Summary: In this work, we report the synthesis of a great variety of polycations with varying counter‐anions. These new polymers were obtained by a simple anion exchange reaction facilitated by the phase separation of the resulting products. This strategy has been successfully applied to three different polycations, poly(1‐vinyl‐3‐ethylimidazolium bromide) poly(ViEtIm+Br−), poly(1‐ethyl‐4‐vinylpyridinium bromide) poly(ViEtPy+Br−), and poly(methacryloyloxyethyltrimethylammonium chloride) poly(EMTMA+Cl−), with seven counter‐anions such as PF, CF3SO, (CF3SO2)2N−, (CF3CF2SO2)2N−, dodecylbenzenesulfonate, toluene‐4‐sulfonate, and bis(2‐ethylhexyl) hydrogen phosphate. The solubility range of the new polymeric ionic liquids becomes very broad, including apolar organic solvents and ionic liquids, depending on the nature of the counter‐anion. Thermogravimmetric experiments showed that the thermal stability of the PILs also depends on the nature of the counter‐anion improving in the order CF3SO > (CF3CF2SO2)2N− > C12H25C6H4SO > PF > Br− > C16H34PO.A simple anion exchange procedure similar to the reaction used in ionic liquids chemistry is used to the synthesis of new polymeric ionic liquids (PILs).magnified imageA simple anion exchange procedure similar to the reaction used in ionic liquids chemistry is used to the synthesis of new polymeric ionic liquids (PILs).

Since polyol is one of the major components in polyurethane foam synthesis, introducing renewably sourced polyols in the foam formulation leads to materials with high renewable carbon content. A series of flexible polyurethane foams with variations in polyol composition were synthesized with castor oil based Lupranol Balance ® 50 polyether polyol and corn based polytrimethylene ether glycol mixtures. Water was used as the unique and eco-friendly blowing agent. The effect of the relative amount of each polyol on the structure and properties was analyzed by optical microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, tensile and compressive tests, dynamic mechanical analysis and atomic force microscopy. The average molecular weight and hydroxyl number of the polyol components showed to influence the foaming reaction and hence the structure and properties of the polyurethane foam. The newly developed peak force quantitative nano-mechanics technique was used to map the elastic modulus values of foam cell struts and it seemed to be adequate to assess the purity of the different phases.

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A series of Prussian blue analogues, RbxMn[Fe(CN)6]y·zH2O with different stoichiometries have been synthesized. Elemental analyses reveal a quasilinear decrease in x and y when z increases. Some of these samples present a first‐order phase transition between the MnII–FeIII and MnIII–FeII electronic states with large thermal hysteresis loops observed in the magnetic susceptibility. The phase‐transition temperatures correlate with the stoichiometry, but quantitative predictions cannot be made because of the disordered nature of the compounds. Contrary to previous literature reports, calorimetric and Raman spectroscopic measurements reveal that the charge‐transfer phase transition is accompanied by a significant entropy change, ΔS = 48–59 J K–1 mol–1, of mainly vibrational origin. In addition to the thermal phase transition, Raman spectra also show that below ca. 120 K a photoinduced MnIII–FeII to MnII–FeIII conversion occurs in certain stoichiometries.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Sterilization with ethylene oxide (EO) and gas plasma (GP) are well-known methods applied to ultra-high molecular weight polyethylene (UHMWPE) surfaces in the belief that they prevent major material changes caused by gamma irradiation. However, the influence of these surface sterilization methods on bacterial adherence to UHMWPE is unknown. UHMWPE samples with various degrees of roughness (0.3, 0.8 and 2.0 μm) were sterilized with either GP or EO. The variations in hydrophobicity, surface free energy and surface functional groups were investigated before and after sterilization. Sterilized samples were incubated with either Staphylococcus aureus or Staphylococcus epidermidis in order to study bacterial adherence to these materials. Fewer bacteria adhered to UHMWPE after sterilization with EO than after sterilization with GP, especially to the smoothest surfaces. No changes in chemical composition of the UHMWPE surface due to sterilization were observed using X-ray photoemission spectroscopy analysis. The decreased bacterial adherence to UHMWPE found at the smoothest surfaces after sterilization with EO was not directly related to changes in chemical composition. Increased bacterial adherence to rougher surfaces was associated with increased polar surface energy of EO-sterilized surfaces.

Two sets of new thermoplastic elastomeric polyurethanes were prepared by different routes. One route was the common two shoot polymerization, in which a short diol is added at the last step in order to link prepolymer chains. The new rout that is described here consisted in preparing firstly the hard segments upon 1,6-hexamethylene diisocyanate (HDI) and 1,4-butanediol (BD), used in the previous case as chain extender, and adding finally the polydiol in the second step, in a chain extender fashion, in order to form the grown polyurethane. The differences between these two sets of materials were considerable due to the more ordered and crystalline hard segments formed and the subsequent nano-domain distribution that aroused when inverting the common synthesis. Inter-domain distances and domains sizes are measured and also compared with those of the literature. The structure/properties relationships of synthesized polyurethanes with different hard segment content were analyzed by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), atomic force microscopy (AFM), and performing tensile and Shore D hardness tests.

The gradient on block copolymer concentration through film thickness as well as the effects of casting solvents used on the nanostructuring of a thermosetting epoxy coating modified with an epoxidized poly­(styrene-b-butadiene-b-styrene) (SBS) triblock copolymer was studied by means of atomic force microscopy and attenuated total reflectance infrared spectroscopy. Thin coating films based on a commercial epoxy– amine formulation consisting of diglycidyl ether of bisphenol A and a low-temperature fast curing amine were modified with several amounts of epoxidized SBS triblock copolymer. Toluene and a mixture of tetrahydrofuran and N,N-dimethylformamide were used as casting solvents. With epoxidation degrees higher than 45 mol % of polybutadiene block nanostructuring was achieved. Fast curing rate of the epoxy/amine system and the comparatively slow evaporation rate of the casting solvent led to a gradient of morphologies through the film cross section owing to the coalescence of small micelles into larger micellar domains in the case of low block copolymer content. For these reasons, different morphologies were also obtained in the midtransverse section of a film with variable thickness. Finally, pseudolamellar nanostructure at high copolymer contents was achieved as confirmed by parallel and perpendicular cuttings to the air/polymer interface.

We report an approach for the design of nanostructured thermoplastic elastomeric materials consisting of poly­(styrene-b-butadiene-b-styrene) and epoxy. This approach consists in the epoxidation of PB block and further mixing with low contents of the DGEBA:MCDEA system. Morphological behavior as well as thermal and mechanical properties have been investigated. The modification of epoxidized SBS with 10, 20, and 30 wt % epoxy system induces microphase separation at nanoscale from a poorly to well-ordered self-assembled morphology where the shape of these structures depends greatly on the mixture compositions, showing a transition from worm-like to lamellae. The generated nanostructures are accessible owing to the miscibility between the epoxidized PB block and the epoxy system that have been confirmed by an increment on the T g (before and after curing) of this block in the mixture. The mixing produces a significant increase on strength and stiffness being more relevant in the system with 30 wt % epoxy and well-ordered lamellar morphology.