Synthèse, polymérisation et propriétés adhésives de nouveaux monomères acides pour une application dans des matériaux dentaires

Ce mémoire est consacré à la synthèse, la polymérisation et les propriétés adhésives de nouveaux monomères acides pour une application dans les compomères et les adhésifs dentaires.Pour une application dans les compomères : de nouveaux méthacrylates porteurs de fonctions acide phosphonique ont été synthétisés par réarrangement sigmatropique [1,3] de thiophosphates de S-aryle. Ces monomères ont ensuite été introduits, dans différentes proportions, dans un mélange Bis-GMA/TEGDMA (1/1). La copolymérisation de ces formulations a été étudiée par photo-DSC. L incorporation de ces monomères acides se traduit par une diminution de la vitesse de polymérisation des mélanges. Ce phénomène est principalement dû à la présence de la fonction acide phosphonique.Pour une application dans les adhésifs dentaires : Ces travaux portent sur la synthèse et l étude des propriétés adhésives de nouveaux monomères acides en vue d une amélioration de la durabilité des adhésifs auto-mordançants (SAM). Ainsi, des SAM basés sur de nouveaux acides phosphoniques, difluorométhylphosphoniques et bisphosphoniques stables en milieu aqueux ont été mis au point. L influence sur l adhésion à la dentine de nombreux paramètres tels que la longueur du groupement espaceur, la nature de la fonction acide, ou la proportion en monomère acide, a été mise en évidence. Certains de ces adhésifs se sont avérés plus performants que des formulations commerciales.This work deals with the synthesis, the polymerization and the adhesive properties of new acidic monomers for dental applications.In compomers field: novel methacrylates bearing phosphonic acid functions have been prepared by sigmatropic rearrangement [1.3] of S-aryl thiophosphate. These acidic methacrylates have then been added, in various proportions, to a Bis-GMA/TEGDMA (1/1) mixture. Copolymerization of the formulations has been studied by photo-DSC. Incorporation of these acidic monomers results in an inhibition of the mixtures polymerization. The phosphonic acid group is mainly responsible for this behaviour.In dental adhesives field: this study deals with the synthesis and adhesive properties of new acidic monomers in order to improve self-etch adhesives (SEA) durability. Hence, SEA based on new hydrolytically stable phosphonic, difluoromethylphosphonic and bisphosphonic acids have been developed. The influence on dentin adhesion of various parameters such as the length of the spacer group, the nature of the acidic group, or the proportion in acidic monomer, has been highlighted. Some of these SEA are more efficient than the commercial onesCAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF

Synthesis, photopolymerization and adhesive properties of new hydrolytically stable phosphonic acids for dental applications

International audienceNovel monomers 2‐(N‐methylacrylamido)ethylphosphonic acid, 6‐(N‐methylacrylamido)hexylphosphonic acid, 10‐(N‐methylacrylamido)decylphosphonic acid, and 4‐(N‐methylacrylamidomethyl)benzylphosphonic acid have been prepared in good yields for use in dental adhesives. They have been fully characterized by 1H‐NMR, 13C‐NMR, 31P‐NMR, and by HRMS. All monomers are hydrolytically stable in aqueous solution. Free radical homopolymerizations of these monomers have been carried out in solution of ethanol/water (2.5/1:v/v), using 2,2′‐azo(2‐methylpropionamidine) dihydrochloride (AMPAHC) as initiator. They lead to homopolymers in moderate to excellent yields. Structure of the polymers has been confirmed by SEC/MALLS and 1H‐NMR spectra. The photopolymerization behavior of the synthesized monomers with N,N′‐diethyl‐1,3‐bis(acrylamido)propane has been investigated by DSC. New self‐etch primers, based on these acrylamide monomers, have been formulated. Dentin shear bond strength measurements have shown that primers based on (N‐methylacrylamido)alkylphosphonic acids assure a strong bond between the tooth substance and a dental composite. Moreover, the monomer with the longest spacer group provides the highest shear bond strength

UV-induced photolysis of polyurethanes

Waste production associated with the use of non-degradable materials in packaging is a growing cause of environmental concern, with the polyurethane (PU) class being notorious for their lack of degradability. Herein, we incorporate photosensitiveortho-Nitrobenzyl units into PUs to achieve controllable photodegradability. We performed their photolysis in solution and thin films which can inform the design of degradable adhesives.</p

Chain-Length-Dependent Photolysis of ortho-Nitrobenzyl-Centered Polymers

Herein, we demonstrate that the photochemical cleavage of linear polymers containing a midchain photocleavable moiety strongly depends on the chain length. Based on an ortho-nitrobenzyl (oNB) difunctional reversible addition-fragmentation chain-transfer agent, well-defined poly(methyl acrylate)s (Mn = 1.59-67.6 kg mol-1, D = 1.3-1.4) were synthesized following a core-first approach. Photolysis at λmax = 350 nm of the ortho-nitrobenzyl moiety led to the generation of equally sized polymer segments. The rate of oNB-driven polymer fragmentation, which can be well described by first-order kinetics, strongly increases with increasing molecular weight in a nonlinear fashion, potentially caused by entropic considerations and is compared to the ideal chain model. The current study thus demonstrates that polymer photolysis is dependent on the polymer chain length, with critical implications for photocleavable network design. </p

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