21 research outputs found
In melt preparation of biologically active polymeric materials
L’objectif de cette thèse était d’allier, dans un même polymère, le contrôle de l’architecture macromoléculaire, la fonctionnalité et la possibilité de sa mise en oeuvre en phase fondue, tout en préservant l’aspect environnemental. Les structures polymères synthétisées sont basées sur des chaînes biodégradables et/ou biosourcées d’acide polylactic (PLA), de polyhydroxybutyrate (PHB) et de polycaprolactone (PCL). Ces dernières ont été assemblées dans des structures macromoléculaires branchées à design contrôlé et portant des fonctions thiols, ces fonctions ont permis le greffage de monomères dotés de groupements ammoniums quaternaires, sur les structures obtenues, via une addition radicalaire thiol-ène.Les produits obtenus ont été mélangés en phase fondue, par extrusion, avec des matrices de PLA et de PCL, pour préparer des films. Ces derniers ont fait l’objet d’une étude d’activité antibactérienne qui a montré une grande efficacité envers différents types de bactériesThe aim of this work was to develop polymers that combine controlled macromolecular architectures, functionality, melt processing and an environmentally friendly aspect. The obtained polymeric structures were based on biodegradable and/or biosourced chains of polylactic acid (PLA), polycaprolactone (PCL) and polyhydroxybutyrate (PHB). The lasts were assembled in branched macromolecular structures with controlled design and bearing thiol functions, these functions allowed the grafting of quaternary ammoniumcontaining monomers on the branched structures according to a thiol-ene radical addition mechanism. The final products were blended with neat matrices of PLA and PCL in the melt state, by extrusion process, to make polymeric films. The obtained film-shaped blends were subjected to antibacterial activity study showing there high efficiency against different types of bacteri
Branched Biodegradable Functional Polymers with Controlled Macromolecular Design and Functionality: From Synthesis to Application
Branched Biodegradable Functional Polymers with Controlled Macromolecular Design and Functionality: From Synthesis to Application
International audienc
Elaboration en phase fondue de matériaux polymères à activité biologique
The aim of this work was to develop polymers that combine controlled macromolecular architectures, functionality, melt processing and an environmentally friendly aspect. The obtained polymeric structures were based on biodegradable and/or biosourced chains of polylactic acid (PLA), polycaprolactone (PCL) and polyhydroxybutyrate (PHB). The lasts were assembled in branched macromolecular structures with controlled design and bearing thiol functions, these functions allowed the grafting of quaternary ammoniumcontaining monomers on the branched structures according to a thiol-ene radical addition mechanism. The final products were blended with neat matrices of PLA and PCL in the melt state, by extrusion process, to make polymeric films. The obtained film-shaped blends were subjected to antibacterial activity study showing there high efficiency against different types of bacteriaL’objectif de cette thèse était d’allier, dans un même polymère, le contrôle de l’architecture macromoléculaire, la fonctionnalité et la possibilité de sa mise en oeuvre en phase fondue, tout en préservant l’aspect environnemental. Les structures polymères synthétisées sont basées sur des chaînes biodégradables et/ou biosourcées d’acide polylactic (PLA), de polyhydroxybutyrate (PHB) et de polycaprolactone (PCL). Ces dernières ont été assemblées dans des structures macromoléculaires branchées à design contrôlé et portant des fonctions thiols, ces fonctions ont permis le greffage de monomères dotés de groupements ammoniums quaternaires, sur les structures obtenues, via une addition radicalaire thiol-ène.Les produits obtenus ont été mélangés en phase fondue, par extrusion, avec des matrices de PLA et de PCL, pour préparer des films. Ces derniers ont fait l’objet d’une étude d’activité antibactérienne qui a montré une grande efficacité envers différents types de bactérie
Elaboration en phase fondue de matériaux polymères à activité biologique
The aim of this work was to develop polymers that combine controlled macromolecular architectures, functionality, melt processing and an environmentally friendly aspect. The obtained polymeric structures were based on biodegradable and/or biosourced chains of polylactic acid (PLA), polycaprolactone (PCL) and polyhydroxybutyrate (PHB). The lasts were assembled in branched macromolecular structures with controlled design and bearing thiol functions, these functions allowed the grafting of quaternary ammoniumcontaining monomers on the branched structures according to a thiol-ene radical addition mechanism. The final products were blended with neat matrices of PLA and PCL in the melt state, by extrusion process, to make polymeric films. The obtained film-shaped blends were subjected to antibacterial activity study showing there high efficiency against different types of bacteriaL’objectif de cette thèse était d’allier, dans un même polymère, le contrôle de l’architecture macromoléculaire, la fonctionnalité et la possibilité de sa mise en oeuvre en phase fondue, tout en préservant l’aspect environnemental. Les structures polymères synthétisées sont basées sur des chaînes biodégradables et/ou biosourcées d’acide polylactic (PLA), de polyhydroxybutyrate (PHB) et de polycaprolactone (PCL). Ces dernières ont été assemblées dans des structures macromoléculaires branchées à design contrôlé et portant des fonctions thiols, ces fonctions ont permis le greffage de monomères dotés de groupements ammoniums quaternaires, sur les structures obtenues, via une addition radicalaire thiol-ène.Les produits obtenus ont été mélangés en phase fondue, par extrusion, avec des matrices de PLA et de PCL, pour préparer des films. Ces derniers ont fait l’objet d’une étude d’activité antibactérienne qui a montré une grande efficacité envers différents types de bactérie
Microwaves; a promising solution for the in-melt elaboration of innovative materials
International audienceMicrowaves; a very promising solution for the in-melt elaboration of innovative materials. Kedafi Belkhir, Fréderic BecquartUniversité de Lyon, Ingénierie des Matériaux Polymères, UMR CNRS 5223, Université de Saint-Etienne, Jean Monnet, F-42023 Saint-Etienne, France Microwaves have gained a growing interest these last decades due to their ability to interact directly with materials having “good” dielectric properties i.e. polar or ionic systems. Then, microwave technology found major and very efficient applications in ceramics elaboration, drying and cooking in food industry. In chemistry and polymer chemistry, microwaves find more and more applications thanks to their direct wave-matter interaction leading to rapid heating and faster reactions. Their higher selectivity also favors reactions without solvent, with higher yields and limited side reactions. These promising advantages explain the dramatic growth of academic scientific production in chemistry and polymer chemistry under microwaves. [1]In polymer chemistry, microwaves are used for polymerization, chemical modification, grafting, depolymerization, pyrolysis and other processes. Both synthetic polymers, biosourced ones like polyesters and a majority of natural polymers from biomass are involved. This potential of application is very high and real with the additional possibilities to achieve reactions with less amounts of, or without, catalysts (atom economy) and lower energy consumption than the conventional conductive heating. Thus, microwaves are naturally an attractive way to face the current societal challenges. [2]However, one major counterpart exists, due to its selective interaction with the most polar bonds at the molecular scale in a reactive system, some heterogeneous heating with hot spots, may appear (Figure 1) [3]. So, we propose to present conceptually how it could be possible to take advantage from both this selectivity and this heterogeneity in the specific polymer reactive systems which could be biphasic. Biphasic polymer systems are very common in polymer blends or filled polymers, especially reactive systems are performed without solvent, at high temperature in the molten state and ideally under shear. In this way, microwaves offer the exclusive possibility to innovate in polymer science. Some concrete examples will illustrate the presented concepts. Figure 1. Microwave-generated hot spots in dispersed Pd/AC catalyst during Suzuki-Myaura reaction with different stirring rates.[1] A. Loupy; Microwave in Organic Synthesis; 2008;2nd Ed;WILEY-VCH[2] L. Zong et al. J. Microw. Power. Electromagn. Energy. 2003, 38, 49-74.[3] S. Horikoshi et al. Ind. Eng. Chem. Res. 2014, 53, 14941-14947
Microwaves; a promising solution for the in-melt elaboration of innovative materials
International audienceMicrowaves; a very promising solution for the in-melt elaboration of innovative materials. Kedafi Belkhir, Fréderic BecquartUniversité de Lyon, Ingénierie des Matériaux Polymères, UMR CNRS 5223, Université de Saint-Etienne, Jean Monnet, F-42023 Saint-Etienne, France Microwaves have gained a growing interest these last decades due to their ability to interact directly with materials having “good” dielectric properties i.e. polar or ionic systems. Then, microwave technology found major and very efficient applications in ceramics elaboration, drying and cooking in food industry. In chemistry and polymer chemistry, microwaves find more and more applications thanks to their direct wave-matter interaction leading to rapid heating and faster reactions. Their higher selectivity also favors reactions without solvent, with higher yields and limited side reactions. These promising advantages explain the dramatic growth of academic scientific production in chemistry and polymer chemistry under microwaves. [1]In polymer chemistry, microwaves are used for polymerization, chemical modification, grafting, depolymerization, pyrolysis and other processes. Both synthetic polymers, biosourced ones like polyesters and a majority of natural polymers from biomass are involved. This potential of application is very high and real with the additional possibilities to achieve reactions with less amounts of, or without, catalysts (atom economy) and lower energy consumption than the conventional conductive heating. Thus, microwaves are naturally an attractive way to face the current societal challenges. [2]However, one major counterpart exists, due to its selective interaction with the most polar bonds at the molecular scale in a reactive system, some heterogeneous heating with hot spots, may appear (Figure 1) [3]. So, we propose to present conceptually how it could be possible to take advantage from both this selectivity and this heterogeneity in the specific polymer reactive systems which could be biphasic. Biphasic polymer systems are very common in polymer blends or filled polymers, especially reactive systems are performed without solvent, at high temperature in the molten state and ideally under shear. In this way, microwaves offer the exclusive possibility to innovate in polymer science. Some concrete examples will illustrate the presented concepts. Figure 1. Microwave-generated hot spots in dispersed Pd/AC catalyst during Suzuki-Myaura reaction with different stirring rates.[1] A. Loupy; Microwave in Organic Synthesis; 2008;2nd Ed;WILEY-VCH[2] L. Zong et al. J. Microw. Power. Electromagn. Energy. 2003, 38, 49-74.[3] S. Horikoshi et al. Ind. Eng. Chem. Res. 2014, 53, 14941-14947
Microwaves; a promising solution for the in-melt elaboration of innovative materials
International audienceMicrowaves; a very promising solution for the in-melt elaboration of innovative materials. Kedafi Belkhir, Fréderic BecquartUniversité de Lyon, Ingénierie des Matériaux Polymères, UMR CNRS 5223, Université de Saint-Etienne, Jean Monnet, F-42023 Saint-Etienne, France Microwaves have gained a growing interest these last decades due to their ability to interact directly with materials having “good” dielectric properties i.e. polar or ionic systems. Then, microwave technology found major and very efficient applications in ceramics elaboration, drying and cooking in food industry. In chemistry and polymer chemistry, microwaves find more and more applications thanks to their direct wave-matter interaction leading to rapid heating and faster reactions. Their higher selectivity also favors reactions without solvent, with higher yields and limited side reactions. These promising advantages explain the dramatic growth of academic scientific production in chemistry and polymer chemistry under microwaves. [1]In polymer chemistry, microwaves are used for polymerization, chemical modification, grafting, depolymerization, pyrolysis and other processes. Both synthetic polymers, biosourced ones like polyesters and a majority of natural polymers from biomass are involved. This potential of application is very high and real with the additional possibilities to achieve reactions with less amounts of, or without, catalysts (atom economy) and lower energy consumption than the conventional conductive heating. Thus, microwaves are naturally an attractive way to face the current societal challenges. [2]However, one major counterpart exists, due to its selective interaction with the most polar bonds at the molecular scale in a reactive system, some heterogeneous heating with hot spots, may appear (Figure 1) [3]. So, we propose to present conceptually how it could be possible to take advantage from both this selectivity and this heterogeneity in the specific polymer reactive systems which could be biphasic. Biphasic polymer systems are very common in polymer blends or filled polymers, especially reactive systems are performed without solvent, at high temperature in the molten state and ideally under shear. In this way, microwaves offer the exclusive possibility to innovate in polymer science. Some concrete examples will illustrate the presented concepts. Figure 1. Microwave-generated hot spots in dispersed Pd/AC catalyst during Suzuki-Myaura reaction with different stirring rates.[1] A. Loupy; Microwave in Organic Synthesis; 2008;2nd Ed;WILEY-VCH[2] L. Zong et al. J. Microw. Power. Electromagn. Energy. 2003, 38, 49-74.[3] S. Horikoshi et al. Ind. Eng. Chem. Res. 2014, 53, 14941-14947
Polymer Processing under Microwaves
International audienceOver the last decades, microwave heating has experienced a great development and reached various domains of application, especially in material processing. In the field of polymers, this unusual source of energy showed important advantages arising from the direct microwave/matter interaction. Indeed, microwave heating allows regio-, chemio-, and stereo-selectivity, faster chemical reactions, and higher yields even in solvent-free processes. Thus, this heating mode provides a good alternative to the conventional heating by reducing time and energy consumption, hence reducing the costs and ecological impact of polymer chemistry and processing. This review states some achievements in the use of microwaves as energy source during the synthesis and transformation of polymers. Both in-solution and free-solvent processes are described at different scales, with comparison between microwave and conventional heating
Thiol-ene grafting from polylactic acid, polycaprolactone, and polyhydroxybutyrate
International audienceThiol-ene additions of different monomers from multi-thiol functionalized biodegradable polymers are analyzed in this study. These monomers include quaternary ammonium groups known for their biological activities; and also methyl methacrylate (MMA) and hydroxyethyl methacrylate (HEMA), which are used to control the hydrophilic-hydrophobic balance in the issued copolymers. Monomer conversion and the resulting polymer structures are confirmed principally by H-1 nuclear magnetic resonance (NMR) spectra. Model reactions are first conducted with thiophenol, and then polylactic acid (PLA), polycaprolactone (PCL), and polyhydroxybutyrate (PHB) multi-thiol functionalized polymers are successfully used. The structures of the obtained products are analyzed by H-1 NMR spectra: all the reactions are kinetically controlled and monomer additions are controllable. Chain transfer constants of the used monomers to the multi-thiol functionalized PLA are between 1.4 and 1.9. The obtained products were also characterized by size-exclusion chromatography (SEC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA)