54 research outputs found

    ROMP of novel hindered phenol-functionalized norbornenes and preliminary evaluation as stabilizing agents†

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    A series of new norbornene monomers containing sterically hindered phenol groups have been synthesized and polymerized via ring-opening metathesis polymerization (ROMP) using the Grubbs 3rd generation catalyst (G3’). ROMPs exhibit first-order kinetics and molar masses increase linearly with monomer conversion and well-controlled phenol hindered-functionalized polynorbornenes were obtained with a monomer to initiator ratio up to 1 000. The first-order rate constants show that the ROMP activity is closely associated with the norbornene monomer steric congestion. The antioxidant behavior of these hindered phenol-containing polynorbornenes with different para-bridged side groups in polypropylene (PP) was estimated by onset oxidation temperature (OOT) measurements. The ability of these hindered phenol-containing norbornenes to copolymerize by ROMP with dicyclopentadiene (DCPD) was used to bound covalently the antioxidant moiety onto a polydicyclopentadiene (PDCPD) resin whose thermal ageing has been investigated.We thank Mireille Barthe and Alexandre Bénard for SEC analyses and Sullivan Bricaud for NMR analyses. We acknowledge finan- cial support from Le Mans University, CNRS, and the French National Research Agency (VRPOM project, ANR-15-CE08-0025)

    Nouvelle contribution au classement typologique des cuirs archéologiques : le cas des chaussures

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    Quelles informations les chutes de fabrication peuvent-elles apporter sur l’artisanat du cuir au Moyen âge ?

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    Jusqu’à une époque très récente, les chutes de cuir découvertes lors d’opérations archéologiques étaient souvent jetées après avoir été brièvement mentionnées dans les comptes rendus d’opération. Cependant, une nouvelle approche de ce mobilier permet d’apporter un éclairage nouveau sur l’artisanat du cuir pendant le Moyen Âge. Ainsi, après avoir présenté les critères permettant de reconnaître une chute de fabrication, nous décrirons la typologie qui peut en être dressée et les informations qui peuvent être déduites de leur étude.Until very recently, the leather waste discovered during excavations was very often thrown away or only mentioned in the reports. A new interest for this material reveals that these discarded offcuts can bring a new lighting on leathercraft during Middle Age. In this paper, we first present the criteria of the offcut, the typology we can made off and then the informations we obtain from the analyse

    Cuirs

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    International audienc

    Pourquoi jeter et non pas recycler ses chaussures au Moyen Âge ?

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    International audienc
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