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In this work, we provide new insights into the ring-opening polymerization (ROP) of eutectic mixtures of L-lactide and ε-caprolactone that lead to the synthesis of polymer blends and a block copolymer. The influence of a set of parameters is studied to produce polyesters with tunable average-molecular weight, crystallinity, and polymer architectures with controlled degradation profiles. The outcome depends on the selection of organocatalysts, including 1,5-Diazabicyclo[4.3.0]non-5-ene (DBN), a new catalyst for the L-lactide/ε-caprolactone eutectic mixture ROP that enabled increasing the polymerization temperature. The mild polymerization temperatures and solventless conditions stand as green features of the ROP here described to prepare resorbable biomaterials with programmable degradation profiles.

In this work, we report a nonaqueous one-step method to synthesize polystyrene macroporous magnetic nanocomposites through high internal phase emulsions (HIPEs) formulated with the deep eutectic solvent (DES) composed of urea:choline chloride (U:ChCl, in a 2:1 molar ratio) as the internal phase and co-stabilized with mixtures of Span 60 surfactant and non-functionalized magnetite nanoparticles (Fe

High internal phase emulsions (HIPEs) are among complex biphasic fluids that expand on the traditional emulsion compositions, for instance, for the preparation of macroporous polymers by emulsion templating. The use of deep eutectic solvents (DESs) as the nonaqueous internal phase of HIPEs allows expanding the conditions at which polymerizations are typically carried out in aqueous HIPEs. Herein, the properties of polystyrene macroporous polymers were studied by polymerizing DES-in-oil HIPEs using choline chloride-based DESs as the internal phase. The effect of DESs’ composition – with amide, alcohol, and carboxylic acid as hydrogen bond donors – and the homogenization method used for the HIPE preparation – vortexing versus high-speed homogenizer – was studied. The stability and droplet size of HIPE precursor, as well as the macroporous structure and the mechanical properties of the synthesized polyHIPEs, are discussed.

In this work, we reported for the first time, an easy and cheap route of the synthesis of three polymerizable surfactants with a hydrotrope counterion the anilinium: dodecylsulfate (DSA), tetradecylsulfate (TSA), and hexadecylsulfate (HSA). This approach was based on a hydrolysis reaction of the sodium: dodecylsulfate (SDS), tetradecylsulfate (STS) and hexadecylsulfate (SHS) with aniline hydrochloride (AHC). Besides, we have completed the characterization, morphological and thermodynamically of the aggregates spontaneously formed in the bulk aqueous solutions for both the sodium and anilinium surfactant series. For this purpose, a combination of different experimental techniques involving density, sound velocity, electrical conductivities and surface tension of these compounds at several concentrations and temperatures were performed. The thermodynamic and morphological properties of the aqueous solutions for both surfactant series were compared and discussed on the basis of the hydrotrope effect.

In this work, the linear viscoelastic properties of the sodium dodecylsulfate/aniline hydrochloride/water system were examined in detail as a function of aniline hydrochloride (AHC) to sodium dodecyl sulfate (SDS) molar ratio (R = [AHC]/[SDS]), SDS concentration and temperature. SDS aqueous solutions undergo a structural transition from sphere to rodlike micelles and subsequently to a viscoelastic network of wormlike micelles induced by the hydrotrope AHC at low and intermediate R molar ratios (i.e., R = 0.1–0.6 for 5 wt.% SDS), which screens the repulsions between the neighboring charged head groups. The rheological response indicates that at low R molar ratios and constant surfactant concentration, the rheological behavior of the system is predominantly viscous (G′ G″) and a maximum of the absolute value of the zero frequency complex viscosity ( | η 0 * | ) is observed, which suggest that the micellar length also goes through a maximum. The region of the elastic behavior diminishes at even greater R molar ratios and a predominantly viscous behavior appears again. This drop in | η 0 * | can be attributed to the transition from linear to branched wormlike micelles that conform the tridimensional viscoelastic network. The dynamic behavior of the system was analyzed in terms of the Granek-Cates theory, which indicates that the viscoelastic network is in the slow-breaking limit. Under these conditions, reptation is found to be the controlling relaxation mechanism for this system.

The aim of this work was to determine the detailed phase behavior of the sodium dodecyl sulfate/aniline hydrochloride/water system as a function of concentration of sodium dodecyl sulfate (SDS), aniline hydrochloride (AHC) to sodium dodecyl sulfate molar ratio (R = [AHC]/[SDS]) and temperature. Phase behavior information was obtained via polarizing microscopy, differential scanning calorimetry (DSC), cryo-scanning electron microscopy (Cryo-SEM) and oscillatory linear rheological measurements with good agreement among these techniques. It is well known that SDS in water forms spherical micelles at concentrations lower than 40 wt% and temperatures above its Krafft temperature (T k = 16–21 °C). In this region, the SDS/water system exhibits Newtonian rheological behavior, which is characteristic of spherical micellar solutions. The addition of the hydrotrope, aniline hydrochloride, to SDS aqueous solutions produces a viscosity increase in this system as R augments, and a maximum of about five orders of magnitude was found at R = 0.47 for 5 wt% SDS at 20 °C. Moreover, the system shows a transition from viscous to strong viscoelastic behavior. These changes in the rheological behavior are produced by the transitions from sphere to rodlike micelles, which are induced by the hydrophobicity of AHC causing it to be absorbed into the core and the hydrophilic interface of the micelles, which screens the repulsions between the charged head groups.