Synthesis of photocurable macromonomers based on biobased L-lysine and their polymerization under UV irradiation for coating applications

Les matières premières biosourcées s'avèrent être une possibilité de substitution du pétrole de plus en plus prisée dans le domaine des matériaux. De plus, l'utilisation de procédé propre limitant l'impact environnemental du développement de matériau est aujourd'hui incontournable. Dans ce contexte, l'acide aminé L-lysine, un nouveau synthon issu des biotechnologies blanches peu étudié dans le domaine de la chimie des matériaux, a été retenu. Ce synthon sera modifié pour la conception de macromonomères polymérisables sous irradiation UV. En effet, la technique de photopolymérisation est un procédé propre en plein essor, et qui permet le développement de revêtement.La L-lysine étant peu soluble dans les milieux organiques classiques, une étape de transformation est nécessaire pour améliorer sa processabilité. Ainsi, la polycondensation en masse de la L-lysine a conduit à des oligomères de poly-L-lysine de faibles masses molaires. La détermination de la structure obtenue a été réalisée par différentes techniques d'analyses. Ces oligomères sont alors greffés par des fonctions photopolymérisables dans des conditions douces. Le choix s'est porté sur des fonctions accepteur et donneur d'électron. Enfin, l'étude de la photopolymérisation des oligomères de L-lysine greffés accepteurs donneurs a été effectuée par la technique UV aqueuse, une technique innovante et respectueuse de l'environnement, dans différentes conditions pour en optimiser le système.Biobased raw materials are an interesting and promising option for the substitution of fossil resources in material design. Moreover, using green processes which limit environmental impact of the material conception can't be avoided nowadays. In this context, the L-lysine amino acid, a building block made by white biotechnologies and poorly described in material field has been evaluated. As photopolymerization is a green process in great expansion and allowing coating design, this building block has been modified into a photocurable macromonomer.L-lysine is hardly soluble in usual organic solvents, a transformation step is necessary in order to improve its processability. Thus, L-lysine polycondensation has been tackled and led to oligomers of poly-L-lysine with low molar mass and improved solubility. In addition, the structure determination has been undertaken by different analytic technics. These oligomers can thus be grafted with photocurable functional groups in mild conditions. The chosen photocurable functional groups are donor acceptor of electron. At last, the photopolymerization of L-lysine based oligomers grafted with donor acceptor functional groups has been done by UV waterborne technic which is innovative and environmentally friendly. The photopolymerization has been carried out in different conditions in order to optimize the process

Synthesis of pt nanoparticles in oil-in-water microemulsions: Phase behavior and effect of formulation parameters on nanoparticle characteristics

From the Proceedings from Formula VI in Stockholm 2010.Pt nanoparticles were synthesized in oil-in-water (o/w) microemulsions, in contrast to the typically used water-in-oil microemulsion method. The new strategy implies the use of a Pt orga-nometallic precursor (1,5-cyclooctadiene dimethyl platinum (II)), dissolved in nanometre-scale oil droplets, stabilized by surfactant, and dispersed in a continuous aqueous phase. Three different nonionic microemulsion systems were used. Characterization studies demonstrate that small, nanocrystalline Pt nanoparticles were obtained. The particle size and agglomeration was dependant on the microemulsion system used and its composition. The obtained results demonstrate the feasibility of this approach for the controlled synthesis of Pt nanoparticles with potential for catalytic purposes. © Taylor & Francis Group, LLC.This research work has been performed in the framework of the D43/004/06 COST Programme action. M. Sanchez-Dominguez is grateful to CSIC for a JAE-Doc contract. Financial support from Ministerio de Ciencia e Innovación (MICIN, Spain, Grant number CTQ2008-01979) and Generalitat de Catalunya (Grant number 2009-SGR-00961) are acknowledged.Peer reviewe

Syntheses of donor acceptor biobased photocurable water-soluble resins based on poly-L-lysine

International audienceWe report a new kind of coating using UV waterborne technique with a biobased poly(amino acid) resin. Firstly we performed the thermal polycondensation of L-lysine during 15 hours at 150 °C in order to synthesize water-soluble oligomers of poly-L-lysine (PLL) with 5-6 monomer units. These oligomers were then transformed in mild conditions to give photocurable water-soluble resins. We grafted on the poly-L-lysine backbone, allyl and maleamic acid functional groups, with a grafting rate close to 65% thanks to allyl glycidyl ether and maleic anhydride respectively. The influence of the reaction time and the reagents ratio on the grafting rate was investigated. Hence, the donor/acceptor photopolymerization of the mixture of allyl ether-poly-L-lysine (PLL-g-AE) with maleamic acid-poly-L-lysine (PLL-g-MA) in aqueous solution gave yellow transparent films. The degree of conversion and other kinetic parameters have been studied and detailed. This work contributes to the development of materials based on renewable resources and cleaner processes. It opens a new pathway to both fundamental and applied-driven research