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Nowadays, polyurethanes are produced thanks to the reaction between diol and diisocyanate species. Diisocyanate usage beeing subject to restrictions under REACH regulations due to its toxicity, many efforts are devoted to the substitution of diisocyanates for the synthesis of polyurethane. The most elegant pathway for the fabrication of isocyanate-free polyurethane is based on the reaction between CO2 and epoxide, leading to 5-membered cyclic carbonate (5CC) monomer. The 5CC reaction with diamine comonomer allows the formation of poly(beta-hydroxyurethane) polymer (PHU). However, the challenge lies in mimicking the CO2 generating isocyanate-water reaction of conventional PUs for PHU foaming. Herein, we designed a self-blowing technique thanks to in-situ generation of CO2 based on 5-membered CC reactivity. The study of model reactions confirmed the CO2 release thanks to 5CC reactivity in conventional experimental conditions. The study was then extended to linear polymer synthesis as a preliminary step to foam formulation. Basic formulation and foaming process screening were then conducted before more rigourous PHU foam samples characterisation. The effect of conventional PU additives on foam characteristics was also studied. RAMAN spectroscopy, TGA, DSC, SEM and DMA experiments were performed to state on properties of prepared NIPU foams.

NIPU --- PHU --- Non-isocyanate polyurethane --- NIPU foams --- CO2 --- Cyclic carbonate --- Self-blowing foams --- Physique, chimie, mathématiques & sciences de la terre > Chimie

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This work aims at reporting on the development of a new formulation route for a drug-eluting vaginal hydrogel implant. At this moment in time, the considered implant present on the marketplace is produced according to a strategy based on the reaction of polyols with diisocyanate, a hazardous reactant whose use is increasingly subject to strict regulation. This work targets the development of an isocyanate-free alternative formulation strategy based on the substitution of diisocyanate by a bis-cyclic carbonate which is a CO2-sourced molecule less dangerous to use. The main goals of this research will be to define the experimental conditions required to produce the bis-cyclic carbonate-based implant compatible with an application as drug eluting medical device and to determine the impact of the formulation on the physico-chemical properties and on the release profile of a model encapsulated drug. Dans ce travail, nous rapportons les avancées sur le développement d’une nouvelle voie de formulation d’un implant vaginal en hydrogel pour la libération de principe actif. Actuellement, l’implant dont il est question est synthétisé suivant une stratégie basée sur la réaction de polyols avec un di-isocyanate, un réactif dangereux qui est sujet à un nombre croissant de nouvelles régulations. Ce travail se concentre sur le développement d’une voie de formulation alternative, sans isocyanates, basée sur la substitution du di-isocyanate par un di-carbonate cyclique, une molécule CO2 sourcée moins dangereuse à employer. Les objectifs principaux de ce travail seront la détermination des conditions expérimentales optimales pour la production des implants à base de di-carbonates cycliques compatibles avec leur emploi en tant que dispositifs médicaux pour la libération de principe actif, ainsi que la détermination de l’impact de cette formulation sur les propriétés physico-chimiques de l’implant et sur le profil de relargage d’un principe actif modèle imprégné dans l’implant.

NIPU --- Drug-eluting implant --- Poly-Oxazolidone --- Physique, chimie, mathématiques & sciences de la terre > Chimie