Search results for "ROMP"

Nouvelle condamnation pour l'application Yuka

2022

Observations sous Tribunal de commerce d'Aix-en-Provence, 13 septembre 2021, no 2021-F004507 - Qualification de la décision : confirmation

Première condamnation au fond pour Yuka

2020

International audience; Observations sous Tribunal de commerce de Paris (1re ch.), 25 mai 2021, no 202100119 - Qualification de la décision : confirmation

A cross-cultural investigation of email communication in Peninsular Spanish and British English. The role of (in)formality and (in)directness

2013

This paper examines the email discursive practices of particular speakers of two different languages, namely Peninsular Spanish and British English. More specifically, our study focuses on (in)formality and (in)directness therein, for these lie at the heart of considerable scholarly debate regarding, respectively (i) the general stylistic drift towards orality and informality in technology-mediated communication, and (ii) the degree of communicative (in)directness – within broader politeness orientations – of speakers of different languages, specifically an orientation towards directness in Peninsular Spanish vis-à-vis indirectness in British English. The aim of this paper is thus to invest…

New practical tungsten(VI) based catalyst systems for ring opening metathesis polymerisation

2002

Abstract Tungsten(VI) complexes of the type trans -[WCl 2 (diol)(OAr) 2 ] were studied as catalyst precursors for ROMP of norbornene and dicyclopentadiene. These compounds form active catalysts when treated by simple Grignard reagents, such as methyl magnesium iodide or neophyl magnesium chloride. Moreover, polymerisations can be run under ambient atmosphere without complicated inert atmosphere techniques.

End Capping Ring-Opening Olefin Metathesis Polymerization Polymers with Vinyl Lactones

2008

The selective placement of a functional group at the chain end of a ring-opening metathesis polymer using ruthenium carbene initiators has been a significant limitation. Here we demonstrate a highly effective and facile end-capping technique for ROMP with living ruthenium carbene chain ends using single-turnover olefin metathesis substrates. Vinylene carbonate and 3H-furanone are introduced as functionalization and termination agents for the ruthenium-initiated ring-opening metathesis polymerization. This leads directly to the formation of functional polymer end groups without further chemical transformation steps. Aldehyde and carboxylic acid end groups can be introduced by this new method…

Rompiendo el silencio. Infancias amenazadas

2018

Polymerizable Well-Defined Oligo(thiophene amide)s and their ROMP Block Copolymers

2009

We report the synthesis of conjugated thiophene amide oligomers that constitute a new class of chromophores with potential for optoelectronic applications. The synthesis of defined norbornene-substituted oligothiophene amides using conventional coupling chemistry is described. Their electronic properties depend on the degree of oligomerization as UV/Vis and fluorescence spectroscopy demonstrate. A significant red shift in the spectra upon an increase in the oligomer length evidences conjugation of the thiophene rings via the amide linkages. ROMP of the norbornene-substituted oligomers gives homopolymers and block-copolymers with a solubilizing second block. The amphiphilic character of the …

An All-ROMP Route to Graft Copolymers

2007

A new versatile synthesis strategy for macromonomers has been developed that uses the living ring-opening metathesis polymerization (ROMP) with commercial Grubbs first generation ruthenium initiators. Homopolymers as well as diblock copolymers were end-functionalized with norbornene derivatives to serve as macromonomers. The graft copolymerization of the macromonomers was also carried out employing ROMP. Well-defined and highly functional graft copolymers are accessible by this new synthetic route.

Synthesis of Functional Block Copolymers Carrying One Poly(p-phenylenevinylene) and One Nonconjugated Block in a Facile One-Pot Procedure

2016

Block copolymers composed of a MEH–PPV block and a nonconjugated functional block (molecular weights between 5 and 90 kg/mol) were synthesized in a facile one-pot procedure via ROMP. This one-pot procedure permits the synthesis of numerous block copolymers with little effort. Amphiphilic block copolymers were obtained via incorporation of oxanorbornene carrying a PEG side chain as well as via postpolymerization modification of a reactive ester carrying norbornene derivative with methoxypoly(ethylene glycol)amine. These amphiphilic block copolymers can be self-assembled into micelles exhibiting different sizes (60–95 nm), morphologies (micelles or fused, caterpillar-like micelles), and optic…

Evolution des biominéralisations nacrées chez les mollusques : caractérisation moléculaire des matrices coquillières du céphalopode nautiloïde Nautil…

2008

In metazoan, molluscan shells are one of the most fascinating examples for the investigation of the calcium carbonate biomineralization phenomenon. These exoskeletons are secreted by the outer epithelium of the calcifying mantle. They are composed of 95% of mineral – calcite and/or aragonite -, the rest of the shells being constituted by a mixture of proteins, glycoproteins and polysaccharides, called the organic matrix. This calcifying matrix is directly involved in biomineralization. This PhD work is focussed on the characterization of organic components associated to the nacreous layer. In molluscs, the nacre is observed in shells of extent species of bivalves, gastropods, cephalopods an…