Facile and efficient chemical functionalization of aliphatic polyesters by cross metathesis
International audience; An effective preparation of new tailor-made macromolecular materials via a combination of two (atom-efficient) catalytic transformations is reported. First, new aliphatic polyesters with alternated composition have been prepared using a salen aluminum catalyst system. Next, the pendant vinyl moieties in those copolymers have been selectively transformed into various functional groups by metathesis in the presence of homogeneous Grubbs catalysts. The latter metathesis reaction has been optimized in terms of catalytic activity and selectivity, to define the conditions for an effective and safe procedure that does not affect the macromolecular architecture. All polymer …
Design and development of 100 % bio-based high-grade hemp/epoxy composites
International audience; In order to develop 100% bio-based high-grade epoxy composites, in this study, bio-based epoxy thermosets and hemp slivers are processed and characterized by different technologies. Epoxy resins are synthesized from the diglycidylether of Eugenol, extracted from cloves. They are cured with bio-based acid anhydrides. The physicochemical properties of the resulting epoxy resins are characterized using thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), and nanoindentation. The mechanical properties of hemp fibres extracted from the slivers are also determined using tensile tests. After their processing and characterization, these bio-based consti…
Multicatalytic Transformation of (Meth)acrylic Acids: a One-Pot Approach to Biobased Poly(meth)acrylates
International audience; Shifting from petrochemical feedstocks to renewable resources can address some of the environmental issues associated with petrochemical extraction and make plastics production sustainable. Therefore, there is a growing interest in selective methods for transforming abundant renewable feedstocks into monomers suitable for polymer production. Reported herein are one-pot catalytic systems, that are active,<br>productive, and selective under mild conditions for the synthesis of copolymers from renewable materials. Each system allows for anhydride formation, alcohol acylation and/or acid esterification, as well as polymerization of the formed (meth)- acrylates, providi…
Design and synthesis of biobased epoxy thermosets from biorenewable resources
International audience; Biobased diepoxy synthons derived from isoeugenol, eugenol or resorcinol (DGE-isoEu, DGE-Eu and DGER, respectively) have been used as epoxy monomers in replacement of the diglycidyl ether of bisphenol A (DGEBA). Their curing with six different biobased anhydride hardeners leads to fully biobased epoxy thermosets. These materials exhibit interesting thermal and mechanical properties comparable to those obtained with conventional petrosourced DGEBA-based epoxy resins cured in similar conditions. In particular, a high Tg in the range of 90–130 °C and instantaneous moduli higher than 4.3 GPa have been recorded. These good performances are very encouraging, making these n…
Manuel de bonnes pratiques professionnelles des centres d’investigation clinique
Resume Les centres d’investigation clinique (CIC) sont des structures de recherche clinique academiques appartenant a un reseau national, coordonne par l’Institut national de la sante et de la recherche medicale (Inserm) et la Direction generale de l’offre de soins (DGOS), comportant des groupes de travail et des reseaux thematiques. Le groupe « Harmonisation des procedures des CIC » (HPCIC) a elabore un manuel de bonnes pratiques professionnelles, presente dans cet article. Le manuel a ete elabore par consensus, relu par les coordonnateurs des CIC, des experts externes, et valide par des representants des deux tutelles Inserm et DGOS. Le manuel de bonnes pratiques professionnelles des CIC …