Etienne Grau

Université Bordeaux 1 · UMR LCPO - Laboratoire de Chimie des Polymères Organiques

Polyhydroxyurethane (PHU) thermosets are the most promising isocyanate-free substitutes to polyurethane ones when targeting the main applications of the PU business (coatings, adhesives, foams). However, the curing of their solvent-free formulations at near room temperatures is often very slow and requires the utilization of organocatalysts, limiti...

Polyhydroxyurethane (PHU) thermosets are the most promising isocyanate-free substitutes to polyurethane ones when targeting the main applications of the PU business (coatings, adhesives, foams). However, the curing of their solvent-free formulations at near room temperatures is often very slow and requires the utilization of organocatalysts, limiti...

Prognostication in acute pulmonary embolism (PE) requires reliable markers. While cellular indices such as neutrophil‐to‐lymphocyte ratio (NLR), platelet‐to‐lymphocyte ratio (PLR), and systemic immune‐inflammation index (SII) appear promising, their utility in PE prognostication needs further exploration. We utilized data from the RIETE registry an...

The impact of water, added as a diluent, on the sol-gel transition of a model polyhydroxyurethane (PHU) thermoset was investigated using multiwave rheology. An impressive 2 to 5 fold decrease in gel-time, tgel, was observed for water content ranging from 2 wt% to 10 wt% at temperatures close to r.t. (30°C), indicating that water strongly accelerate...

Polyurethane (PU) thermoplastics and thermosets were prepared through the step-growth polymerization of in situ generated polyisocyanates through the decarboxylation of polyoxamic acids, in the presence of phenyliodine diacetate (PIDA), and polyols. The CO2 produced during the reaction allowed the access to self-blown polyurethane foams through an...

Polyurethane (PU) foams are key players within the large foam market, with applications such as thermal insulating materials, cushioning, protective equipment, etc. With the current regulatory constraints on the use...

Background: Age is a major risk factor for venous thromboembolism (VTE), yet patients aged ≥90 years are under-represented in clinical trials of anticoagulant therapy. The objectives were to describe and compare patient clinical characteristics, treatments, and outcomes (VTE recurrence, bleeding, and mortality) during the first 3 months of anticoa...

Background: Identification of patients with acute symptomatic pulmonary embolism (PE) who are at low-risk for short-term complications to warrant outpatient care lacks clarity. Method: In order to identify patients at low-risk for 30-day all-cause and PE-related mortality, we used a cohort of haemodynamically stable patients from the RIETE regis...

Methyl ricinoleate was functionalized using thiol-ene click chemistry in order to synthesize bio-based comb (co)poly(9-alkyl 12-hydroxystearate)s. The latter were then evaluated as Viscosity Index Improvers in a mineral based lubricant. While most of the poly(9-alkyl 12-hydroxystearate)s investigated behave as thickeners, copolyesters containing 15...

The synthesis of π-conjugated polymers via an environmentally friendly procedure is generally challenging. Herein, we describe the synthesis of divanillin-based polyazomethines, which are derived from a potentially bio-based monomer. The polymerization is performed in 5 min under microwave irradiation without any metallic catalyst, with water as th...

2‐Pentadecyl‐[1,1”‐biphenyl]‐4,4”‐diol (PBD) was synthesized starting from cashew nut shell liquid (CNSL)‐a by‐product of cashew processing industry. A new series of partially bio‐based aromatic (co)polycarbonates possessing biphenylene units and pendant pentadecyl chains was synthesized by solution polycondensation of PBD or varying compositions o...

The association between elevated liver enzymes or FIB-4 (fibrosis index 4) and outcome in patients with venous thromboembolism (VTE) has not been evaluated. Data from patients in RIETE (Registro Informatizado Enfermedad TromboEmbólica) were used to assess the association between elevated liver enzymes or FIB-4 levels and the rates of major bleeding...

We report the use of the DBU-CO 2 switchable solvent system for the direct electrospinning of cellulose. Two cellulose types were investigated, i.e. microcrystalline cellulose (MCC) and cellulose pulp (CP). The morphologies of the obtained cellulose fibers were studied using scanning electron microscopy and optical microscopy. Results obtained show...

Background Venous thromboembolism (VTE) represents a relevant cause of morbidity in patients with solid-organ transplant (SOT), but there are scarce data on the management and outcomes in these patients. Methods RIETE is a worldwide, ongoing observational registry of patients with objectively confirmed, acute VTE. We used the RIETE database to com...

Waterborne isocyanate-free grafted poly(hydroxy urethane)-poly(butyl methacrylate) hybrid dispersions were synthesized by miniemulsion polymerization. Grafting was induced by including methacrylate functionalities in the poly(hydroxy urethane) and was controlled by the degree of functionalization. It is shown that grafting enabled a fine tuning of...

We report the use of the DBU-CO2 switchable solvent system for the direct electrospinning of cellulose. Two cellulose types were investigated, i.e. microcrystalline cellulose (MCC) and cellulose pulp (CP). The morphologies of the obtained cellulose fibers were studied using scanning electron microscopy and optical microscopy. Results obtained showe...

Bicylic carbonates are precursors employed in non-isocyanate polyurethane syntheses, namely polyhydroxyurethanes (PHUs) and, among them, ether-activated biobased diglycerol dicarbonate (DGDC) is widely investigated. Herein, the original separation of DGDC stereoisomers, thanks to a recrystallization procedure, leading to enantiomers having differen...

A VOC-free method for the synthesis of PHU-(meth)acrylic waterborne hybrid dispersions was developed. PHU synthesized by bulk aminolysis of cyclic-carbonate derivatives using bio-sourced vegetable oil-based diamines was dissolved in (meth)acrylate monomers, the solution dispersed in water and polymerized in miniemulsion. Hybrid particles exhibiting...

While organic electronics are ubiquitous in our daily lives, studies dealing with their environmental impact or their sustainability are scarce. Indeed, their preparation often requires hazardous conditions along with multi-step synthesis and purification reactions in order for them to be appropriately fabricated from refined petroleum products. Ne...

Among possible routes towards isocyanate-free PUs, aminolysis of cyclic carbonates leading to polyhydroxyurethanes (PHUs) is one of the most promising pathways. Herein, we describe the solvent-free synthesis of shape memory PHU networks from diglycer-ol dicarbonate through reactive extrusion with varying amounts of primary and secondary triamines,...

This paper describes the synthesis of bio-based methacrylated 12-hydroxystearate glucose (MASG), and its (co)polymerization with methyl methacrylate (MMA) by either free- or RAFT radical polymerizations. The obtained amphiphilic p(MMA-MASG) copolymers self-assembled in water into various morphologies depending on the MASG unit content and glycopoly...

Divanillin was synthesized in high yield and purity using Laccase from Trametes versicolor. It was then polymerized with benzene-1,4-diamine and 2,7-diaminocarbazole to form polyazomethines. Polymerizations were performed under microwave irradiation and without transition-metal-based catalysts. These biobased conjugated polyazomethines present a br...

Enzymatic synthesis of fatty acid glucose esters from different fatty acyl donors are performed via enzymatic catalysis in the presence of Candida antarctica lipase B (CALB), using acetonitrile as the solvent. The acyl donor nature (fatty acid or fatty acid vinyl ester) and structure are varied. Lower reaction rates and lower conversions are obtain...

Fatty acid sugar esters represent an important class of non-ionic bio-based surfactants. They can be synthesized from vinyl fatty acids and sugars with enzyme as a catalyst. Herein, the influence of the solvent, the lipase and the temperature on a model reaction between vinyl palmitate and glucose via enzymatic catalysis has been investigated and t...

Trehalose diesters exhibiting $\alpha$,$\omega$-unsaturation are glycolipids which can be easily polymerized by ADMET (acyclic diene metathesis) polymerization. In this paper, enzymatic esterification was performed to selectively esterify primary hydroxyl groups of trehalose (6 and 6'-positions) with vinyl undecenoate. The vinyl ester was beforehan...

In the context of the development of bio-refineries, glycerol and its derivatives are co-products of the oleochemistry for which new valorization routes must be found. In this study, the polymerizability of divinylglycol (DVG), a symmetrical C-6 glycerol derivative which bears a vicinal diol and two vinyl functions was studied. The reactivity of th...

This paper aimed at obtaining cross-linked polymeric materials of biomass origin. For this purpose one-pot polyesterification of methyl ricinoleate and methyl 12-hydroxystearate using titanium isopropoxide as a catalyst has been performed leading to polyesters known as estolides. The obtained estolides were successfully cross-linked using dicumyl p...

New bio-based diamines were successfully synthesized from vanillin and fully characterized. These amines, methylated divanillylamine (MDVA) and 3,4-dimethoxydianiline (DMAN), were then used as curing agent with epoxy monomers. Epoxy thermosets obtained from these new bio-based amines exhibited promising thermomechanical properties in terms of glass...

As we passed the 20th anniversary of the publication of the 12 principles of green chemistry, the sustainable modification of cellulose, being the most abundant biobased polymer, is certainly worth considering. Many researchers work on an efficient valorization of this renewable resource due to its manifold and promising application possibilities,...

Widely available vegetable oils were readily derivatized into chemically pure ABn-type monomers (n = 2 or 3). Their polymerization led to unprecedented hyperbranched polyesters. Four different AB2/AB3-type monomers bearing one A-type methyl ester and two or three B-type alcohol functions were purposely synthesized via two elementary steps, i.e. epo...

Objective: Overlap exists between the risk factors for coronary artery disease and venous thromboembolism (VTE). However, a paucity of data is available on the incidence of major acute cardiovascular events (MACE) and major adverse limb events (MALE) among patients presenting with VTE. Moreover, it is unknown whether the rate of cardiovascular out...

Replacing toxic isocyanates and petro-based reactants currently employed for PUs synthesis is nowadays a major concern. Among all the possible routes to isocyanate-free PUs, aminolysis of cyclic carbonates, leading to Poly(HydroxyUrethane)s seems to be one of the most promising pathways. Herein, we discuss the added value brought by the reactive ex...

Bio-based aromatic diamines from vanillin substrate were successfully synthesized and characterized. These amines, i.e., methylated divanillylamine (MDVA) and 3,4-dimethoxydianiline (DMAN), were then tested as curing agents for the design of bio-based epoxy thermosets. The epoxy thermosets obtained from these novel vanillin-based amines exhibited p...

This study aims at obtaining cross‐linked polymeric materials of biomass origin. For this purpose, one‐pot polyesterification of methyl ricinoleate and methyl 12‐hydroxystearate using titanium isopropoxide as a catalyst is performed leading to polyesters known as estolides. The obtained estolides are successfully cross‐linked using dicumyl peroxide...

A series of cross-linkable waterborne polyurethanes (WPUs) from a bio-sourced diol was synthesized through the acetone process. WPUs have attracted much interest for coating and adhesive applications as they have low levels of emission of volatile organic compounds. Cross-linking of an obtained polyurethane (PU) film should improve its mechanical p...

Saccharide diesters have been recently shown to be excellent gelator of vegetable oils. In this paper, different fatty acid trehalose diesters were synthesized by a selective enzymatic transesterification performed only on the primary hydroxyl group of the trehalose. The resulting trehalose diesters demonstrated their ability to self-assemble in a...

We report a sustainable and easy approach for the preparation of cellulose-based aerogels from the DBU-CO2 switchable solvent system via a solubilization and coagulation approach followed by freeze-drying. The easy, fast and mild solubilization step (15 min at 30 °C) allows for a rapid preparation procedure. The effect of various processing paramet...

Bio-sourced polycarbonate networks have been synthesized from an alkene-functional fatty-acid based polycarbonate precursor. Cross-linked networks were created using the radical thiol-ene coupling reaction. The resulting polycarbonate materials exhibited versatile properties either influenced by the structure of the cross-linker or the cross-linker...

As we passed the 20th anniversary of the publication of the twelve principles of green chemistry, the sustainable modification of cellulose, being the most abundant bio-based polymer, is certainly worth considering. Many researchers work on an efficient valorization of this renewable resource due to its manifold and promising application possibilit...

Fatty acid sugar esters represent an important class of non-ionic bio-based surfactants. They can be synthesized from vinyl fatty acids and sugars with enzyme as a catalyst. Herein, the influence of the solvent, the lipase and the temperature on a model reaction between vinyl palmitate and glucose via enzymatic catalysis has been investigated and t...

In the context of the development of bio-refineries, glycerol and its derivatives are co-products of the oleochemistry for which new valorization routes must be found. In this chapter, the polymerizability of divinylglycol (DVG), a symmetrical C-6 glycerol derivative that bears a vicinal diol and two vinyl functions was investigated. The reactivity...

This work aims at designing functional biomaterials through selective chemical modification of xylan from beechwood. Acidic hydrolysis of xylan leaded to well-defined oligomers with an average of six xylose units per chain and with an aldehyde group at the reductive end. Reductive amination was performed on this aldehyde end-group to introduce an a...

We introduce a novel isocyanide-based multicomponent reaction, the Passerini four component reaction (P-4CR), by replacing the carboxylic acid component of a conventional Passerini three component reaction (P-3CR) with an alcohol and CO2. Key to this approach is the use of a switchable solvent system, allowing the synthesis of a variety of α-carbon...

A new bio-based biphenylene-containing diisocyanate, namely, 5,5′-diisocyanato-2,2′,3,3′-tetramethoxy-1,1′-biphenyl (BDI) was synthesized starting from vanillic acid – a lignin-derived phenolic acid. A series of new partially bio-based polyimides was prepared by polycondensation of BDI with five commercially available aromatic dianhydrides. Polyimi...

A sustainable metal-free route to urethanes and ureas based on a photocatalyzed oxidative decarboxylation of oxamic acids is described. The reaction includes the in situ generation of an isocyanate from the oxamic acid, using an organic dye as a photocatalyst, an hypervalent iodine reagent as an oxidant and a light source, which trigger the free-ra...

A complete study of the effect of different organocatalysts on the step-growth polyaddition of a five-membered dicyclic carbonate, namely diglycerol dicarbonate, with a poly(ethylene glycol)-based diamine in bulk at 120 °C was first carried out. The reaction was found to be dramatically catalyst-dependent, higher rates being observed in the presenc...

Bio-based epoxy monomers from divanillyl alcohol were successfully synthesized and characterized. These latter, i.e. diglycidylether of divanillyl alcohol (DiGEDVA), triglycidylether of divanillyl alcohol (TriGEDVA) and tetraglycidyl of divanillyl alcohol (TetraGEDVA) were then cured with cyclo-aliphatic diamine (IPDA), employed as hardener. The va...

The direct transesterification of cellulose with high oleic sunflower oil, without any activating steps, was achieved in a DBU-CO2 solvent system to obtain fatty acid cellulose esters (FACEs). Optimization of the reaction parameters (i.e. concentration, temperature, plant oil equivalents as well as reaction time) was performed using microcrystallin...

Fatty acids were used as precursors for the synthesis of photosensitive polycarbonate materials. In order to avoid multistep reactions, a simple and straightforward methodology toward the synthesis of photosensitive monomers has been developed. Hence, a fatty acid–based cyclic carbonate bearing an unsaturation was synthesized and subsequently polym...

In this manuscript, we present an optimization study of the switchable solvent system DBU/CO2 for cellulose solubilization and derivatization via online Fourier Transform Infrared Spectroscopy (FT-IR). By varying temperature, CO2 pressure and solubilization time, we succeeded to achieve cellulose solubilization within 10 to 15 min at 30 °C. Compare...

A rapid and effective dissolution and activation of cellulose was demonstrated by a reversible reaction of CO2 with the hydroxyl groups of the cellulose backbone in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). The dissolved cellulose was subsequently subjected to in situ derivatization with succinic anhydride without the need of any ad...

An FTIR (Fourier Transform InfraRed) microscope combined to a high pressure cell has been used to determine the CO2 uptake in several common elastomers. Both the CO2 sorption and the resulting swelling of the elastomers have been determined as function of pressure (P = 5–15 MPa) at constant temperature (T = 50 °C). A significant quantity of CO2 is...

The present work is dedicated to the design of novel sulfur-substituted cyclic carbonates from thioglycerol, fatty acids and sugar derivatives. In this methodology, a sulfur atom is inserted in β position of 5-membered ring cyclic carbonates via a two-step synthesis including the thiol-ene coupling of thioglycerol on fatty acid derivatives, followe...

Trehalose diesters exhibiting α,ω-unsaturation are glycolipids which can be easily polymerized by ADMET (acyclic diene metathesis) polymerization. In this paper, enzymatic esterification was performed to selectively esterify primary hydroxyl groups of trehalose (6 and 6'-positions) with vinyl undecenoate. The vinyl ester was beforehand obtained by...

Diglycidylether of bisphenol A and isophorone diamine (IPDA) are industrially used for polyepoxide curing. Herein, glycidylated Organosolv lignin (GOL) is cured with diglycidyl ether of bisphenol A and IPDA for intensive studies. Organosolv lignin (OL) is therefore first glycidylated with epichlorohydrin to a material with an epoxy content of 3.2 m...

This manuscript is dedicated to the literature on vegetable oil-based polyurethanes via the isocyanate/alcohol route. A lot of efforts have been made to replace petroleum-based resources. Among renewable resources, vegetable oils present various advantages going from their availability to the large range of possible chemical modifications they perm...

A strategy to convert by isomerization‐hydroboration‐oxidation reaction the internal double bond of oleic acid to a terminal alcohol function, leading to linear long‐chain α,ω‐difunctional substrates has been investigated. Using this strategy, oleic acid‐based AB‐ and AA‐monomers were prepared and characterized by FTIR‐ATR and NMR spectroscopy. The...

Bio-based primary amines obtained from the corresponding alcohols via nitrile intermediates and their subsequent polymerizations with cyclic carbonates are described. Nitrile compounds were synthesized under mild aerobic oxidation of primary aliphatic alcohols. CuI, bipyridine and TEMPO were used as a catalytic system, in the presence of aqueous am...

Activated 5-membered cyclic carbonates were prepared from glycerol and fatty acid derivatives. Ester and ether moieties were introduced in β position to the cyclic carbonate, in order to enhance its reactivity towards amines. 1H NMR kinetic investigation of the aminolysis of these cyclic carbonates demonstrated a higher reactivity compared to the o...

Widely available vegetable oils were readily derivatized into chemically pure ABn-type monomers (n = 2 or 3). Their polymerization led to unprecedented hyperbranched polyesters. Four different AB2/AB3-type monomers bearing one A-type methyl ester and two or three B-type alcohol functions were purposely synthesized via two elementary steps, i.e. epo...

A laccase-catalyzed process was developed to prepare, selectively, in high yield, dimers of lignin-based phenolic compounds without any purification. The influence of experimental parameters such as laccase loading, nature of solvent and the presence of oxygen on the conversion of vanillin was investigated. After the dimerization, the product obtai...

Four biphenyl monomers derived from vanillin or eugenol were synthesized and polymerized by the ADMET methodology. The biphenyl compounds were produced by enzymatic dimerization of 2-methoxy-4-methylphenol, methyl vanillate, vanillin and eugenol. Further chemical modifications of the obtained dimers such as transesterification, Wittig reaction or a...

Nowadays, the synthesis of (semi)aromatic polymers from lignin derivatives is of major interest, as aromatic compounds are key intermediates in the manufacture of polymers and lignin is the main source of aromatic biobased substrates. Phenols with a variety of chemical structures can be obtained from lignin deconstruction; among them, vanillin and...

Two symmetrical biphenyl monomers derived from vanillin, a methylated divanillyl diol and a methylated dimethylvanillate dimer, were synthesized and employed as (co)monomers for the design of renewable (semi)aromatic polyesters. The reactivity in polytransesterification of these new monomers was investigated in bulk in the presence of various catal...

The invention relates to a compound of formula (I) wherein and A1 and A1' are independently from each other a linear or branched alkylene radical comprising from 1 to 20 carbon atom(s); A2 is in particular a linear or branched alkylene radical comprising from 1 to 200 carbon atom(s); A3 is H or a linear or branched alkyl radical comprising from 1 t...

Polylactide (PLA) is one of the most mature biobased and biocompostable plastics currently in the market. Despite its mechanical properties comparable to the ones of some mainstream petroleum-based thermoplastics (PS, for instance), PLA inherent brittleness and heat sensitivity are issues for its full industrial development. In this study, we inves...

Polyurethane-urea latex particles were synthesized by miniemulsion polyaddition of fatty acid-based diol derivatives and isophorone diisocyanate. The influence of the solid content, the surfactant and the hydrophobic agent was studied. Stable monodispersed latex particles with diameters around 200-300nm were obtained with solid content up to 50wt%,...

Selective catalytic carbonylation of the trisubstituted double bond of citronellic acid is enabled via an isomerization–functionalization approach. Alkoxycarbonylation with [{1,2-(tBu2PCH2)2C6H4}Pd(OTf)2] as a catalyst precursor occurs with >97% selectivity for the terminal diester dimethyl-3,7-dimethylnonane-dioate. This prevails much over the typ...

(Bis) 6-membered cyclic carbonates were prepared from methyl 10-undecenoate, which is produced from ricinoleic acid, a main constituent of castor oil. Kinetics on these new fatty acid-based 6-membered cyclic carbonates revealed that they are much more reactive than their homolog 5-membered ones (30 times). Poly(hydroxyurethane)s (PHUs) were then sy...

Fatty acid-based bis-cyclic 5-membered carbonates containing amide linkages were prepared from methyl 10-undecenoate. The reaction in bulk of these bio-based carbonates with a series of di-amines led to poly(hydroxyurethane amide)s with molar masses up to 31000 g mol−1. As expected, the so-formed bio-based thermoplastic poly(hydroxyurethane)s exhib...

Castor oil and vernonia oil platforms were used to synthesize two linear and branched α,ω-diene monomers. ADMET copolymerization conducted in bulk yielded a series of copolyesters with various degrees of branching with respect to the feed ratio between the two α,ω-dienes. After hydrogenation, these copolyesters showed thermo-mechanical properties i...

A new route to α,ω-diene urethane monomer is proposed by converting 10-undecenoic acid into the corresponding acyl azide, followed by urethanization with 10-undecenol. ADMET polymerizations of this α,ω-diene urethane monomer as well as other bio-based α,ω-dienes bearing various organic functions (ester, carbonate, ether, amide) were carried out in...

During analysis of pure isoprene by chromatography/mass spectrometry (GC-MS) using a programmed temperature vaporization (PTV) inlet, the presence of several isoprene dimers was detected in the total ion chromatograms (TICs). This study intends to determine the part of the instrument where dimerization occurs and the relative importance of the dime...

Nowadays the use of vegetable oils as polymer precursors is the subject of growing interest in the academic and industrial communities. Many synthetic pathways can be pursued from natural vegetable oils to yield different functionalized derivatives – also called synthons – and polymers, such as polyesters, polyurethanes, polyamides, etc. Herein, we...

Procédé de synthèse de copolymères à blocs comprenant des monomères vinyliques polaires et apolaires en présence: (a) d'un catalyseur comprenant un métal, au moins un ligand oxydant et au moins un ligand complexant, électrodonneur et monodentate, et (b) d'un composé générateur de radicaux libres. L'invention concerne un procédé de synthèse de copol...