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International audienceThe synthesis of Diels-Alder (DA) adducts from stoichiometric quantities of a new multi-maleimide dienophile and epoxy-amine type oligomers bearing furan group units on their side chains was investigated. Precursors of the DA reaction were first synthesized and their functionalities were determined by 1H NMR and gel permeation chromatography/SEC analysis. TGA and DSC were used to characterize their thermal properties. In this study, the effect of the multi-furan diene functionality on the network density was analyzed. Rheological analysis was used to highlight the thermal reversibility of the DA reaction and to calculate the average molar weight between crosslinks. The results showed that network density could be regulated or modulated by varying the functionality of the diene

Currently, there is very strong interest to replace synthetic polymers with biological macromolecules of natural source for applications that interact with humans or the environment. This research describes the development of drug delivery hydrogels from natural polymers, starch, lignin and hemicelluloses by means of reactive extrusion. The hydrogels show a strong swelling ability dependent on pH which may be used to control diffusion rates of water and small molecules in and out of the gel. Also the hydrogels degradation rates were studied in a physiological solution (pH 7.4) for 15days. The results indicated that for all three macromolecules, lower molecular weight and higher level of plasticizer both increase the rate of weight loss of the hydrogels. The degradation was extremely reduced when the polymers were extruded in the presence of a catalyst. Finally the dynamic mechanical analysis revealed that the degradation of the hydrogels induce a significant reduction in the compressive modulus. This study demonstrates the characteristics and potential of natural polymers as a drug release system.

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International audiencePoly(epsilon-caprolactone) (PCL)-based thermoreversible networks with self-healing properties were prepared through DielsAlder (DA) and retro-DA reactions. Bis- or Tris-maleimide compounds and a series of copolymer(caprolactone-diene) PCLXFY (X: degree of polymerization and Y: furan-average functionality) with Y between 2.4 and 4.9 were used. The successive sequences of formation and dissociation of polycaprolactone networks via DA and retro-DA reactions were observed repeatedly by dynamic mechanical analyses (DMA) and their gel-temperatures determined. The cross-linking densities, thermal properties, and thermal reversibility of the PCLXFY/multimaleimide polymers have been modulated by the structure and functionalities of the used diene and dienophile moieties

To cite this version:Corinne Jegat, Nathalie Mignard. Effect of the polymer matrix on the thermal behaviour of a furanmaleimide type adduct in the molten state.. Polymer Bulletin, Springer Verlag, 2008, 60 (6) SummaryThe effect of three different polymer matrices on the stability of the exo-adduct formed from N-Phenylmaleimide (PM) and furfuryl alcohol (FAl) toward retro DielsAlder reaction was studied. First, a stereospecific synthesis of the exo-adduct was carried out at the condensed state and for a best understanding, its thermal properties was reported. The temperature of the rDA reaction of the exo-adduct in polyolefins (a low density polyethylene and a random copolymer of ethylene and glycidyl methacrylate) was found similar to the pure exo-adduct rDA reaction temperature. In a poly(vinylacetate)-g-polycaprolactone matrix this temperature was distinctly lower. In this last matrix, the reversibility of the rDA reaction was proved by the formation of the endo-adduct FAlPM during cooling.