(Text in French) Eco-sustainable chemistry in Rennes: from biomass and abundant, non-noble metals in catalysis to pertaining industrial applications. Over the past two decades, the Rennes Institute of Chemical Sciences has been strongly committed to the transition of chemistry towards a more eco-sustainable and environmentally friendly approach, particularly in the field of biomass utilization and the development of more eco-friendly catalytic methodologies – notably through the use of non-precious metals or processes that are more economical in terms of atom and energy consumption. This article illustrates this commitment through a selection of representative examples, many of which have led to industrial applications.

The mechanical response of plasticized thin PVC films under a modulated optical radiation pressure excitation is investigated as a function of the plasticizer content. A resonant behavior with different quality factor depending on the plasticizer content is investigated. The higher the content, the larger the resonant width. A significant thinning of the film is observed, whatever the plasticizer content. The surface tension of the air/solid interface is extracted and shown to hardly vary. The loss factor which is known as the ratio of dissipated energy to stored energy is, on the other hand, dependent on the plasticizer content. In particular, the optical studies reveal that all the energy is always stored at the film interfaces with a dissipation described by the well-known loss factor E′′ of the Young’s modulus.

Nitroglycerin (NG) is a high explosive that is difficult to handle in its liquid form, where the entrapment of gaseous NG bubbles results in its high sensitivity to impact (<0.25 J). NG-based materials are traditionally prepared by complex mixing processes where desensitisation is of major concern. Instead of using a mixing procedure here we demonstrate the successful synthesis of dynamite-like materials by using a single step bottom-up approach to form a polymeric host matrix (PM) for NG from a solution which contains the explosive and the matrix precursors. For this purpose, an epoxidized vegetable oil mixed with nitroglycerin (oil to NG mass ratio of 60/40) is polymerized at 100 & DEG;C for 30 h by using glutaric acid as crosslinking agent. No degradation of NG under these conditions is observed. The activation energy of NG desorption from the PM (51.9 kJ/mol) is of the same order of magnitude as the one reported in literature for a double-base powder (81.9 kJ/mol). An accelerated NG desorption is observed as temperature increases. This can be attributed to a slow diffusion mechanism of the explosive from the volume to the surface of the material, where it evaporates. The ignition of NG/PM in air by an open flame leads to a self-sustained combustion, in which a part of nitroglycerin decomposes in the polymer matrix. Conversely, NG/PM monolithic and granular loads are not ignited by the explosion of the primer in a 9 mm calibre casing. The shockwave released by a detonator on a small NG/PM cylindrical charge (& AP;1.5 g) does not detonate it, but only makes it deflagrate. Our results show that this novel single-step synthesis of NG trapped in a polymeric matrix is a very effective approach for desensitizing it to any form of stress.

The treatment of a synthetic polluted gas containing seven volatile organic compounds (VOCs) was studied using a pilot plant in real industrial conditions. The process combined VOC absorption in silicone oil (PolyDiMethylSiloxane, i.e., PDMS), a biological regeneration of the PDMS in a two-phase partitioning bioreactor (TPPB), and a phase separation including settling and centrifugation. The TPPB was operated at a water/PDMS volume ratio of 75/25. The VOCs treatment performance was efficient during the entire test, corresponding to 10 PDMS regeneration cycles. The analysis of the content of the aqueous phase and PDMS confirmed that VOCs are progressively degraded until mineralization. The nitrogen consumption and the characterization of the microorganisms highlighted possible anoxic functioning of the biomass within the first decanter. Moreover, although the absorption and biodegradation performances were very satisfactory, the separation of all phases, essential for the PDMS recycling, was problematic due to the production of biosurfactants by the microorganisms, leading to the formation of a stable emulsion and foaming episodes. As a consequence, the packed column showed slight fouling. However, no significant increase in the pressure drop of the packed bed, as well as no significant impact on VOC absorption efficiency was observed.

Within the prospect to develop a more sustainable solution for the membrane fabrication sector, this work aims to investigate a new combination of bio-based materials, including a polyhydroxyalkanoate (PHA) as a polymer and Cyrene™ as a solvent, for the phase inversion process. The herein studied poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) is a microbial biopolymer with excellent biocompatible, biodegradable and solvent resistance properties; while Cyrene™ is a non-toxic, biodegradable and renewable alternative to most of the traditionally used polar aprotic solvents. Several parameters of the phase inversion process were studied in order to identify the different membrane microstructure possibilities and thus their final performances. The various studied process parameters include the evaporation time before coagulation, the use of different traditional and green additives, the concentration of polymer and additives into the dope solution and the molecular weight of the additives. Polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and an epoxidized broccoli vegetable oil (EBO) were successfully used as pore former agents for these membranes. Developed membranes were fully characterized in terms of morphology, topography, surface wettability, pore size, porosity, thermal degradation, mechanical resistance and stability. After all, membranes exhibiting different architectures (from porous to dense) were obtained. In order to prove their applicability, dense membranes were finally successfully applied in pervaporation (PV) for the separation of an organic/organic azeotropic mixture.

Biological treatments are used in gas treatment when containing Volatile Organic Compounds (VOC). Key factor to enhance treatment efficiency is to maximize mass transfer from gas to liquid. VOCs can be removed from the gas flow by absorption in a separate gas-liquid contactor before entering a Two-Phase Partitioning Bioreactor (TPPB) (Two-stage unit). The Non-Aqueous Phase Liquid (NAPL), a silicone oil in this study, is able to solubilize large amounts of hydrophobic VOCs while avoiding toxicity effects on the microorganisms. The aim of this study is to provide a designing tool for the degradation process occurring in the TPPB. Simulations considering mass transfer coupled with biodegradation kinetics were considered when investigating the TPPB mechanisms. A single VOC (toluene) was first taken as a reference to assess the accuracy of the model in comparison with experimental results. A mixture of seven VOCs (toluene, m-xylene, 1,3,5 trimethylbenzene, nheptane, ethyl acetate, methyisobutylketone and isopropyl alcohol) presenting a wide range of hydrophobicity was then implemented in the model considering no interaction regarding their biodegradation. Degradation kinetics of the mixture (representing an actual exhaust gas from an industrial plant) were compared with experimental results. The developed model tends to highlight that modeling results are closed to experimental results. The results delivered by the model shows that mass transfer, through the "kLa" value, is a key parameter to enhance efficiency of NAPL renewal by biological regeneration.

Thermoset polyesters are prepared from epoxidized waste frying sunflower oil (ESO), commercially available epoxy compounds and glutaric acid. Influence of the nature and concentration of bi- and trifunctionnal epoxy compounds on mechanical properties is studied. Static and dynamic mechanical tests are performed. The molar amount of commercial epoxy compounds used ranges from 20% to 80% regarding the molar amount of ESO. It enables to obtain thermosetting polyesters with glass transition temperatures ranging from 6 degrees C to 102 degrees C, as well as storage modulus ranging from 8 GPa to 14 GPa. 40% of trifunctional epoxy compound and 60% of commercial epoxy compound are found to be the best compromises between bio-based content and mechanical properties. Furthermore, shape memory and vitrimer behavior of those epoxy-acid based networks with 60% of commercial epoxy compounds are evaluated both qualitatively and quantitatively by cyclic thermo-mechanical and stress relaxation tests. Excellent shape memory behavior with fixity ratios above 94% and recovery ratios above 98% is demonstrated. A transesterification catalyst is needed to obtain good vitrimer behavior. Overall, thanks to the previously mentioned properties of those partially biobased thermosets polyesters, industrial applications such as protective coatings, foams and temperature-memory polymer actuators might be considered.

Volatile Organic Compounds (VOCs) having different polarities were absorbed in two viscous waste oils (a transformer oil and a lubricant, whose viscosities are equal to 19 mPa s and 79 mPa s, respectively) in a structured packing (1 m height) operated at counter-current. A synthetic hydrophobic solvent (PDMS 20, a silicone oil) and water were also used as reference solvents. Removal efficiencies of hydrophobic VOCs in silicone and transformer oils up to 80-90% were measured. Nonetheless, owing to a higher viscosity, the removal efficiencies in the lubricant were significantly lower. A deconvolution procedure, based on the Higbie penetration theory, was developed to deduce the local mass transfer coefficients (k(L) and k(G)) from K(L)a degrees values. These local coefficients were compared to the predictions of the models of Billet-Schultes (BS) and Song-Seibert-Rochelle (SSR), allowing to conclude that the SSR model better addresses the influence of the viscosity on K(L)a degrees than the BS model. (C) 2021 Elsevier Ltd. All rights reserved.

The treatment of a gaseous mixture of volatile organic compounds (VOC) using a large-scale installation combining a VOC absorption in silicone oil (PolyDiMethylSiloxane, i.e. PDMS), a biological regeneration of the PDMS in a two-phase partitioning bioreactor (TPPB) and a phase separation including settling and centrifugation was studied in real conditions on an industrial site. The TPPB was operated at a water/PDMS volume ratio of 75/25. The VOC treatment performance was satisfactory during the entire test (158 hours of operation or 10 PDMS regeneration cycles). The analysis of the content of the aqueous phase and PDMS confirmed that VOC are progressively degraded until mineralization. The nitrogen consumption and the characterization of the microorganisms highlighted anoxic functioning of the biomass of the pilot within the first decanter. Moreover, although the performances at the level of absorption and TPPB were very satisfactory, the separation of phases, essential for the recycling of the PDMS, encountered difficulties due to the production of biosurfactants by the microorganisms leading to the formation of a stable emulsion and foaming episodes. As a consequence, the packed column showed slight fouling. However, no significant increase in the pressure drop of the packed bed, as well as no significant impact on VOC absorption efficiency were observed. The phase separation step appears thus as the main problem to solve in order to further develop the treatment of hydrophobic VOC based on TPPB at industrial scale.

The purpose of this work was to study the hydrodynamic behavior of two viscous waste oils (a transformer oil and a lubricant characterized by viscosities of 19 mPa s and 79 mPa s at 25 degrees C, respectively) and a silicone oil (20 mPa s at 25 degrees C) in a laboratory-scale packed column (D-col = 0.12 m). The column was filled with structured packing made of corrugated sheets (Flexipac (R) 500Z HC) and was operated at counter-current. Thus, the gas superficial velocities at the loading point were in the range from 0.40 to 0.65 m s(-1) for liquid loads between 1 and 24 m(3) m(-2) h(-1), and, at the flooding point from 0.56 to 1.07 m s(-1) for liquid loads between 6 and 36 m(3) m(-2) h(-1). Both loading and flooding points were particularly influenced by the solvent viscosity, leading to a narrow loading zone for the most viscous solvent (lubricant). The pressure drop values remained reasonable, lower than 450 Pa m(-1) in the loading zone, even for the lubricant. Billet-Schultes correlations were used for the prediction of the loading and flooding velocities and of the pressure drop. The specific constants of the model were determined. These correlations enable accurate predictions of the loading and flooding points, with an average relative error around 7-8%, and of the pressure drop in the loading zone, with an average relative error of 15%. Simulations were performed with the Billet-Schultes correlations and showed that high liquid holdup and interfacial area would be obtained with these viscous solvents in the selected packing. Scale-up calculations proved that it would be possible to implement the transformer oil at industrial scale in a packed column filled with the studied structured packing. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Undoubtedly, in our current society, the development of more sustainable materials has to be considered in many applications. In this chapter, the interest of new potential biomaterials intended for the fabrication of filtration membranes is discussed. A focus is made on the polyhydroxyalkanoates (PHAs) polymers family. These biobased and biodegradable polyesters have gained attention in the past few years thanks to their versatile properties. Up to date, they have shown promising results for the fabrication of pervaporation and liquid filtration membranes. The membrane performances could be tuned by the use of PHAs having different comonomer contents and by the addition of proper additives. By discussing what has been developed in other application areas, such as biomedical and packaging, some insights are suggested in order to improve the overall PHAs-based membranes properties. Hence, the first part will deal with the membrane technologies and the current polymeric materials used. A second part will highlight the interest of biopolymers. Then, the properties and potential applications of PHAs in the membrane manufacture will be discussed.

Within the current increasing environmental restrictions, biopolymers tend to replace common materials in many applications, from daily life items to process engineering facilities. Synthetic filtration membranes are also of concern. Herein, biopolymer based microfiltration (MF) membranes were produced with a polyhydroxyalkanoate (PHA), the poly(hydoxybutyrate-co-hydroxyvalerate) (PHBHV). The membranes were made by evaporation induced phase separation (EIPS) and the influence of the dope solution composition was studied by adding additives, polyvinylpyrrolidones (PVPs) and polyethylene glycols (PEGs). The nature, molecular weight and concentration of the additives were linked to the obtained microstructures. Both types of additives can increase membrane porosity by acting as pore former agent. However, interesting opposite effects were obtained in case of PEGs from 300 to 4000 g mol(-1) where the additives were observed to act as plasticizers. The membranes performances were evaluated with pure water permeability and E. coli bacteria rejection and correlated to the microstructure analyses. The performances were greatly improved by selecting the proper additive. This study leads to promising results for the consideration of PHA as new potential biomaterial intended for membrane fabrication.

Within the purpose of developing more sustainable membrane systems, it is herein proposed to implement a biobased and biodegradable material, the poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV), to replace conventional polymers in a commonly used membrane fabrication process. The PHBHV based membranes were made by non-solvent induced phase separation (NIPS) using N-methyl-2-pyrrolidone (NMP) as solvent. The process parameters and dope solution composition were developed in order to give structures suitable for performances characterization. In that sense, the microstructures were characterized in case of non-supported and supported membranes. The addition of hydrophilic additives, ethylene glycol (EG) and polyethylene glycol 300 g mol(-1) (PEG300), was linked to the morphology changes. Porous asymmetric membranes were obtained in case of the non-supported membranes or supported membranes with a low amount of additive (1 wt%). Otherwise, symmetric porous membranes, made of interconnected crystal lamellas, were observed. The particularly high crystallinity of this biomaterial involved some different microstructures compared to classic polymers. Both types of structures demonstrated decent rejections of a clay dispersion. Due to the increased pore size, the permeabilities were greatly improved with the additives and values up to 480 L m(-2) h(-1) .bar(-1) were achieved.

The purpose of this study was to test different kinds of industrial waste oils to be implemented as Non-Aqueous-Phase for Volatile Organic Compounds absorption and degradation in a process coupling a packed column and a Two-Phase Partitioning Bioreactor. Engine, hydraulic, transformer and vegetable oils were tested. The VOC targeted were: n-heptane, ethyl acetate, isopropanol, methylisobutylketone, toluene, m-xylene and 1,3,5-trimethylbenzene. Several parameters were determined: volatility, viscosity, VOC partition coefficients and toxicity. Results allowed to conclude that hydraulic, transformer and vegetable oils are technically appropriate for the process. According to availability and cost data of waste oils, hydraulic oil was selected.

Sodium hypochlorite is widely used to clean/sanitize PES/PVP membranes. However, this strong oxidant is responsible for accelerated polymer ageing, thus impairing PES/PVP membrane lifespan. This work aimed at getting a better understanding of the role of PVP in the degradation of PES/PVP membranes. As the precise chemical composition of commercial membranes is most often unknown, PES/PVP membranes with various PVP to PES ratios (from 0 to 44 wt%) were synthesized and aged dynamically by filtering sodium hypochlorite solutions. PVP oxidization and partial disappearance from the membrane matrix was observed whatever the membrane composition. Moreover, PES-chain scissions were put in evidence even for pure PES membranes, thus highlighting that PES degradation was not systematically related to the presence of PVP. Conversely, PES hydroxylation was observed only for membranes containing PVP, the hydroxylation rate being dependent on the PVP content. Interestingly, the occurrence of PES-chain scissions impacted the membrane filtration performance while no correlation was found between the PES hydroxylation rate and the filtration performance.

ABSTRACTNew biobased polyurethanes were synthesized from cyclocarbonated broccoli seed oil and different di‐ or triamines. The isocyanate‐free route to synthesize these polyurethanes was divided into three steps: the broccoli seed oil was first epoxydized, then carbonated with CO2 at a pressure of 50 bar to convert oxiranes into cyclic carbonates, and finally polyurethanes were prepared through the reaction of the cyclocarbonated oil with three different di‐ or triamines, that is, butylene diamine, m‐xylene diamine, and bis(hexamethylene triamine). The chemical reactions were monitored by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and electrospray ionisation mass spectrometry and mechanical properties of thus‐prepared polyurethanes were determined by dynamic mechanical analysis and tensile characterization. An UV‐responsive material was finally prepared from butylene diamine based polyurethane integrating phosphorescent molybdenum nanoclusters. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45339.

The present article reports a study of oxidative degradation under eBeam irradiation of neat PHBV, neat PLA and PHBV/PLA blend (50/50 w/w) with and without Cloisite 30B (C30B) (3 wt%) at absorbed doses of 1 and 10 kGy. The changes in the chemical structure, the molecular weight, the thermal, mechanical and barrier properties as well as the morphology were evaluated. The data showed that eBeam irradiation of PHBV/PLA blend leads to oxidation reactions involving ester groups in both neat PLA and neat PHBV resulting in the formation of hydroperoxides groups. The presence of C30B in the polymer blend has no influence on the nature of the degradation process. However, the good dispersion of C30B nanoparticles provides more stability to the molar mass and the thermal, mechanical and barrier properties of PHBV/PIA blend. At absorbed dose of 10 kGy, the irradiated samples are completely safe. Furthermore, ecotoxicity testing of both non irradiated and irradiated samples clearly showed no toxicity. (C) 2016 Elsevier Ltd. All rights reserved.

Polyhydroxyalkanoates (PHA) are bacterial polyesters usually produced from costly sugars or volatile fatty acids (VFAs). In this work, two processing waters rich in vegetable proteins and reducing sugars, i.e., a mixture of saccharose and stachyose in Leguminous Processing Water (LPW) and a mixture of glucose and fructose in Fruit Processing Water (FPW), were tested as growth medium for PHA production in a two-stage fermentation with a unique marine bacterial species: Halomonas i4786. In preliminary shake flask experiments, it was shown that the two media can effectively support the bacterial growth and the accumulation of PHA (evaluated using Nile Red staining). In batch cultivation mode in a 5-L fermentor, PHA productivities of 1.6gL−1 and 1.8gL−1 were further achieved within 72h, in LPW and FPW respectively. Polymer characterization by Differential Scanning Calorimetry and Steric Exclusion Chromatography indicated that the two substrates led to the biosynthesis of polymers with different chain length, distribution and crystallinity. To summarize, these results show that by-products derived from local agri-food industry can be used as a user-adapted and cost-effective source to produce bio-sourced and biodegradable plastic materials.

The expansion of polyhydroxyalkanoates (PHAs) into the biodegradable polymers market is mainly prevented by their production process which is still complicated with a low efficiency, resulting in relatively expensive products. In this study, we developed a method that used the lipophilic fluorescent probe Nile Red (1 mg l−1 solution in DMSO) directly into the culture broth to stain the PHA inclusions inside bacterial cells followed by detection of the emitted fluorescence by both microscopic and spectrometric techniques. Epifluorescence microscopy provides a rapid tool to distinguish producing from non-producing bacterial species and the relative fluorescence intensity (FI) determined at the maximum of emission spectra in the wavelength region of 560–710 nm (λex: 543 nm), allows a fast assessment of the cultural conditions that may enhance PHA production yield. During two-step cultivation in 500-ml flasks with glucose as the sole carbon source, the method aimed to select bacterial strains efficient for PHA synthesis among a marine collection. Subsequently, the NR assay was used to determine the C0/N0 ratio of the producing media that may improve the polymer yield as well as to follow the time course of fermentation. Characterization by GC–MS and DSC confirmed the production of the P(3-HB) homopolymer.