et technique réside dans leur incompatibilité avec les polymères hydrophobes. À cette fin, trois voies de modification ont été mises au point pour améliorer la compatibilité des tanins avec les matrices PP ou PLA. Dans la première partie, les PP/ tanins ont été modifiés avec du glyoxal par vulcanisation dynamique. Après extrusion réactive, les tanins vulcanisés présentent une meilleure compatibilité avec la matrice PP et des propriétés anti-UV. La deuxième approche consiste en une modification par estérification à l'aide d'anhydride acétique. Avec cette méthode, des teneurs élevées en AT ont pu être incorporées au PLA, jusqu'à 30 % en poids et jusqu'à 20 % sans diminution notable des propriétés mécaniques ni impact sur la morphologie de surface. Ces composites PLA/AT sont imprimables en impression 3D par dépôt de matière fondue. Dans la troisième partie, une compatibilisation réactive a été réalisée avec succès pour améliorer l'adhésion interfaciale entre PLA et les tanins condensés en utilisant du 3-aminopropytriéthoxysilane, du diisocyanate de méthylène diphényle et du peroxyde de dicumyle (DCP). / Condensed tannins are widely distributed and highly abundant in nature. In the past decades, such tannins have played an important role in thermosetting systems (e.g. adhesives for wood bonding, foam material) because of their chemical reactivity. However, they also exhibit great potential as a component of polymeric materials because of their physicochemical properties (e.g. antioxidant, antimicrobial and stabilizing properties), which are promising for material preparation. In order to transform tannins from traditional application to a broaden application in polymeric materials, the main challenge facing tannins are their incompatibility with hydrophobic polymer. For this purpose, three modification pathways were developed to improve the compatibility of tannins with PP or PLA matrix. In the first part, PP/ tannins were modified with hexamine or glyoxal via dynamic vulcanization technique. After vulcanized extrusion, vulcanized tannins present better compatibility and UV protective performance in PP matrix. The second approach is CTs modified with acetic anhydride. With this method, up to 30 wt% acetylated tannin (AT) can be well incorporated with PLA while PLA containing up to 20 wt% AT did not deteriorate the mechanical property and surface morphology. This PLA/AT composites are printable via fused deposition modeling process. In the third part, the efficient reactive compatibilization have been successful used to improve the interfacial adhesion between PLA and CTs by using 3-aminopropytriethoxysilane, methylene diphenyl diisocyanate, and dicumyl peroxide (DCP).

L'enjeu de ce travail est de comprendre les paramètres contrôlant les mécanismes de développement des morphologies et notamment la formation des nanodispersions pour des mélanges binaires de polyamides 6 de différentes masses molaires et de polyéthylène haute densité greffé anhydride maléique, mis en oeuvre par extrusion réactive. Le choix stratégique des matériaux a permis de balayer une large gamme de rapports de viscosité ainsi que différentes architectures de copolymères formés à l'interface. Les mécanismes de nature rhéologique ont été isolés méthodiquement des mécanismes dus à la réaction à l'interface en étudiant, d'une part, des mélanges non compatibilisés PA6/PEHD, puis l'effet de la réaction de compatibilisation seule en condition statique. Différents mécanismes de rupture de gouttes basés sur des instabilités capillaires sont proposés selon le rapport de viscosité. L'observation de microstructures ordonnées de copolymères aux interfaces en condition statique démontre la déstabilisation de l'interface fortement relié à la symétrie des copolymères formés. Les propriétés rhéologiques des mélanges sont étudiées ensuite. Les mécanismes de relaxation observés sont discutés, en particulier ceux liés aux interfaces et aux interactions entre nodules, en lien avec les morphologies des mélanges. Dans les mélanges compatibilisés, le comportement type gel ou solide-élastique (forte augmentation de l'élasticité aux basses fréquences), pour les mélanges concentrés, suggère la création d'un réseau percolant d'interactions entre nodules voisins. Enfin, un modèle performant de prédiction de la composition à l'inversion de phase à partir du comportement rhéologique est proposé / The aim of this work is to understand the parameters that control the morphology development mechanisms, and especially, the formation of nanodispersions. This study deals with binary blends of polyamide 6 of different molecular weights and maleic anhydride grafted high density polyethylene, processed by reactive extrusion. The strategic choice of blend components allowed to cover a wide range of viscosity ratio and various copolymer architectures formed at the interface. Mechanisms controlled by classical rheological laws were methodically isolated from mechanisms specific to the compatibilization reaction at the interface by studying, on the one hand, uncompatibilized PA6/HDPE blends, and on the other hand, the effect of the compatibilization reaction in static condition. Different drop break-up mechanisms based on capillary instabilities are proposed depending on viscosity ratios. The observation of ordered microphase separated copolymer domains at the interfaces in static condition attests of the spontaneous interface destabilization, strongly related to the copolymer asymmetry. Blends rheological properties are then studied. The different relaxation mechanisms obtained are discussed, especially those related to the interfaces and interactions between droplets, relatively to blends morphologies. In compatibilized blends, gel-like or solid-elastic behavior (strong elasticity increase at low frequencies) for concentrated blends, suggest the creation of a percolating network of interactions between neighboring droplets. Finally, an efficient model for predicting the phase inversion composition from the rheological behavior is proposed

Les thermoplastiques contenant du PDMS ont attiré beaucoup d’attention à cause de leur potentiel dans un large spectre d’applications. Lors du mélange du PDMS avec des thermoplastiques, le problème de la compatibilité ne peut être ignoré. Cette dernière engendre de faibles propriétés mécaniques ainsi qu’une surface rugueuse. Par conséquent, le défi principal des mélanges PDMS/thermoplastique est de trouver un moyen efficace et adapté, comme le mélange réactif in situ, pour compatibiliser les différentes phases. Récemment, nous avons trouvé une réaction intéressante entre l’hydrosilane (SiH) et les groupes carbonyles catalysés par le triruthénium dodecacarbonyle [Ru3(CO)12]. Il a le potentiel pour réaliser cette compatibilisation réactive. Dans un premier temps, nous avons étudié le mécanisme de la réaction d’hydrosilylation catalysée par le ruthénium dans le cas du N-méthylpropionamide. Les composés N-silicatés formés qui peuvent jouer par la suite le rôle de compatibilisant lors du mélange réactif. Dans un deuxième temps, cette réaction d’hydrosilylation a été étendue au mélange réactif de PA12 avec du PDMS terminé hydride en conditions de mélange fondu. La réaction a été réalisée rapidement (en 1 minute) en présence de Ru3 (CO) 12 (1wt%). Ensuite, nous avons étudié la microstructure des deux mélanges. En comparaison avec le mélange non réactif, la dispersion du PDMS dans celui réactif était clairement améliorée puisque la taille des domaines. En outre, dans de telles conditions réactives et en présence du catalyste de ruthénium, une réaction d’oxydation du PDMS-SiH est partiellement observée. Ceci inclue par exemple les propriétés de stabilité thermique, de comportement cristallin, d’énergie de surface et de perméabilité et séparation des gaz. Dans un troisième temps, nous nous sommes intéressés à l’application de la réaction d’hydrosilylation catalysée par le ruthénium aux composites PBT/polyméthylhydrosiloxane (PMHS). Cependant, à cause des températures élevées nécessaires à la mise en forme du PBT (220°C), une réaction de réticulation entre le PBT et le PMHS apparait mais également et une auto-réticulation du PMHS. Enfin, ces résultats montrent une application potentielle et initial de ruthénium hydrosilylation catalysées à compatibilisation réactive entre l'hydropolysiloxane et un polyamide ou un polyester / Polydimethylsiloxane (PDMS) containing thermoplastics have attracted much attention due to their potential in wide range of applications. However, when blending PDMS with thermoplastics, the incompatible problem cannot be ignored. It may results in weak mechanical properties and a rough surface. Therefore, the main challenge of PDMS and thermoplastic blend is to find an efficient and convenient way like in situ reactive blending to realize the compatibilization between tthem. Recently, we found an interesting reaction between hydrosilane (SiH) and carbonyl group catalyzed by triruthenium dodecacarbonyl [Ru3(CO)12]. It has potential to realize such reactive compatibilization. Firstly, we investigated the mechanism of ruthenium catalyzed hydrosilylation reaction of N-methylpropionamide, and found that the formed N-silylated compounds which can work as compatibilizers in later reactive blending. Then this hydrosilylation reaction was extended to the reactive blending of PA12 with hydride terminated PDMS under molten processing conditions. The reaction was carried out quickly (in 1 minute) in the presence of Ru3(CO)12 (1wt%). Compared to the unreacted one, the dispersion of PDMS after reaction was obviously improved. Besides, in such reactive conditions, PDMS-SiH oxidation reaction was partially observed. This phenomenon leads to a second PDMS gel based phase. Properties like thermal stability, crystalline behavior, surface energy and gas permeability and separation of such blends were also studied. Secondly, ruthenium catalyzed hydrosilylation was also applied to PBT and polymethylhydrosiloxane (PMHS) which was processed at higher temperature (220°C). The final material includes the crosslinking network formed between PBT and PMHS and a part of PMHS self-crosslinking forming PMHS gel-like phase due to the higher processing temperature of PBT and high reactivity of PMHS. Finally, these results show a potential and initial application of ruthenium catalyzed hydrosilylation to reactive compatibilization between hydride polysiloxane and polyamide or polyester