Recherche de nouveaux polymères pour une application dans des matériaux dentaires stables et durables (ynthèse, polymérisation et propriétés adhésives)

Ce mémoire est consacré à la synthèse, la photopolymérisation et les propriétés adhésives de nouveaux monomères acides pour une application dans les adhésifs dentaires et les colles auto-adhésives. Pour une application dans les adhésifs dentaires : Afin d améliorer la stabilité, durabilité et les propriétés adhésives des adhésifs auto-mordançants (SAM1 et SAM2), de nouveaux monomères acides phosphoniques, difluorométhylphosphoniques et bisphosphoniques stables en milieu aqueux ont été synthétisés. L influence de nombreux paramètres (longueur du groupement espaceur, nature de la fonction acide et de la fonction polymérisable etc ) sur la stabilité, l adhésion à la dentine et à l émail a été mise en évidence par des tests d adhérence et par la photopolymérisation en photo-DSC. L interaction entre les fonctions acides et l hydroxyapatite a été étudiée par la RMN solide, l XPS et l ICP-AES. Certains de ces adhésifs se sont avérés plus performant que des formulations commerciales. Pour une application dans les colles auto-adhésives : De nouveaux méthacrylates porteurs de fonctions acides phosphoniques ont été synthétisés. Ces monomères ont ensuite été introduits dans un mélange bisGMA/TEGDMA (1/1). La copolymérisation de ces mélanges par photo-DSC montre que l incorporation de monomères acides porteur de la fonction acide phosphonique provoque une diminution de la vitesse de polymérisation. Une nouvelle colle auto-adhésive duale a été mise au point.This work deals with the synthesis, the photopolymerization and the adhesive properties of new acidic monomers for dental applications. In self-etch adhesive field: In order to improve self-etch adhesives (SEA) stability, durability and adhesive properties, novel hydrolytically stable phosphonic, difluoromethylphosphonic and bisphosphonic acids have been synthesized. The influence of various parameters (length of the spacer group, nature of the acidic group, and polymerizable extremity etc ) on dentin and enamel adhesion and on stability has been developped. Their photopolymerization with the N, N -diéthyl-1,3-bisacrylamidopropane (DEBAAP) has been highlighted. The impact of the acidic function on adhesive properties and chelation to hydroxyapatite has been studied via solid NMR, XPS or ICP-AES. Some of the SEA we have formulated are more efficient than the commercial ones. In self-adhesive cements field: Novel methacrylates bearing phosphonic acid functions have been prepared. Their incorporation in various proportions to a bisGMA/TEGDMA mixture has been studied. The copolymerization of these formulations has been studied by photo-DSC. Incorporation of these monomers results in an inhibition of the mixture polymerization due to the phosphonic function. Then the setup of a new self-adhesive cements has been successfully described.CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF

Synthesis and polymerization kinetics of acrylamide phosphonic acids and esters as new dentine adhesives

International audienceIn restorative dentistry, acrylamide monomers bearing phosphonic acid moieties have proved to be useful species for the formulation of dental self-etch adhesives since they provide enhanced adhesion to hydroxyapatite and are not subject to hydrolysis, thus potentially improving their adhesive durability. Previous studies have demonstrated that phosphonic acid acrylamides increase the rate of photopolymerization of diacrylamide monomers. To understand whether this rate acceleration is specific to the acrylamide function of the monomer, or due to the phosphonic acid group per se, or is applicable only with a crosslinking reaction, we have synthesized several acrylamide and methacrylate monomers bearing phosphonic acid or phosphonate moieties and studied their photopolymerization kinetics. The acrylamide phosphonic acid was found to accelerate the polymerization rate but similar monomers bearing a phosphonate ester group had a much smaller effect. A similar accelerating effect was observed when the phosphonic acid-based monomers were copolymerized with a monofunctional acrylamide monomer, excluding the possibility that the rate acceleration might be related to the crosslinking process. This rate effect is also observed when a nonpolymerizable organic phosphonic acid is present in the polymerizing medium. We suggest that the increase of the medium polarity is responsible for this rate enhancement effect

Synthesis and characterization of innovative well-defined difluorophosphonylated-(co)polymers by RAFT polymerization

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Fluorophosphonylated Monomers for Dental Applications

International audienceThe synthesis of acrylate derivatives bearing a difluorophosphonic acid function has been realized by ring-opening reaction of oxacycles and alkylation of fluorinated carbanions. Their use in self-etch adhesives is reported. The resulting adhesives based on difluorophosphonic acid monomers provide significantly higher dentin shear bond strength (SBS) than the one based on phosphonic acid, mainly due to the presence of fluorine atoms

Synthesis and evaluation of new phosphonic, bisphosphonic and difluoromethylphosphonic acid monomers for dental application

International audienceSyntheses of novel 5-(methacryloyloxy)pentylphosphonic acid 1, 5-(methacryloyloxy)pentylidenebisphosphonic acid 2 and 1,1-difluoro-5-(methacryloyloxy)pentylphosphonic acid 3 are described. The ability of these monomers to adhere to hydroxyapatite was demonstrated using 31P CP-MAS NMR spectroscopy. Their copolymerization with N,N′-diethyl-1,3-bis(acrylamido)propane (DEBAAP) was investigated with photo differential scanning calorimetry. These mixtures exhibit a significantly higher reactivity than DEBAAP alone. Bisphosphonic acid 2 was shown to be significantly more reactive than monomers 1 and 3. Adhesive properties of these monomers were also studied. Adhesives based on bisphosphonic acid 2 and difluoromethylphosphonic acid 3 provide significantly higher dentin shear bond strength than the one based on phosphonic acid 1. // New acid monomers 1-3 were successfully prepared for dental applications. The capacity of these monomers to adhere to hydroxyapatite was investigated. Photopolymerization behaviors with N,N′-diethyl-1,3-bis(acrylamido)propane were studied. Bisphosphonic acid 2 exhibited the higher reactivity among the tested monomers. The adhesive properties of monomers 1-3 were evaluated. Primers based on these new monomers were able to generate a strong bond between the tooth substance and a composite. Bisphosphonic acid 2 and difluoromethylphosphonic acid 3 gave the most promising results

Plastic scintillators with 1-phenyl-3-(mesityl)-2-pyrazoline as unique fluorophore for efficient neutron/gamma pulse shape discrimination

International audienceThe development of highly efficient plastic scintillators for neutron/gamma pulse shape discrimination is a matter of current interest. This is generally achieved using two fluorophores, with one of them being added to the polymer formulation at a concentration higher than typically 15 weight percent (wt%). Here, we report our results concerning the development of highly performant poly(vinyltoluene)-based (PVT) plastic scintillators for efficient fast neutron/gamma pulse shape discrimination, using 1-phenyl-3-(mesityl)-2-pyrazoline (1) as the only guest fluorophore. On our route during this study, the synthesis of the compound 1 has been revisited. Analysis and evaluation of the radioluminescence properties of these novel PVT-based plastic scintillators containing compound 1 are also described. In particular their light output and neutron/gamma discrimination ability were characterized. The sample doped with 15 wt% of compound 1 has a light output of 0.65 relative to EJ-200 and a neutron/gamma discrimination figure of merit of 0.84 in the range 450–500 keVee. •Efficient and inexpensive synthesis of 1-phenyl-3-(mesityl)-2-pyrazoline (PMP).•PMP as primary fluorophore of plastic scintillators for fast neutron/gamma PSD.•Polymer Characterization of highly doped PVT matrix with PMP