An Ambassador as a Diversion? Giuliano Soderini and His Florentine Mission in France (1527–29)

In 1527, after the Sack of Rome by Imperial Troops, the Medici are chased from Florence. The oligarchic government of the Dieci is reinstated. The Dieci need a new ambassador. In particular, they need a man of trust in France, where the king ought still to be convinced to defend Florence and Tuscany against imperial troops. They choose pro-republic Bishop Giuliano Soderini of Saintes. The embassy and life of Giuliano Soderini have been strangely and almost systematically omitted in the existing literature on the subject. His letters were completely excluded from previous editions of Florentine letters of this period. This paper aims to restore them to their rightful place. It presents Giuliano Soderini’s personal and political background before and after his French mission. His diplomatic functions, needs and difficulties are detailed thanks to an extended and thorough reading of his correspondence in and out of France, preserved in France and Italy. This archival work led to the writing of an updated catalogue of his diplomatic correspondence from July 1527 to February 1529

Self-healing waterborne polyurethane dispersions

222 p.Se sintetizaron nuevas dispersiones acuosas de PU(U) auto-curativas mediante la incorporación de disulfuros aromáticos dinámicos. La microestructura de estos PU(U)s fue optimizada jugando sistemáticamente con bloques incorporados en la columna vertebral de la cadena polimérica. Esto mejoró las propiedades mecánicas de los PU(U)s a temperatura ambiente, al mismo tiempo que logró suficiente movilidad para el cierre de arañazos a temperaturas moderadas. De esta manera, demostramos que la brecha que existe entre la investigación académica sobre los PU(U)s auto-curativos y las aplicaciones de recubrimientos industriales de PU(U) puede ser superada. Además, quedó claro que para estos recubrimientos tan fuertes el papel principal de los enlaces dinámicos de disulfuro es mejorar la movilidad, mientras que los enlaces hidrógenos proporcionan resistencia mecánica al recubrimiento. Sin embargo, más investigación es necesaria ya que todavía existen desafíos en la aplicación de PUUs fuertes como revestimientos protectores y auto-curativos.Polyma

Flexible aromatic disulfide monomers for high-performance self-healable linear and cross-linked poly(urethane-urea) coatings

Implementation of the self-healing concept in coatings is challenging because they have to combine mechanical strength and chain mobility. This challenge is addressed in this work by studying the effect of the polymer microstructure on the mechanical properties and self-healing ability of waterborne poly(urethane-urea) coatings containing aromatic disulfide dynamic bonds. The structural modifications studied are the concentration and flexibility of the aromatic disulfide units and the effect of cross-linking. The effects and limits of these structural changes on the mechanical properties of the polymers and their healability were determined via a combination of DMA measurements, tensile tests, and rheological and scratch closure experiments. It was found that the flexibility of the disulfide unit was key to develop more efficient self-healing materials which offer the necessary molecular mobility for self-healing while simultaneously maintaining a level of mechanical strength that are essential for coating applications.The European Union’s Horizon 2020 research and innovation programme is accredited for the financial support through Project TRACKWAY-ITN 642514 under the Marie Sklodowska-Curie grant agreement. N.B. acknowledges the financial support obtained through the Post-Doctoral fellowship Juan de la Cierva - Incorporación (IJCI-2016-28442), from the Ministry of Economy and Competitiveness of Spai

Synthesis of mechanically strong waterborne poly(urethane-urea)s capable of self-healing at elevated temperatures

Although various chemistries have been introduced into polyurethanes in order to obtain self-healing abilities, implementing these materials in applications requiring high strength is challenging as strong materials imply a limited molecular motion, but without movement of polymer chains self-healing is not possible. Here, waterborne poly(urethane-urea)s (PU(U)s) based on aromatic disulfide compounds are developed which balance these contradictory requirements by presenting good mechanical properties at room temperature, while showing the mobility necessary for healing when moderately heated. The influence of hard monomers on the stability and mobility of the materials is investigated by scratch closure, cut healing and rheological measurements, so that the limits of the readily available aromatic disulfide compounds, bis(4-aminophenyl)- and bis(4-hydroxyphenyl)disulfide, can be determined. Subsequently, a modified aromatic disulfide compound, bis[4-(3'-hydroxypropoxy)phenyl]disulfide, with increased reactivity, solubility and flexibility is synthesized and incorporated into the PU backbone, so that materials with more attractive mechanical properties, reaching ultimate tensile strengths up to 23 MPa, and self-healing abilities at elevated temperatures could be obtained.The European Union’s Horizon 2020 research and innovation programme is accredited for the financial support through Project TRACKWAY-ITN 642514 under the Marie Sklodowska-Curie grant agreement. N.B. acknowledges the financial support obtained through the Post-Doctoral fellowship Juan de la Cierva - Incorporación (IJCI-2016-28442), from the Ministry of Economy and Competitiveness of Spai

Organics in comet 67P – a first comparative analysis of mass spectra from ROSINA–DFMS, COSAC and Ptolemy

The ESA Rosetta spacecraft followed comet 67P at a close distance for more than 2 yr. In addition, it deployed the lander Philae on to the surface of the comet. The (surface) composition of the comet is of great interest to understand the origin and evolution of comets. By combining measurements made on the comet itself and in the coma, we probe the nature of this surface material and compare it to remote sensing observations. We compare data from the double focusing mass spectrometer (DFMS) of the ROSINA experiment on ESA's Rosetta mission and previously published data from the two mass spectrometers COSAC (COmetary Sampling And Composition) and Ptolemy on the lander. The mass spectra of all three instruments show very similar patterns of mainly CHO-bearing molecules that sublimate at temperatures of 275 K. The DFMS data also show a great variety of CH-, CHN-, CHS-, CHO2- and CHNO-bearing saturated and unsaturated species. Methyl isocyanate, propanal and glycol aldehyde suggested by the earlier analysis of the measured COSAC spectrum could not be confirmed. The presence of polyoxymethylene in the Ptolemy spectrum was found to be unlikely. However, the signature of the aromatic compound toluene was identified in DFMS and Ptolemy data. Comparison with remote sensing instruments confirms the complex nature of the organics on the surface of 67P, which is much more diverse than anticipated

COMETS AVIS 2018-36 - LE HARCÈLEMENT SEXUEL DANS LES LABORATOIRES : QUELQUES CONSIDÉRATIONS ÉTHIQUES

COMETS Comité d'éthique du CNRS Avis n°2018-36Avis n°2018-36, approuvé en séance plénière du COMETS le 5 mars 2018