Synthesis of Fatty Acid-Based Polyesters and Their Blends with Poly(L-lactide) as a Way To Tailor PLLA Toughness

10.1021/sc500648gInternational audiencePolylactide (PLA) is one of the most mature biobased and biocompostable plastics currently in the market. Despite its mechanical properties comparable to the ones of some mainstream petroleum-based thermoplastics (PS, for instance), PLA inherent brittleness and heat sensitivity are issues for its full industrial development. In this study, we investigated the melt-blending of PLLA (poly-L-lactide) with fatty acid-based flexible polyesters as an efficient way to tailor PLLA toughness. To that aim, a set of aliphatic polyesters has been developed by taking benefit of the large range of biobased building blocks that can be obtained from plant oils. Melt-blending of the so-formed polyesters with PLLA resulted in improved properties that can be finely tailored by varying the structure and the properties of the plant-based polyester additives

6-O-glucose palmitate synthesis with lipase: Investigation of some key parameters

International audienceFatty acid sugar esters represent an important class of non-ionic bio-based surfactants. They can be synthesized from vinyl fatty acids and sugars with enzyme as a catalyst. Herein, the influence of the solvent, the lipase and the temperature on a model reaction between vinyl palmitate and glucose via enzymatic catalysis has been investigated and the reaction conditions optimized. Full conversion into 6-O-glucose palmitate was reached in 40 h in acetonitrile starting from a reactant ratio 1:1, at only 5%-wt loading of lipase from Candida antarctica B (CALB) without the presence of molecular sieves

Synthèse de Poly(3,4-ethylènedioxythiophène) en milieux dispersants organiques

L objectif de ce travail de thèse était de développer des encres organiques de polymères semi-conducteurs. Il s est ainsi agi de synthétiser des latex de poly (3,4-éthylènedioxythiophène) (PEDOT) dispersibles en milieux organiques (cyclohexane ou toluène) par polymérisation oxydative de l EDOT en présence de stabilisant stériques et/ou électrostatiques. Le stabilisant est un polymère fonctionnalisé par une unité ou plusieurs unités fonctionnelles qui peuvent réagir avec la chaîne de PEDOT en croissance assurant ainsi des liaisons covalentes ou électrostatiques entre celui-ci et le stabilisant. La taille des particules de PEDOT est contrôlée par la masse molaire, la concentration et par la fonctionnalité du stabilisant. Le PEDOT obtenu est caractérisé par diffusion de la lumière (DLS), par microscopie électronique à balayage (MEB) microscopie électronique à transmission (TEM) et par des mesures de conductivité.Spherical poly(3,4-ethylenedioxythiophene) nano-particles with narrow size distribution were prepared in organic dispersant media in the presence of iron(III) chloride FeCl3 or iron(III) dodecylbenzenesulfonate {Fe(DBS)3} as oxidant and a functionalized polyisoprene ( -R-PI) as a stabilizer. Two kinds of functionalized polyisoprene were used as stabilizers. Pyrrole, fluorene, Thiophene and methylthiophene end caped polyisoprenes were used as reactive stabilizers. Lithium sulfonate end caped polyisoprene was used as steric stabilizer. The effect of the nature of the solvent, the molar mass, the concentration, and the nature of the functional end unit of the stabilizer on the size and morphology of PEDOT particles were investigated. Polyisoprenes containing sulfonate groups were also used as steric/electrostatic stabilizers. By this way, the sulfonate groups act as counter ions for oxidized PEDOT leading to electrostatic attraction between it and the stabilizer, ensuring stabilization of the latex. Four kinds of polyisoprene-based steric electrostatic stabilizers having one or many sulfonate groups were prepared: sulfonate end-capped polyisoprene (PI-SO3Li), partially sulfonated polyisoprene (PIS), polyisoprene grafted to polystyrene sulfonate (PI-g-PSS) and polyisoprene grafted to polyisoprene sulfonate (PI-g-PIS). The effects of the molar mass of the stabilizer and the sulfonate group content on the PEDOT particle morphology were studied.PEDOT samples were characterized with transmission electron microscopy (TEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), dynamic light scattering (DLS) analysis and conductivity measurements.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

Impact of Fatty Acid Structure on CALB‐Catalyzed Esterification of Glucose

International audienceEnzymatic synthesis of fatty acid glucose esters from different fatty acyl donors were performed via enzymatic catalysis in the presence of CALB, using acetonitrile as the solvent. The acyl donor nature (fatty acid or fatty acid vinyl ester) and structure were varied. Lower reaction rates and lower conversions were obtained with fatty acids in comparison to their corresponding vinyl esters. Moreover, the acyl donor with the longest chain length gave the highest conversions. The presence of unsaturation on the acyl donor chain was also shown to be detrimental to the conversion

Synthèse de polyuréthanes par organo-catalyse dans le dioxyde de carbone supercritique

La synthèse de particules polyuréthane par organo-catalyse dans le dioxyde de carbone supercritique a été étudiée. Des réactions modèles ont été préalablement conduites et suivies par spectroscopie infrarouge in situ dans le CO2 supercritique afin d'identifier les catalyseurs organiques de réaction d'uréthanisation les plus efficients. Une série de polymères siliconés CO2-phile, porteurs de la fonction organo-catalytique en bout de chaîne (organo-catasurfs), a ensuite été préparée et testée dans le CO2 supercritique pour la polymérisation en dispersion de polyuréthane.The organocatalysed synthesis of polyurethane particles in supercritical carbon dioxide has been studied. Model reactions were first carried out in supercritical CO2 and monitored by in situ infrared spectroscopy in order to indentify the most efficient catalysts for the urethanisation reaction. A series of CO2-philic silicone polymers, end-functionalised with the organocatalytic group (organocatasurfs), were then synthesised and tested in supercritical CO2 for the dispersion polymerisation of polyurethane.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

Synthesis and Characterization of Epoxy Thermosetting Polymers from Glycidylated Organosolv Lignin and Bisphenol A

International audienceDiglycidylether of bisphenol A and isophorone diamine (IPDA) are industrially used for polyepoxide curing. Herein, glycidylated Organosolv lignin (GOL) is cured with diglycidyl ether of bisphenol A and IPDA for intensive studies. Organosolv lignin (OL) is therefore first glycidylated with epichlorohydrin to a material with an epoxy content of 3.2 mmol g–1 and analyzed via FT‐IR, 1H and 31P NMR. Epoxy thermosets with up to 42 wt% GOL are cured in differential scanning calorimetry (DSC) crucibles, analyzing the residual reaction heat. Characterization of dog bone shaped specimens is described with regard to structural properties from scanning electron microscopy and FT‐IR, thermal properties by DSC and thermogravimetric analysis, as well as mechanical properties by dynamic mechanical analysis and stress/strain measurements. A lignin content between 8% and 33% leads to higher crosslinking density, resulting in a higher glass transition, lower swelling percentage, and increased stiffness (Young's modulus) if compared to non‐GOL polymers

Nitrogen‐Containing Polymers Derived from Terpenes: Possibilities and Limitations

Nitrogen-containing polymers are widely applied materials, including polyamides, polyurethanes, and polyureas as well as epoxy thermosets. Their indispensability and the urgent need to replace fossil-based polymers considering more sustainable alternatives lead to significant efforts in exploring renewable feedstock as potential new building blocks. Being obtained from non-edible plant parts and often occurring as waste products, terpenes represent a promising group of renewable compounds that are of possible interest in the synthesis of nitrogen-containing polymers. The structural diversity of terpenes in combination with the mechanical properties that nitrogen-containing moieties bring into polymers can give rise to novel biobased materials that outstand mechanical and thermal properties of conventional fossil-based counterparts. In this review, an overview of the use of terpene compounds in the synthesis of nitrogen-containing polymers is given, covering different approaches to make use of terpenes as a valuable pool of renewable monomers