Abdominal hernia repair is a common surgical procedure, involving in most cases the use of textile meshes providing a mechanical barrier to consolidate the damaged surrounding tissues and prevent the resurgence of the hernia. However, in more than half cases postoperative complications such as adhesions and infections occur at the surface of the mesh, leading to chronic pain for the patient and requiring the removal of the implant. One of the most promising strategies to reduce the risk of postoperative adhesions and infections is to add a physical barrier between the mesh and the abdominal walls. In this study, we propose a strategy to develop functional hernia meshes possessing anticoagulant and antibacterial activities depending on the side of the implant. Two bioactive polymers were synthetized: a polysulfonate (poly(2-acrylamido-2-methylpropane sulfonic acid), PAMPS) one for anticoagulant activity and a polymer bearing ternary amines (poly((2-tert-butylamino) ethyl methacrylate), PTBAEMA) for antibacterial activity. These polymers were used to produce core-sheath nanofibers thanks to coaxial electrospinning with poly(ɛ-caprolactone) (PCL) as core and the bioactive polymer as sheath. The electrospinning parameters were optimized in order to obtain defect-free nanofibrous coatings onto the mesh with improved stability in water. The core-sheath structure was investigated as well as the presence of the functional groups at the surface. The in vitro cytocompatibility, anticoagulant activity and antibacterial activity were evaluated and highlighted the high potential of these coatings for the simultaneous prevention of postoperative adhesions and infections.

At the vicinity of metallurgical and steel activities, notable contamination of Potentially Toxic Elements (PTE) is measured in discrete environmental compartments (soils, biosphere, atmosphere). The main question addressed in this study pertains to the influence of industrial dust fallout on PTE concentrations in soils. The study was conducted near the seaport of Dunkerque, belonging to one of the most industrialised and dust-emitting sites of France. A composite sample of dust fallout was collected over a 4-month-period in urban areas downwind of nearby industries. SEM-EDS and ICP-AES/MS analyses were conducted on this sample to identify metallurgical particles and highlight the main tracer elements of industrial activities. Then, a comprehensive characterization of soils was conducted to map the spatial distribution of metallic pollution levels in the study area. Nearby soil parameters analysis (grain-size distribution, pH, CEC, SOM, calcium carbonates and water contents), the soil chemical composition was identified using XRF and ICP-AES/MS analyses. We quantified the proportion of particles of industrial origin in the composite dust sample at 88

Environmental sustainability and multifunctionality are now key drivers for smart coatings design and applications. In a circular economy that promotes durable materials, the challenge is to develop multi-functional onepot coating materials. The eco-efficient self-stratification process allows the spontaneous formation of complex polymer multilayers in only one step of formulation, application, and curing. This leads to the simultaneous production of both an undercoat and a finishing coating with all the properties needed to protect a material. In addition, film formation in a single application step drastically reduces adhesion failures and contamination between layers. The original idea in this study was to conceive a self-stratifying and self-healing coating formulation using a bio-based epoxy resin and a PDMS-based vitrimer, by taking advantage of the self-healing properties of the vitrimers. This newly discovered class of polymers possess dynamic covalent bonds. This epoxy resin - dynamic PDMS blend was successfully applied on polycarbonate substrates by spraying and exhibited a type I stratification associated with room temperature self-healing properties. Furthermore, the coating showed great adhesion to the substrate, on the contrary to the dynamic-PDMS when applied directly onto polycarbonate. The stratification was observed with SEM-EDS imaging. The self-healing property was proven by optical microscopy imaging of scratches under different thermal treatments. FT-IR and wet contact angle were used to further characterize the synthetized dyn-PDMS.

Environmental sustainability and multifunctionality are now key drivers for smart coatings design and applications. In a circular economy that promotes durable materials, the challenge is to develop multi-functional one-pot coating materials. The eco-efficient self-stratification process allows the spontaneous formation of complex polymer multilayers in only one step of formulation, application, and curing. This leads to the simultaneous production of both an undercoat and a finishing coating with all the properties needed to protect a material. In addition, film formation in a single application step drastically reduces adhesion failures and contamination between layers. The original idea in this study was to conceive a self-stratifying and self-healing coating formulation using a bio-based epoxy and a PDMS-based vitrimer, by taking advantage of the self-healing properties of the vitrimers, this newly discovered class of polymer with dynamic bonds. This epoxy – dynamic PDMS blend was successfully applied on polycarbonate substrates by spraying and exhibited a type I stratification associated with room temperature self-healing properties. Furthermore, the coating showed great adhesion to the substrate, on the contrary to the dynamic-PDMS when applied directly onto polycarbonate. The stratification was observed with SEM-EDS imaging. The self-healing property was proven by optical microscopy imaging of scratches under different thermal treatments. FT-IR and wet contact angle were used to further characterize the synthesized dyn-PDMS.

Artificial turf structures are increasingly used in closed areas and have to comply with the European fire standard for building products (EN ISO 13501-1). The main test to evaluate the fire performance of flooring products is the EN ISO 9239-1 radiant panel test. The test principle is to determine the critical heat flux of floorings exposed to a forced ignition and a specific heat flux profile. As large amounts of material are needed to perform the test, the development of a radiant panel test at reduced scale was considered. The experimental design methodology was implemented to mimic the heat flux profile. The fire performance of artificial turf structures was evaluated at both scales and the results were compared. The burnt lengths of the specimens and thus the critical heat flux are similar for both scales. Thus, the downscaled device could advantageously be used for high throughput development of artificial turf structures.

Recovery of plastic waste is becoming crucial since the amount of such waste increases continuously. The objective of this study is to investigate the potential of the pyrolysis technique for the recovery of plastic waste. In that frame, the influence of temperature (550 degrees C or 600 degrees C) on the pyrolysis of pure polypropylene (PP), polyethylene (PE), polystyrene (PS) and polyethylene terephthalate (PET) was first studied. It is shown that whatever the type of polymer, aromatic compounds are mainly formed and could reach 55wt.-% of the oil fraction for PP and 31wt.-% for PE at 550 degrees C. In a second step, a PP/PE mixture and a model mixture representative of the packaging plastic waste stream were pyrolyzed to investigate the influence of a combination of polymers on the proportions and composition of the different fractions. The pyrolysis of the polymer mixtures shows that, even if the aromatic compounds formed are similar to those obtained for the virgin polymers, the proportion of aromatic compounds is much more important than when the polymers are pyrolyzed alone. Indeed, mixing PE with PP at a 50/50 ratio does not affect the amount of liquid, gas and solid fractions but leads to the formation of a higher quantity of xylene (39 wt-%) at 550 degrees C. The combination of the plastics in the model mixture has also led to a decrease of the amount of waxy compounds. Furthermore, it was shown that a higher amount of aromatics than expected was formed. As a conclusion, this study demonstrates that pyrolysis is an effective technique to recover plastic waste as aromatic compounds for the petroleum industry. In the specific conditions used in this study (proposed model mixture and pyrolysis conditions), it will favor the idea that sorting is not needed to recover plastic waste through pyrolysis since aromatics formation is favored when the stream is composed of a mixture of polymers. (C) 2021 Published by Elsevier Ltd.

Self-stratification is an innovative one-step process used to design multi-functional coatings gathering simultaneously in a one-pot formulation the primer, the intermediate layer and the top coat properties. Many selfstratifying coatings contain oil-based epoxy resins but the literature is scarce in the development of "greener" solutions. In this work, silicone resins and bio-based epoxy resins were dissolved in various solvent blends, applied on a composite substrate and cured under different conditions to obtain stratified coatings. To reach a perfect stratification, the influence of various parameters including (i) the surface tension and the polarity of the resins, (ii) the solvents volatility, (iii) the curing temperature and (iv) the reactivity of the epoxy/amine reaction was studied by a systematic approach. In accordance with the literature, it was demonstrated that a large difference in surface energy and polarity favors resins separation. The volatility of the solvent blend was also shown to be a key factor in the stratification process. However, the predominant parameter, rarely taken into account, is the curing temperature, which impacts the cross-linking reaction of the epoxy resin. The increase in molecular weight (MW) of epoxy resins due to the cross-linking reaction favors the incompatibility between resins by increasing the difference in MW between epoxy and silicone resins. Thus, optimization of process conditions allowed the design of perfectly stratified bio-based epoxy/silicone coatings. The mechanism of film stratification was also elucidated thanks to in-situ analyses.

Abdominal hernia reparation constitutes the second surgical operation in the world with more than 20 million cases per year. However, in more than 50 % of all intra-abdominal operations, postoperative adhesions occur and result in important pain for patients. These adhesions take place after excessive deposition of fibrin between peritoneum and organs within the 7 days after the operation which occurs during the coagulation cascade. For this reason, therapeutic solutions are required to both prevent adhesion and limit the need for a second surgical step. Numerous techniques were described in the past few decades to design biomedical textile implants and, among them, electrospinning shows great interest due to the porous and nanometer diameter range structure of the obtained fibers. In parallel, cold plasma treatment can be used to activate and graft their surface with functional molecules, exhibiting for example antibacterial or anticoagulant properties. This work aims at functionalizing, biodegradable polycaprolactone (PCL) electrospun nanofibers covering polypropylene meshes (PPM) with 2-acrylamido-2-methylpropane sulfonic acid (AMPS) through cold plasma induced graft copolymerization. AMPS was chosen as it contains heparin-like segments, leading potentially to similar anticoagulant effect. First, electrospinning of PCL was optimized by varying process, solution and environmental parameters and allowed to select a solution of 12 % of PCL in formic/acetic acid mixture. The graft-copolymerization of AMPS was then optimized in terms of power and time of plasma treatment, as well as solution concentration, using experimental design, in order to obtain nanofibers rich in SO3H groups at their surface. At each step of the process, the material was thoroughly characterized proving the presence of AMPS onto the surface of the nanofibers. The cytocompatibility and anticoagulant properties, evaluated after sterilization, are promising for an anti-adhesive application of these nanofibrous mats with no release of cytotoxic compound.

Nowadays, before setting up an industrial process, special attention has to be paid to its environmental footprint. This new way of thinking allows evaluating the hotspots so as to propose solutions to conceive more eco-friendly processes. Thus, the coating industry is increasingly preoccupied by the environmental impacts of newly designed paints. That is why innovation tries to take into consideration both the formulation composition and the application and drying methods. Following a Life Cycle Assessment (LCA) approach, the present study aims to compare the environmental impacts of self-stratifying coatings (with three process steps), either oil-based or bio-based, to those of an oil-based multilayered coating (with six process steps). The concept of the self-stratifying coating is to bring the primer, the intermediate and the top coat properties together in a one-pot formulation to produce a multi-functional coating through a less laborious process. The total environmental impact of each process can be characterized by four main categories of impacts: Climate Change Human Health (CCHH), Human Toxicity (HT), Climate Change Ecosystem (CCE) and Fossil Depletion (FD), which together represent approximately 86% of the global impact for each system. The results obtained show that the self-stratifying oil-based coating process is more energy efficient compared to the currently used multilayered oil-based coating process, with a 15% decrease of CCHH, HT and CCE indicators and a 14% decrease of FD indicator, corresponding to a 13.6% decrease of the total environmental impact. However, as this decrease was lower than expected, particular attention was then paid to the chemicals used (resins, solvents) and to the process conditions. The substitution of the oil-based epoxy resin by a bio-based one and the use of less harmful solvents allow reducing the total environmental impact by 32.4% compared to the multilayered oil-based system (with 30% decrease of CCHH indicator, 50% of HT indicator, 31% of CCE indicator and 34% of FD indicator). In a global way, electricity consumption control and the nature of chemicals used were reported to contribute in a significant way to the improvement of the process environmental impact. (c) 2019 Elsevier Ltd. All rights reserved.

Lowering fire hazard raised by combustible materials such as plastics may be achieved by the use of suitable flame retardant treatments, like fire protective coatings. However, exposure to long-term environmental conditions can cause loss of their functional properties, thus reducing their effectiveness over time. This is why two or three different layers with specific properties (e.g. adhesive, fire retardant and hydrophobic) are generally needed to provide durable fire retardancy. Effective and economical self-layering coatings can be developed to reduce the number of layers without compromising the advantages of the actual system. In this work, the efficiency of applying a silicone based coating to fire retard polycarbonate and the modification of the behaviors of the system, using a mixture of epoxy/silicone resins, a curing agent and either iron oxide or calcium carbonate as fire retardant filler is investigated. Self-stratification and fillers dispersion were evidenced by microscopic analyses coupled with chemical detection, the flame retardant properties using Limiting Oxygen Index (LOI), UL-94, Mass Loss Calorimetry (MLC), Thermogravimetric analyses (TGA) and a tubular furnace, and aging resistance by accelerated thermal, humidity and UV exposure. It appears that the selected fillers have no negative effect on the layering process when introduced from 2.5 to 10 vol.%: perfect stratification is obtained, with the silicone layer being the top layer. The best improvements in terms of fire retardant properties, adhesion and fillers dispersion were obtained by incorporating 2.5 vol.%: V0 rating at UL-94 and 33 and 35 vol.% at LOI with Fe2O3 and CaCO3 respectively were measured when a 200 inn wet thick coating was applied. The coating containing iron oxide was unaffected by weathering conditions. Finally, the application of those coatings on polycarbonate allows the formation of a protective barrier which limits substrate/flame mass transfers. It therefore results in (i) a delay of the time to ignition, (ii) the inhibition of the flame spread and of dripping when submitted to a flame, and (iii) a reduction of the combustibility of polycarbonate. A modification of the structure of the silica network formed by the particles which enhances the barrier effect of the silicone-based layer would be the most probable assumption to explain these excellent results.