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Дисертації з теми "Polymères biosourcés – Conception – Évaluation"
Ruellan, Alexandre. "Conception raisonnée à l’aide de la formulation et du procédé d’un film souple biosourcé et biodégradable pour l’emballage alimentaire." Electronic Thesis or Diss., Paris, AgroParisTech, 2015. http://www.theses.fr/2015AGPT0032.
Повний текст джерелаThe use of renewable resources and the production of biodegradable materials are appropriate solutions to reduce the environmental impact of the sector of plastics. There is thus a demand for eco-friendly products on the market provided they obtain performance equal or superior to synthetic materials currently used. One possibility, widely used in the food sector, to achieve efficient packaging film is the creation of multilayer structures by combining advantageous properties of different plastics. In this case, recycling of materials is difficult and the biodegradability of the packaging becomes relevant. This study proposes designing biobased and biodegradable films for food packaging from polylactide and co- products of the oil mill industry as additives, in particular the deodorization condensates. Among these lasts, the partial solubility of their molecules and the synergetic effect of the liquid and solid fat components at room temperature, depending on their alkyl chain length and unsaturation ratio, have both been observed to be responsible for the ductility increase, while the higher than room temperature glass transition of PLA and its interesting rigidity were retained. Addition of PHBV to the formulated PLA with oil by-products has also been studied, mainly leading to a significant improvement in the thermomechanical resistance of the material. Scaled-up trials comprising the production of formulated pellets, cast extruded films and their printing using industrial devices were performed. Finally, with the help of the “Laboratoire National de Métrologie et d’Essais” (LNE), the compliance with requirements of Food Contact Material regulation of a formulated film of PLA, as well as its biodegradability according to the EN 13432 standard, have both been proved
Vo, Van Son. "Élaboration, caractérisation et simulation de nanocomposites argile-polymère : des nouveaux matériaux pour l'éco-conception." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1162/document.
Повний текст джерелаClay nanoparticles (CNP) are abundantly available low-cost natural resources with numerous positive attributes such as large surface area, impermeability to gas, superior mechanical and thermal properties so that they have attracted over the last three decades significant attention, notably for the reinforcement of polymer-based materials. However, CNP suffer from incompatibility, hence weak interfacial interactions and poor dispersion with/in most of organic polymeric materials because of their intrinsic hydrophilicity and strong interlayer interactions. This limitation is one of the major reasons why polymer nanocomposites have to date remained mainly in laboratories. Thus, one of the key challenges in developing clay-based polymer nanocomposites (PCNs) with advanced thermo-mechanical, gas barrier...properties relies on the control at the molecular level of the interface properties of clay nanoplatelets-filled polymer resins. Taking into account the criteria for sustainable development, civil engineering and green economy, we have developed, in the first part of this thesis, reactive and pre-exfoliated clay nanofillers that may be further incorporated in a diverse set of biopolymer matrices and giving rise to strong energy interactions with the said matrices for improved mechanical behavior. To ensure a closer fit of these specifications we have implemented green approaches for the preparation of these generic nanofillers, namely photopolymerisation was used as a low energy consumption and fast method for the surface functionalization of native clays, solvent-free protocols were applied to prepare polymer nanocomposites, while biopolymers (starch, cellulose) or bio-based precursors (epoxidized vegetal oils) served as dispersion media. By controlling the preparation conditions, reactive clay nanofillers with adjustable interlayer spacing and chemical surface reactivity were prepared. Of particular interest is that the layered-like structure of the clay nano ller is preserved while the d-interlayer spacing can be increased though increasing the photopolymerization time, i.e. amount of polymer within the clay nanosheets. Our major results from the the first part can be summarized as follows: Morphology and reactivity of clay nanofillers are easily controlled though adjusting the photopolymerization time and selecting adequate vinyl monomer. - The newly preparation methods allow preparation of samples beyond the gram-scale. - Reactive and surface chemistry of pre-exfoliated clay nanofillers can be tuned to provide compatibility with both conventional preformed biopolymers and bio-based epoxy resins. - The mechanical properties of the resulting polymer nanocomposites are improved as compared to the neat polymeric matrices owing to the strong interface interaction between fillers and dispersion matrices
Kachbi, Souad. "Vectorisation d’antitumoraux phosphorés greffés sur différentes plateformes polymères : conception, synthèse et évaluation biologique." Paris 13, 2013. http://scbd-sto.univ-paris13.fr/secure/edgalilee_th_2013_kachbi.pdf.
Повний текст джерелаNowadays, one of the major advances in drug delivery systems is their conjugation to polymeric platforms. This work is focused on the vectorization of the phosphorus antitumor agent by their grafting into natural or synthetic polymeric platforms. The design, synthesis and biological evaluation of these conjugates were studied. We have then vectorized the bisphosphonates by using inert polymeric macromolecular carrier either natural: dextran or synthetic HPMA copolymers in order to change their natural target which is bone. For the biodegradable natural conjugate, we have synthesized two CMD-BP systems, which are characterized and evaluated biologically in vitro and in vivo. Moreover, for the synthetic conjugates, we developed different families of bioactive methacrylic comonomers bearing bisphosphonates which have different chain length and linkers with various chemical nature between the methacrylate group and bisphosphonate. Afterwards, the original monomers were copolymerized with HPMA using the RAFT polymerization; this allowed to obtain copolymers bearing BP with a narrow size distribution and controlled molecular weight
Msolli, Ines. "Nanosystèmes polymères pour la libération contrôlé de la Warfarine : conception et évaluation biologique." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCD033/document.
Повний текст джерелаIn this work we synthesized derivatives of poly((R,S)-3,3-dimethylmalic acid) (PDMMLA).PDMMLA copolymers are mainly composed of two monomers: a hydrophobic monomercontaining a hydroxyl group and a hydrophilic monomer containing an acid group. Due to theproportion of each monomer in the final copolymer, the hydrophilic / hydrophobic balance ismodulated. Thus, six copolymers were obtained: three random copolymers PDMMLAHn-co-Hex100-n and three block copolymers: PDMMLAHn-b-Hex100-n.These copolymers are at the origin of nanoparticles without and with an active principle.Warfarin, which has been successfully encapsulated with both PDMMLAHn-co-Hex100-nand block, copolymer nanoparticles: PDMMLAHn-b-Hex100-n. The formed nanoparticlesshowed fairly high encapsulation efficiency for both types of copolymers.The PDMMLA nanoparticles are characterized in order to determine their shape, size andsurface charge. Thus nanoparticles of spherical shape, having less than 100 nm size andhaving a surface charge of less than -30 mV have been obtained. The PDMMLAH30-co-Hex70nanoparticles were chosen to study the controlled release of warfarin under physiologicaltemperature and pH conditions. Obtained results show a slow and progressive release ofwarfarin. Such nanoparticulate systems based on amphiphilic derivatives of PDMMLA wouldthus offer tools of interest for the encapsulation and controlled release of many hydrophobicactive principles such as the coumarin derivative thrombin inhibitor (DCBC) whoseantithrombin activity in purified system is higher than that of argatroban
Creusat, Gaelle. "Conception et évaluation de vecteurs synthétiques pour la transfection de siRNA à des fins thérapeutiques." Université Louis Pasteur (Strasbourg) (1971-2008), 2008. http://www.theses.fr/2008STR13191.
Повний текст джерелаRNA interference is a natural cellular process allowing post-transcriptional gene silencing. This specific mecanism, triggered by double-stranded RNA, is a revolutionary tool to study gene function and has potential therapeutic applications. By now, siRNA delivery is the major obstacle to widespread application of RNAi. PEI is one of the most efficient vectors for gene transfer in vivo. However, this cationic polymer has a low efficiency in delivering siRNA. In this work, we have demonstrated that PEI is poorly efficient, because polyplexes are instable, due to low electrostatic cooperativity between siRNA and the cationic vector. Therefore, it is necessary to improve polyplexes stability for efficient delivery. Our first approach consisted in polyplexes cross-linking with disulfure bridges. Then in a second approach, we have modified PEI with hydrophobic amino-acids, to favor vector-vector association
Hanani, Zouhair. "Conception de composite flexible céramique sans plomb/biopolymère pour des applications de stockage et de récupération d'énergie." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0288.
Повний текст джерелаThe existing energy storage and harvesting devices suffer from the moderate performances, low flexibility and the use of toxic compounds. This is how ceramic/polymer nanocomposite approach is highly promising for high-efficiency energy storage and harvesting applications, due to the high dielectric constant of the ceramic and the high breakdown strength, the flexibility and the ease of processing of the polymer. This thesis focuses on designing ceramic (BCZT)/polymer (PLA) nanocomposites for these applications. First, controlled syntheses of BCZT ceramics with different particle sizes, size distributions and shapes were performed and discussed. The effects of grain size and grain shape of BCZT ceramics on the dielectric properties were studied. It was found that the BCZT ceramic with near-spherical particles elaborated by low-temperature hydrothermal processing at 160 °C revealed enhanced dielectric and ferroelectric properties compared to the BCZT ceramics synthesized by other methods. Second, BCZT near-spherical particles BCZT nanorods and HZTO nanowires were embedded in the biodegradable PLA polymer matrix. The effects of the ceramic shape, arrangement, dielectric constant and aspect ratio on the dielectric constant of the nanocomposite were explored using the effective dielectric constant of the nanocomposite models. It was found that for improving the dielectric properties of the composite, it is important to control the ceramic fillers geometry rather the use of high-k ceramics. Afterwards, the energy storage properties of PLA-based nanocomposites were evaluated by D−E hysteresis loops, and high-energy storage performances were obtained in the nanocomposites based on rod-like fillers. The energy harvesting aspect was investigated by designing a bio-flexible piezoelectric nanogenerator (BF-PNG) based on BCZT/PLA nanocomposite film to convert the ambient mechanical energy to electrical energy. This BF-PNG could generate open-circuit voltage and short-circuit current of 14.4 V and 0.55 µA, respectively, and large power density of 7.54 mW/cm3 at a low resistive load of 3.5 MΩ, under gentle finger tapping. The feasibility of the BF-PNG was tested by driving commercial electronics (charging capacitors and lighting an LED). Accordingly, this work demonstrates that BCZT lead-free ceramic in combination with PLA biopolymer can lead to flexible nanocomposite with enhanced energy storage and energy harvesting performances for application in self-powered devices
Mogrovejo, Valdivia Alejandra. "Conception et évaluation d'un pansement à libération de deux principes actifs pour le traitement des plaies chroniques." Thesis, Lille 2, 2018. http://www.theses.fr/2018LIL2S046.
Повний текст джерелаChronic wounds present a risk of infection, delaying the healing process and leading to severe pain. Chronic wounds represent a public health problem that generates high costs. Silver dressings are widely used to treat wounds already infected or with a risk of infection. Nevertheless, the toxic effect of silver toward fibroblasts and keratinocytes generates a perception lack of efficacy and cost effectiveness, and question their effectiveness as well as its safety. The goal of this work was to design a wound dressing releasing two active ingredients: a silver salt to treat the infection and ibuprofen to relieve the pain. The dressing was coated by a layer-by-layer (L-b-L) system to slow down silver diffusion into the wound and at the same time provide a moist environment to the wound. First, a nonwoven polyester textile was functionalized by chitosan or by β-cyclodextrin polymer, both crosslinked with citric acid under curing conditions to form a thermofixed negatively charged layer at the surface textile to then loaded silver onto the textile. Next, a L-b-L system was built on the support by alternating self-deposition of CHT as cationic polyelectrolyte and cyclodextrin polymer as anionic polyelectrolyte. A curing process was applied to stabilize the L-b-L system. L-b-L system showed a linear evolution of the weight gain in relation to number of layers formed. Loaded silver and ibuprofen reached up to 240 μg/cm2 and 200 μg/cm2 respectively. Silver was released up to 3 μg/cm2 after 3 days in PBS under static conditions, and ibuprofen was released up to 6 hours under the same parameters. Biological studies proved the dressing cytocompatibility using human lung normal cell lines (L132). In vitro microbiological evaluation showed greater antibacterial activity of the dressing against S. aureus and E. coli. Finally, a preliminary in vivo study was performed in C3H/HE mice with a wound infected by E. coli. The dressings tested were applied to the wounds and were maintained for 3 days. Only the free silver-dressing (negative control) showed a colonization by E. coli
Grassin, Adrien. "Conception, synthèse et caractérisation de vecteurs pour la nanomédecine : applications en thérapie anticancéreuse." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GRENV004/document.
Повний текст джерелаCancer research is now taking advantage of nanomedicine that is to say the use of nanoparticles to increase treatment efficiency and reduce toxicity. In this context, this work has been devoted to the design and synthesis of nano objects for applications in cancer therapy. These systems are based on a cyclodecapeptidic molecular scaffold presenting several RGD peptidic ligands targeting the αvβ3 integrin, a transmembrane receptor playing a key role in angiogenesis. We first synthesized several compounds by modifying the structure of the peptidic scaffold in order to alter the presentation of the RGD ligands during their interaction with the αvβ3 integrin. Biological in vitro evaluation of the different synthesized compounds followed by dynamics simulation allowed us to identify an optimal presentation of the RGD ligands. We then developed a new synthesis combining two orthogonal copper-catalyzed reactions yielding those peptidic vectors with lower reaction times and better yields compared to the classic synthesis. We finally grafted the RGD clusters on lipidic, then polymeric nanoparticles to add targeting moieties. Both projects were realized through collaborations, respectively with Prof. Patrick Couvreur’s lab (squalene nanoparticles) and Dr. Marie-Thérèse Charreyre’s lab (NAM/NAS copolymers). Those systems were then evaluated in vitro for applications in therapy and imaging
Muralidhara, Anitha. "Physico-chemical safety issues pertaining to biosourced furanics valorization with a focus on humins as biomass resource." Thesis, Compiègne, 2019. http://www.theses.fr/2019COMP2508.
Повний текст джерелаThe present research work was integrated as part of the EU-funded project named HUGS (HUmins as Green and Sustainable precursors for eco-friendly building blocks and materials), involving 5 main partners (Institut national de l'environnement industriel et des risques - France, Avantium - the Netherlands, Institut de Chimie de Nice - France, Universidad De Cordoba- Spain and Leibniz - Institut Fur Katalyse Ev An Der Universitat Rostock- Germany). The project is essentially supported through five European Industrial Doctorate fellowships put in place when the HUGS-MSCA-ITN-2015 program was launched in 2016. The primary objective of the HUGS project was to explore several valorization pathways of so-called “humins” in order to add value and create better business cases. Humins (and similarly lignins) are the side products that may become low-cost feedstock resulting from a number of future biorefineries and sugar conversion processes. Humins are complex residues resulting from the Acid-Catalyzed Dehydration and condensation of sugars, having furan-rings in their polymeric structures. The work presented in this specific part of the HUGS project is essentially focusing on safety-related topics of all components and subsequent applications related to sugar dehydration technology. Priority actions were devoted to a first insight on the characterization of physicochemical safety profiles of the side-product humins and main (parent) furanic products. Some members of this large family of compounds (e.g. RMF and FDCA) have high volume potential which results in opening new doors towards the development of furanbased building blocks and a bio-based economy. Humins are residues or side products which can be burnt for energy. However, its safe and sustainable use in high-value applications could also become a key milestone in the so-called circular economy. In practice, the work has been developed in two main locations: primarily at the INERIS lab, located in Verneuil-en-Halatte and at Avantium, located in Amsterdam. Nearly all experimental research after the production of the components at Avantium was performed at INERIS. This involved the evaluation of physicochemical hazards of both humins (crude industrial humins and humin foams obtained by thermal curing) and a series of furanic compounds. Avantium is involved in the commercialization of humins, furanics and furanic polymers/materials as novel chemicals and materials. The work has encompassed: An extensive bibliographical review of humins, furanics, and their related products (polymers, composites) resulted in the following main conclusions o A lack of physicochemical safety-oriented studies for many furanic compounds and for humins was observed as these products are still in the early stage of development and only a few may be commercialized in the next 5 years.o Despite the limited availability of safety-related data, more studies on toxicity aspects have been conducted for a selected number of furanics than physicochemical safety-related aspects. o A few furanic family members that have been evaluated as biofuel components were found to have given better emphasis on addressing some physicochemical safety attributes. o Every modification of the process for acid-catalyzed sugar dehydration (such as solvent, temperature, residence time and sugar concentration) will result in different humins, which would certainly demand further characterization and safety profiling of the resulting humins. • Analytical development integrating the first examination of flash point distribution versus the Net Heating Values, and analysis of total heats of combustion of furanic compounds. • Design and development of experimental plan addressing the safety-related key parameters such as thermal stability, self-heating risks, fire-risk-assessment and flammability limits depending on the need for specific tests and availability of the test samples