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• Vitrimer has higher thermal stability but lower fire performance than epoxy. • Melting above vitrimer transition temperature affects LOI and UL-94 results. • From 2% phosphorus content, rapid charring prevents the melting of vitrimers. • The same flame retardants perform better in vitrimers than in PER epoxy. • Imine type vitrimers leverage the phosphorus-nitrogen synergism. We developed flame retarded polyimine type vitrimers and carbon fibre reinforced composites using two additive and a reactive flame retardant containing phosphorus: ammonium polyphosphate (APP), resorcinol bis(diphenyl phosphate) (RDP); and N,N',N "-tris(2-aminoethyl)-phosphoric acid triamide (TEDAP). We characterised the vitrimer matrix materials by differential scanning calorimetry (DSC), thermal analysis (TGA), limiting oxygen index (LOI), UL-94 test and mass loss calorimetry (MLC), while the vitrimer composites by LOI, UL-94 test, MLC and dynamic mechanical analysis (DMA). We compared the performance of the vitrimer systems to a benchmark pentaerythritol-based aliphatic epoxy resin system (PER). The vitrimer reference had higher thermal stability but lower fire performance than the PER aliphatic reference epoxy. At lower phosphorus content, the vitrimer systems exhibited a melting above their vitrimer transition temperature, which negatively affected their LOI and UL-94 results. From 2% phosphorus content, rapid charring and extinguishing of vitrimers prevented the softening and deforming. The superior performance of these same flame retardants in vitrimer systems could be attributed to the high nitrogen content of imine-based vitrimers in combination with phosphorus flame retardants, exploiting nitrogen-phosphorus synergism. In both matrices, flame retardants with solid phase action lead to better fire performance, while in composites, the lowest peak heat release rates (152 kW/m2 in vitrimer composite) were achieved with RDP acting predominantly in the gas phase, as carbon fibres hindered the intumescent phenomenon. [Display omitted] [ABSTRACT FROM AUTHOR]

The rate of restenosis can be decreased by the usage of drug eluting stents compared to bare metal stents. The aim of this work was the optimization of micro sprayed polymer coatings for medical applications and the examination of drug absorbing and releasing properties of these coatings. Control groups were bare metal stent models (316 LVM type austenitic stainless steel tube slices). Different types of medical grade polyurethane granules were applied onto the stent surface. Various methods were used for the examination of the surface and coating quality, such as optical microscopy, scanning electron microscopy and atomic force microscopy.

By choice of appropriate reaction conditions, the phosphorylation of hydroquinone by diethyl chlorophosphate gave predominantly the monophosphate (2). A similar reaction of phloroglucinol led to the mixture of the possible products (6, 7, and 8). The monophosphinylation of the above hydroxyphenols by diphenylphosphinyl chloride could be accomplished with a good selectivity to give product 4or 9, the yields, however, being variable. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:126–130, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10006

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