Fired clay bricks using agricultural biomass wastes: Study and characterization

The main objective of this study is to investigate the effects of the incorporation of renewable pore-forming agents on the properties of fired bricks. Different additives have been studied (wheat straw, sunflower seed cake and olive stone flour) at different grinding and incorporation rate. Physical properties such as linear shrinkage, loss on ignition, bulk porosity, water absorption and bulk density have been measured. Mechanical and thermal performances have also been characterized. The incorporation of 4wt.% of sunflower seed cake, with the lowest grinding, leads to the best compromise between mechanical and thermal results compared to the reference brick

From crops to products for crops: preserving the ecosystem through the use of bio-based molecules

In a context of dwindling oil reserves and environmental pressures, the chemical industry needs to innovate by developing new processes for producing bioproducts from raw plant materials. Unsaturated fatty acids from vegetable oils constitute a highly promising renewable resource that can be used to diversify productions, decreasing reliance on petroleum. A starting material rich in oleic acid has been obtained through the selection of high-oleic sunflower varieties and enzymatic hydrolysis of the oil they produce. The double bonds of this unsaturated raw material have been cleaved in green oxidizing conditions involving a biphasic lipophilic-aqueous system including hydrogen peroxide as an oxidant and a peroxo-tungsten complex Q3 {PO2[WO(O2)2]4} as a phase-transfer catalyst (PTC) and co-oxidant. This PTC efficiently transferred oxygen to the substrate in the lipophilic phase. A mono-acid (pelargonic acid) and a di-acid (azelaic acid), with shorter, unusual hydrocarbon chains not present in the natural state, were synthesized and purified through an intensive process. Pelargonic acid was then formulated as an environmentally friendly biocontrol agent for weeds. We extended this green process of oxidative scission to other fatty acids and derivatives, to obtain other short-chain acids with diverse potential applications. This production chain (crops, reaction and purification processes, products, applications) is based on a sustainable development strategy. Dans un contexte de diminution des réserves fossiles et de pressions réglementaires et environnementales, l’industrie chimique tend à innover en développant de nouveaux procédés pour la production de bioproduits d’origine végétale. Les acides gras insaturés d’une huile végétale constitue une ressource renouvelable prometteuse qui peut être utilisée pour diversifier les productions et réduire la dépendance vis-à-vis du pétrole. Dans cet article, une matière première riche en acide oléique a été obtenue par l’hydrolyse enzymatique de l’huile de tournesol hautement oléique, obtenue par sélection variétale. Les doubles liaisons de cette matière première insaturée ont été clivées dans des conditions oxydantes impliquant un système biphasique aqueux-lipophile, avec le peroxyde d’hydrogène comme oxydant et le complexe peroxo-tungtène Q3{PO2[WO(O2)2]4} comme catalyseur de transfert de phase (CTP) et co-oxydant. Ce CTP a permis d’assurer un transfert efficace vers le substrat en phase lipophile. Un mono-acide (acide pélargonique) et un di-acide (acide azélaïque) à chaînes impaires plus courtes, peu présentes à l’état naturel, ont été ainsi synthétisés et purifiés grâce à un procédé intensifié. L’acide pélargonique a été formulé en tant qu’agent de biocontrôle écocompatible. Ce procédé vert de scission oxydante a été appliqué à d’autres acides gras et à leurs dérivés pour obtenir de nouveaux acides à chaînes courtes ayant différentes applications potentielles. Cette filière de production (culture, procédés de transformation et de purification, produits et leurs application) est basée sur une stratégie de développement durable

Development of porous fired clay bricks with bio-based additives: Study of the environmental impacts by Life Cycle Assessment (LCA)

The incorporation of bio-based pore-forming agents, from either agricultural (wheat straw – WS and olive stone flour – OSF) or chemical (glycerol carbonate – GC and dimethyl carbonate – DMC) origins, into clay formulations, has been investigated. Fire clay porous tablets have been manufactured at laboratory scale and characterized through physical, mechanical and thermal properties. An increase of 7.2% of the porosity correlated to a decrease of 7.0% of the thermal conductivity was measured for the best samples. The environmental impacts of these formulations have also been examined through a Life Cycle Assessment (LCA) using the ReCiPe v1.10 method. It was noticed that the incorporation of pore-forming agents led a decrease of about 15–20% of all the studied impact categories. The advantage of the use of bio-based additives in clay bricks was then confirmed from both performance (lighter material with a better thermal insulation) and environmental points of view

Graft copolymerization of hydroxyethyl cellulose with solketal acrylate: Preparation and characterization for moisture absorption application

In this work, we reported the preparation of a novel biomaterial, by graft-polymerization of 2-2-dimethyl-1-3-dioxolan-4-yl methyl acrylate (solketalacrylate, DMDMA) on hydroxyethyl cellulose (HEC) using KPS as initiator. Several experiments were performed to found the optimum conditions for the preparation of this biopolymer, by varying the time of the reaction as well as the initiator and the monomer ratio. Results showed that the highest grafting yield was 25%, obtained after 72 minutes at 65 °C, using THF as solvent. The structure of the grafted copolymer was confirmed by X-ray diffraction patterns which showed, besides the characteristic peaks of HEC at 2θ = 31.74° and 44.63° a new peak at 2θ = 30.72° related to an organized structure of the grafted polymer on the HEC backbone. The DSC analysis showed a single glass transition temperature Tg, intermediate between the corresponding values for HEC and neat poly(solketal acrylate). Moreover, the grafted biomaterial presented two-fold more moisture absorption ability by comparison with HEC, making this new synthetic biomaterial highly promising for dryness applications. In our knowledge, the synthesized monomer: 2-2-dimethyl-1-3-dioxolan-4-yl methyl acrylate, (solketal acrylate, DMDMA), has never been grafted on the HEC backbones before that is what makes the novelty of the present work

Synthesis of graft -copolymers from palm cellulose and solketal acrylate and their characterization

he use of partially biobased monomers to functionalize palm cellulose via graft-copolymerization was explored. The aim of this work is to recycle a waste, the leaves of palm trees, which are abundant in North African countries in order to obtain novel cellulose derivatives having interesting physico-chemical properties. Furthermore, the monomer that was used for the graft-copolymerization was synthesized from a biobased synthon, glycerol. The synthesis of graft-copolymers from cellulose and (2,2-dimethyl-1,3-dioxolan-4-yl)methyl acrylate (solketal acrylate, DMDMA) was studied to determine the optimal conditions for grafting. The maximum grafting weight gain was 27% obtained after 72min of reaction at 65°C with 6.4mmol KPS/eq OH and 1.51mol DMDMA/eq OH. THF, used as dispersion solvent, hinders the homopolymerization side-reaction by creation of terminating radicals. FTIR spectroscopy confirmed the grafting of monomers to cellulose and X-ray diffraction revealed an organized structure of the side-chains. Thermogravimetry showed that the grafting could not confer a higher thermal stability to cellulose (loss of 35°C in the decomposition temperature). Even though partial melting was observed when thermopressed, DSC analysis could not show a neat glass transition temperature but rather multiple exothermal peaks attributed to side-chains reorganization. Thermopressed grafted samples showed improved mechanical properties compared to palm cellulose

Synthesis of new cellulose ethers using Suzuki–Miyaura reactions

Cellulose ethers are functionalized biopolymers that are industrially produced through drastic conditions employing gaseous reactants with a high risk of industrial accident. The cellulose ethers that are commercially available generally bear short carbon-chains. In this work, an alternative method using non-gaseous chemicals is proposed. It relies on the use of the Suzuki–Miyaura reaction employing mild, moisture- and air-stable conditions. Relatively innocuous reagents are used for this step, which allows the formation of a wide range of cellulose ethers bearing various functional groups with different chain-length

LCA case study: comparison between independent and coproduction pathways for the production of ethyl and n-butyl acetates

The production of ethyl acetate and n-butyl acetate was investigated through two different pathways: either by independent reactions or by coproduction. In the coproduction pathway, the n-butyl acetate was produced by reusing the by-products of the synthesis of ethyl acetate. This study provides a comparison of the environmental impacts of these two pathways using a life cycle assessment (LCA). A discussion about the use of LCA on chemicals and its challenges was also developed

Vers la synthèse totale de la paulitine. Etude de nouvelles réactions de métathèse.

THE AIM OF THIS WORK WAS INITIALLY THE TOTAL SYNTHESIS OF PAULITINE. THE RESULTS OBTAINED LEAD US TO STUDY THE ENYNE-METATHESIS MECHANISM IN MORE DETAIL, IN ORDER TO OBTAIN THE A-B BICYCLE OF THE TARGET MOLECULE. IT WAS THEN HIGHLIGHTED THAT, FOR ENYNES WITH A TERMINAL ALKYNE AND AN OXYGEN ATOM AT THE PROPARGYLIC POSITION, THE RUTHENIUM CARBENE FIRST ! REACTS WITH THE ALKYNE. STERIC HINDRANCE AT THE PROPARGYLIC PO! SITION S EEMS TO INFLUENCE STRONGLY THE YIELD OF THE METATHESIS: CYCLIZATION IS MUCH EFFICIENT WHEN IT DECREASED. A DESMETHYL PRECURSOR OF THE TARGET BICYCLE WAS THEN OBTAINED IN SEVEN PERCENTS OVER EIGHT STEPS. ASYMMETRIC SYNTHESIS OF THE BICYCLE AS WELL AS FORMATION OF ALPHA-METHYLENE-GAMMA-BUTYROLACTONES WERE THEN STUDIED.PARALLEL TO THIS WORK, A NEW METHODOLOGY WAS DEVELOPED FOR THE METATHESIS OF ALLYLIC AMINO COMPOUNDS, WHICH ARE GENERALLY POOR METATHESIS-PARTNERS. THE USE OF BORON-BASED LEWIS ACIDS, ALLOWED TO CLEANLY OBTAIN COUPLING PRODUCTS. THIS NEW METHOD GAVE ACCESS TO A WIDE RANGE OF FUNCTIONALIZED OLEFINS, IN GOOD YIELDS, WHEN REACTIONS WERE LED IN REFLUXING TOLUENE FOR TWELVE HOURS, USING FIVE PERCENTS OF HOVEYDA-BLECHERT CATALYST AND ONLY ONE EQUIVALENT OF METATHESIS-PARTNER.CES TRAVAUX DE THESE ONT INITIALEMENT EU POUR OBJET LA SYNTHESE TOTALE DE LA PAULITINE. LES RESULTATS OBTENUS NOUS ONT AMENES A MENER UNE ETUDE CONCERNANT LE MECANISME DE LA METATHESE ENE-YNE VERS LA FORMATION DU BICYCLE A-B DE LA MOLECULE CIBLE. CETTE ETUDE A ALORS PERMIS DE METTRE EN EVIDENCE QUE, LORS DE LA RCM D'ENYNES COMPORTANT UN ALCYNE VRAI ET UN ATOME D'OXYGENE EN ALPHA DE LA TRIPLE LIAISON, LE CARBENE DU RUTHENIUM ATTAQUE L'ALCYNE EN PREMIER. L'ENCOMBREMENT STERIQUE EN POSITION PROPARGYLIQUE SEMBLE FORTEMENT INFLUENCER LE RENDEMENT DE LA METATHESE: LA CYCLISATION EST PLUS EFFICACE LORSQUE CELUI-CI DIMINUE. UN PRECURSEUR DESMETHYLE DU BICYCLE CIBLE A ALORS PU ETRE SYNTHETISE AVEC UN RENDEMENT DE SEPT POURCENTS SUR HUIT ETAPES. LA SYNTHESE ASYMETRIQUE DU BICYLE AINSI QUE LA FORMATION DE MOTIFS ALPHA-METHYLENE-GAMMA-BUTYROLACTONES PRESENTS DANS LA PAULITINE ONT ENSUITE ETE ETUDIEES.PARALLELEMENT A CE TRAVAIL DE SYNTHESE, UNE NOUVELLE METHODOLOGIE A ETE DEVELOPPEE POUR LES METATHESES DE COMPOSES AZOTES ALLYLIQUES, HABITUELLEMENT DELICATES. L'UTILISATION DE BORANES, EN TANT QU'ACIDE DE LEWIS, OFFRE DE NOUVELLES CONDITIONS, PERMETTANT D'OBTENIR PROPREMENT DES PRODUITS DE COUPLAGE. CETTE NOUVELLE METHODE DONNE ACCES A DES OLEFINES DIVERSEMENT FONCTIONNALISEES PAR UN GROUPE AZOTE AVEC DE BONS RENDEMENTS, LORSQUE LA REACTION EST EFFECTUEE AU REFLUX DU TOLUENE, PENDANT DOUZE HEURES, EN PRESENCE DE CINQ POURCENTS DE CATALYSEUR D'HOVEYDA-BLECHERT ET D'UN SEUL EQUIVALENT DE PARTENAIRE DE METATHESE

Vers la synthèse totale de la paulitine (étude de nouvelles réactions de métathèse)

PALAISEAU-Polytechnique (914772301) / SudocSudocFranceF

Development of construction bricks using bio-based pore-forming agents

National audienc