Lubrifiants et environnement

As figures show, volumes of lost lubricants in Europe like in most of industrial countries represent a threat for the environment and for the human health. Numerous activity fields are concerned through equipment involved in transports, in construction, in mechanical industry, in forest harvesting or in agriculture… The spread of lubricants in the environment affects different parts of the natural medium (soils, underground waters, rivers…), which explains the difficulty to select analytic methods assessing the real environmental impact of these products. The most usual analyses provides degradation rates of the substance in contact with microorganisms, doses of non-toxicity or measures regarding to the oxygenation rate of waters. It is important to select the most adapted method according to the context. For a few years, vegetable based lubricants have been considered as a reliable solution to combine technical performances and ecocompatibility characteristics. These meet criteria defined in ecolabels or other classifications concerning several categories of biolubricants. National and european programs aiming at technology transfer allowed to measure and compare the ultimate biodegradability in liquid and in soil for hydraulic fluids. The results obtained show an environmental gain for biolubricants included after a 1,000 hours operation period

Effect of catalytic conditions on the synthesis of new aconitate esters

Sugar cane is a crop which generates large amounts of biomass and a juice rich in highvalue natural molecules. After extracting sugar from the juice, the recovering of various compounds such as organic acids contained in molasses could contribute to increase the competivity of the sugar industry. Therefore, according to the biorefinery approach, we propose to study the chemical conversion of one of these acids, the aconitic acid, by esterification reactions. A new series of aconitate esters have been synthesized by combining aconitic acid and alcohols from natural origin. The effects of experimental conditions have been investigated and have shown that the type of catalysis has a significant effect on the selectivity. Kinectics have thus been performed to determine the best conditions to synthetize enriched compositions in esters. Homogeneous catalysis generates the highest yield in triester. Heterogeneous catalysis(macroporous resins) is prefered for the production of monoesters while catalysis assisted by ionic liquid is adapted to prepare mainly diesters. Green indicators have been discussed according to the calculations performed. The resulting polyfunctional esters are totally biosourced molecules and have a great potential as bioproducts for different applications

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

Integrated process for extraction and formulation in emulsions of active molecules from fresh passion fruits (Passiflora edulis Sims)

Intensified green processes were investigated to extract several classes of active molecules from fresh purple passion fruits, and to prepare emulsions directly by extrusion for the fruit comprehensive utilization. A thermo-mechanical treatment was carried out through a discontinuous process from the edible part and through a continuous process by twin-screw extrusion using the whole fruit. Only mechanical energy was applied to the materials to generate a liquid fraction (filtrate) and a solid residue. Lipid contents of the obtained filtrates ranged from 0.5 to 2.6 g/100 g close to the extractible lipophilic part. Polyphenols extraction was improved when using the whole fruit and with the addition of water in extrusion. In-situ emulsions with droplets sizes between 2 and 8 μm were obtained. Emulsions obtained after extrusion showed an enhanced stability. This way represents a green alternative method to solvent extractions applied to the different parts of the fruit, and leads to bio-based emulsions enriched in vegetable oil, natural antioxidants and emulsifiers, such as phospholipids, proteins, polysaccharides, pectins and polyphenols

Facile synthesis of nanoparticles of the molecule-based superconductor κ-(BEDT-TTF)2Cu(NCS)2

Well-dispersed roughly spherical nano-objects of the molecule-based superconductor κ-(BEDT-TTF)2Cu(NCS)2 have been prepared in an organic solution by using an easy synthetic route. Long alkyl-chain aconitate esters have been used as growth controlling agents. Nano-objects exhibiting sizes in the 35–120 nm range are made of aggregated individual smaller nanoparticles ranging from 3 to 10 nm. Nanoparticle powders have been studied by X-ray diffraction, high resolution electron microscopy and atomic force microscopy in the conductivity mode. Résumé : Des nano-objets sphériques et bien dispersés du supraconducteur moléculaire κ-(BEDT-TTF)2Cu(NCS)2 ont été préparés en solution organique à l'aide d'une méthode de synthèse relativement aisée. Des aconitates à longue chaîne alkyle ont été utilisés comme régulateurs de croissance. Ces nano-objets de taille comprise entre 35 et 120 nm sont constitués de petites particules dont le diamètre individuel est de l'ordre de 3 à 10 nm. Les poudres nanoparticulaires ont été étudiées par diffraction des rayons X, par microscopie électronique à haute résolution et enfin par microscopie à force atomique en mode conducteur

Semi‐Siccative Oils and Bioactive Fractions Isolated from Reunion Island Fruit Co‐Product: Two Case Studies

Semi-Siccative Oils and Bioactive Fractions Isolatedfrom Reunion Island Fruit Co-Product: Two Case StudiesAlice Delvar, Pascale de Caro,* Yanis Caro,* Alain Shum Cheong Sing, Rudy Thomas,and Christine RaynaudThis paper focused on the use of agro-industrial wastes of strawberry guava (Psidiumcattleianum) and passion fruit (Passiflora edulis) generated by the agriculturalindustry on Reunion Island, according to two routes: extraction of semi-siccative oilsfrom the seeds and extraction of bioactive compounds from residual pulp and peels.Oil content, fatty acid, carotenoids, tocopherol, and sterol concentrations aredetermined in the seed oils obtained by four different extraction processes usingSoxhlet extraction, extraction by hexane and ethanol, mechanical pressing andsupercritical-carbon dioxide (SC-CO2) extraction. The oil extraction yields ranged from15 to 30% w/w for strawberry guava and passion fruit, respectively. Both oils areclassified as semi-siccative and had a similar total unsaturated fatty acid content(88%) with a prevalence of linoleic acid (70–78%). High contents in phytosterols andinα-tocopherol are particularly detected in strawberry guava oil. The antioxidantactivities of the bioactive compounds extracted by water and ethanol from pulp andpeels are characterized byα,α-diphenyl-β-picrylhydrazyl (DPPH) test. After purificationon polymeric resin, significant antioxidant activities are recorded (half maximalinhibitory concentration (IC50) from 11 to 50 g L-1) and are related to polyphenolcontents (20.7 to 42.5 g gallic acid equivalents (GAE)/100 g dry extract).Practical Applications: There is a great interest on the use of tropical fruit wastesbecause of their large availabilities. Strawberry guava and passion fruit are often usedin the food industry, for juice and jam production. The seeds, pulp, and peel residuesare in fact a by-product of their industrial processing, which should be valuablyprocessed instead of just throwing away. We can state that the extracted seed (richin polyunsaturated fatty acids) of strawberry guava and passion fruit can be used inthe industrial production of emulsions, paints, and varnishes. Within the positiveaspects of the study, one can also distinguish the use of these tropical fruit by-products as beneficial sources of many valuable bioactive compounds, for example,carotenoids, tocopherols, phytosterols, and especially polyphenols, for functionalformulations. Moreover, it may be the experimental basis for further developmentand use in food industr

Effect of Oils Categories on the Distribution of Polycyclic Aromatic Hydrocarbons and Derivatives in the Environment

Context and objective: The Migr’Hycar research project was initiated to provide decisional tools for risks connected to oil spill drifts in continental waters. This paper focuses on the distribution of polycyclic aromatic hydrocarbons (PAHs) from oils in water, air and oil slicks. Material and methods: Six petroleum oils covering a representative range of commercially available products were tested. Dynamic tests at laboratory scale were performed to study 41 PAHs and derivates, among them 16 EPA priority pollutants. Water soluble fraction protocol, stir bar sorptive extraction (SBSE) and high performance gas chromatography mass spectrometry (HPGC-MS) was used. Limit of quantification were lower than 1 ng.L-1 for each compounds. Results: A large variation in composition of the water soluble fraction depending on oil type and mixing time has been highlighted. Results have shown that evaporation is the primary mechanism of PAHs loss from spilled oil. The subsequent fate of hydrocarbons deposited in surface water is further influenced by volatilisation behaviour because of possible slick loss to the atmosphere. The water soluble fraction remains very low and is dominated by low molecular weight PAHS (e.g. naphthalenes)

Dynamic Behavior of Polycyclic Aromatic Hydrocarbons and Their Derivatives after Oils Spill in Water

Within the framework of Migr’Hycar research project, the fate of oil spill was studied with the aim to characterize their physical-chemical behaviour. For this purpose, seven petroleum oils com- mercially available were tested and the distributions of the water soluble components were deter- mined according to two experimental devices; laboratory conditions and pilot conditions in Pollu- drome. In the dissolved fraction, 41 polycyclic aromatic hydrocarbons and their derivates were quantified, among them are 16 EPA priority pollutants. A coupling of the stir bar sorptive extrac-tion method and high performance gas chromatography mass spectrometry were used. Analyses showed that naphthalenes series constitute the major part of the water soluble fraction from fresh oils. In fact, light and heavy molecules have different contributions to solubilization kinetics. From the results, a linear correlation was established between the density of oils and the times of max-imum solubilization. Moreover, the effect of 10% ethanol in gasoline was observed on the profile of solubilized PAHs in water. Kinetic patterns obtained with Polludrome showed the influence of surface water/oil ratio (WOR) on the volatilization process. Compared to laboratory conditions, the dynamic conditions of Polludrome led to an enhanced evaporation process, thus shifting the solubility peak

Nanoparticles of tetrathiafulvalene chloride derivatives grown in the presence of amphiphilic molecules

The work described in this paper is directed towards the electrosynthesis of TTFCl0,77 as spherical nanoparticles by using amphiphilic molecules, behaving as growth-controlling agents. The morphology and the size distribution of the particles were analyzed using transmission electron microscopy and the resulting powders were characterized by infrared and Raman spectroscopy along with X-ray diffraction. In the presence of dodecylamine, electron micrographs evidenced spherical and relatively well-dispersed nanoparticles exhibiting a mean diameter of about 10 nm. However, in the presence of N-octylfurfurylimine, a mixture of nanoparticles and sticks were formed. The best results in terms of smallness of particles size and narrowness size distribution were obtained in the presence of 1-octanamine, N-(2-thienylmethylene). Spherical nanoparticles exhibiting sizes in the 4–12 nm range with an average size of about 8 nm were observed. The nanoparticles powder exhibited a room temperature conductivity of about 0.01 S.cm–1

Molecular conductors as nanoparticles in the presence of long-chain alkyl imidazolium salts or amphiphilic molecules

Nanoparticles of two molecule-based conductors, namely TTF·TCNQ and TTF[Ni(dmit)2]2, have been prepared in organic solution in the presence of ionic or nonionic species bearing a long-chain alkyl group, acting as growth-controlling agents. The size, morphology, and state of dispersion of the nanoparticles depended on the nature of the growth-controlling agent and the reaction temperature. In the presence of a long-chain alkyl-based ionic liquid at −50 °C, electron micrographs evidence that TTF·TCNQ nano-objects are frequently elongated, whereas TTF[Ni(dmit)2]2 nanoparticles are aggregated. In the presence of a neutral long-chain alkyl-based imine at room temperature, nanoparticles are spherical (mean diameter <20 nm) and well dispersed. Vibration spectra evidence that the amounts of charge transfer for TTF·TCNQ and TTF[Ni(dmit)2]2 as nano-objects are very similar to those for the same phases as bulk materials. According to the thermoanalytical investigations, the prepared nanoparticles are stable thermally up to approximately 200 °C, and their decomposition is generally a multi-step process. Their heat treatment results in various sulfur-containing volatiles (CS2, SO2, H2S); moreover, HCN is also detected in the case of nitrogen-containing molecules (TCNQ)