Showing papers by "Ghislain David published in 2016"
TL;DR: In this paper, a method to functionalize phenolic compounds with aliphatic aldehydes by a two-step reaction was proposed, i.e., the functionalization of an acetal group on aromatic hydroxyl functions and the subsequent deprotection of theses acetal groups into aldehyde groups.
60 citations
TL;DR: In this article, reactivity of aromatic aldehydes has been studied in function of the nature and positions of aromatic substituents prior to the aldehyde function, and it was shown that those bio-based compounds are not reactive in resol synthesis reactions but their reactivity can be triggered by masking their free-hydroxy groups.
58 citations
TL;DR: In this paper, a new method is proposed to calculate the flammability of polymers from their chemical structure using a Van Krevelen approach, inspired from the pioneering work of Lyon which assigns one flammable contribution to each chemical group.
27 citations
TL;DR: Chitosan, a renewable feedstock, is modified and used as a catalytic support in the presence of potassium iodide and demonstrates very good thermal stability and is recyclable more than five times without loss of activity.
Abstract: Chitosan, a renewable feedstock, is modified and used as a catalytic support in the presence of potassium iodide. The system is highly efficient towards the incorporation of carbon dioxide (CO2) into epoxides. It demonstrates very good thermal stability and is recyclable more than five times without loss of activity. The optimal reaction conditions were determined using allylglycidyl ether as a model and extended to a wide range of other epoxides. Cyclic carbonates were obtained with very high yield in a few hours under mild conditions (2–7 bar≈0.2–0.7 MPa, 80 °C) and no solvent.
22 citations
TL;DR: In this article, a high molecular weight chitosan was chemically modified to quantitatively incorporate quaternary ammonium groups, and its efficiency was evaluated in the liquid-solid separation for various liquors, and compared with the one of a polyelectrolyte usually used for this utilization.
Abstract: Abstract A high molecular weight chitosan was chemically modified to quantitatively incorporate quaternary ammonium groups. Its efficiency was evaluated in the liquid-solid separation for various liquors, and compared with the one of a polyelectrolyte usually used for this utilization. The performance of the liquid-solid separation was estimated through the determination of two parameters measured after the screening- settling of the mixture liquor/flocculating agent: the separation efficiency (EV) and the TS removal efficiency (ETS). Apart for liquor 6, TS removal was always better after an addition of functionalized chitosan. Furthermore, whatever the type of liquor, the distribution was modified by an increased presence of high-size particles when functionalized chitosan was added. Moreover, chitosan addition tended to homogenize the size of the particles, which could facilitate the choice of the liquid-solid separation process. This homogenization was particularly observed for the liquor initially highly dispersed in size, i.e. liquors 1, 4, 6 and 8.
5 citations
Patent•
20 Jan 2016TL;DR: In this paper, a propulsion nozzle is produced from an ablative resin, the method including a step of pre-polymerization wherein an innovative aldehyde compound is used.
Abstract: A method for producing a propulsion nozzle, wherein the nozzle is produced from an ablative resin, the method including a step of pre-polymerization wherein an innovative aldehyde compound is used.
4 citations
TL;DR: In this paper, new polymer blend membranes mixing a fluorinated polymer and a phosphonated polymer (poly(CTFE-alt-DEVEP)) have been prepared at low cost.
3 citations
Patent•
22 Feb 2016
TL;DR: In this article, a biosourced polymer obtained by dual chemical functionalization of chitosan, usable for catalytic carbonation of cyclic ethers by means of carbon dioxide, and a binder composition for creating layers and or coatings for road construction and/or civil engineering, marking materials, or sealing or insulation materials.
Abstract: The invention relates to a biosourced polymer obtained by dual chemical functionalization of chitosan, usable for catalytic carbonation of cyclic ethers by means of carbon dioxide, and a binder composition for creating layers and/or coatings for road construction and/or civil engineering, marking materials, or sealing or insulation materials. Said composition contains a polyhydroxyurethane polymer binder resulting from the reaction of at least one polyamine with at least one polycyclocarbonate. Said polycyclocarbonate was obtained by carbonating a (cyclic) poly(ether) with carbon dioxide catalyzed by said biosourced polymer.
3 citations
Patent•
20 Jan 2016
TL;DR: In this article, the presente invention concerne un procede de fabrication d'une resine ablative mettant en œuvre une reaction de reduction d'un compose de formule.
Abstract: La presente invention concerne un procede de fabrication d'une resine ablative mettant en œuvre une reaction de reduction d'un compose de formule A suivie d'une reaction de polymerisation.
Patent•
21 Oct 2016
TL;DR: In this paper, a method for producing a thruster nozzle made from phenolic resin having good thermal stability and charring properties is described, the method comprising: - the forming of a fibrous preform impregnated with a prepolymerised phenolic resins obtained from a mono-aromatic aldehyde compound having the following formula: formula (I) where n 1 is an integer between 1 and 3, n 2 is aninteger between 0 and 5 and, when n2 is greater than or equal to 2, the substituents R are identical or
Abstract: The invention relates to a method for producing a thruster nozzle made from phenolic resin having good thermal stability and charring properties, the method comprising: - the forming of a fibrous preform impregnated with a prepolymerised phenolic resin obtained from a mono-aromatic aldehyde compound having the following formula: formula (I) where n1 is an integer between 1 and 3, n2 is an integer between 0 and 5 and, when n2 is greater than or equal to 2, the substituents R are identical or different, R being chosen from: -COOH or the -O-Alk groups, where Alk designates an alkyl chain of 1 to 4 carbon atoms, the hydrocarbon chains comprising between 1 and 20 carbon atoms, and - curing the impregnated fibrous preform in such a way as to cross-link the prepolymerised phenolic resin.