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New synthetic strategies for molecularly imprinted polymers (MIPs) were developed to mimic the flexibility and mobility exhibited by receptor/enzyme binding pockets. The MIPs were prepared by bulk polymerization with quercetin as template molecule, acrylamide as functional monomer, ethylene glycol dimethacrylate as cross-linker, and THF as porogen. The innovative grafting of specific oligoethylene glycol units onto the imprinted cavities allowed MIPs to be obtained that exhibit extended selectivity towards template analogues. This synthetic strategy gives promising perspectives for the design of molecular recognition of molecules based on a congruent pharmacophore, which should be of interest for drug development. [ABSTRACT FROM AUTHOR]

Self‐healing polymer coatings have gained increased attention as a pathway for regenerating the inherent properties of surface following mechanical, physical or chemical damages. In most cases, the adhesion between the polymer coating layer and the substrate is driven by physical interactions. For some applications, immersing the polymer coating under water or exposing the coating to organic solvent vapors will undoubtedly lead to the coating delamination. One way to circumvent this issue is to attach the coating to the substrate via covalent bonds. However, this process will impede the self‐healing feature of the polymer coating due to the confinement of the volume change of the polymer to one dimension. Herein, surface‐attached metallo‐supramolecular polymer conetwork coatings are reported. The ability of the polymer conetworks to swell in organic solvent while maintaining their dimensional stability combined with reversible supramolecular cross‐links based on metal complexes enables the design of scratch‐healing polymer coatings. These metallo‐supramolecular polymer conetworks are prepared in a three‐step UV‐initiated polymerization reaction starting from the poly(pentafluorophenyl acrylate)‐l‐polydimethylsiloxane (PPFPA‐l‐PDMS)‐activated ester covalently attached to the substrate. Reacting the polymer conetwork coating with the 4‐(2‐aminoethyl)pyridine and cross‐linking the pyridine phases with ZnCl2 lead to the poly(N‐(2(pyridin‐4‐yl)ethyl)acrylamide‐Zn(II))‐l‐polydimethylsiloxane (PNP4EA‐Zn(II)‐l‐PDMS) polymer conetwork coatings with scratch‐healing ability. [ABSTRACT FROM AUTHOR]

The current challenge in self‐healing materials resides in the design of materials which exhibit improved mechanical properties and self‐healing ability. The design of phase‐separated nanostructures combining hard and soft phases represents an attractive approach to overcome this limitation. Amphiphilic polymer conetworks are nanostructured materials with robust mechanical properties, which can be tailored by tuning the polymer composition and chemical functionality. This article highlights the design of phase‐separated nanostructured polymers from metallo‐supramolecular amphiphilic polymer conetworks, and their application for self‐healing surfaces. The synthesis of poly(N‐(pyridin‐4‐yl)acrylamide)‐l‐polydimethylsiloxane polymer conetworks from the poly(pentafluorophenyl acrylate)‐l‐polydimethylsiloxane activated ester is presented. Loading of ZnCl2 salt into the phase‐separated polymer conetwork strengthens the network by cross‐linking the poly(N‐(pyridin‐4‐yl)acrylamide) phases, while offering reversible interactions needed for self‐healing ability. [ABSTRACT FROM AUTHOR]

Developing intrinsic self-healing polymeric materials is of great interest nowadays to extend material lifetime and/or prevent the replacement of damaged pieces. Spontaneously humidity-sensitive healable polymer network built around dynamic covalent B−O bonds was templated by using iminoboronate-based boroxine derivatives. Taking advantage of the dynamic boroxine/boronic acid equilibrium and iminoboronate chemistry, it is possible to construct polymeric materials able to self-heal without requiring any energy-demanding external activation. Interestingly, this novel family of iminoboronate adduct-based materials can be readily produced by a relatively simple and straightforward synthesis between boronic acid and diamine-based compounds, paving the way to coatings that are self-healable at ambient humidity. [ABSTRACT FROM AUTHOR]

ABSTRACT The effectiveness of hydrophobically modified nanosilica (NS) as interfacial modifying agent for immiscible polymer blends is evaluated. Blends of polypropylene (PP) with 20% of polyamide 6 (PA) and 5% hydrophobic NS were prepared by melt mixing. Compression molded sheets and extruded films were evaluated by scanning electron microscopy, transmission electron microscopy, tensile testing, and rheological measurements. Hydrophobic NS particles strongly reduce the polydispersity and droplet size of the dispersed phase, as a result of their preferential location at the interface. NS promotes outstanding stability of blend dispersion regardless of the processing or post-processing technique employed. The viscoelastic terminal zone shows a plateau for PP/PA/NS, which corresponds to a suspension-like behavior. Under large amplitude oscillatory shear, the increment in the non-linearity parameter Q evidences the interactions between NS and blend components. Therefore, NS is an excellent morphological stabilizer that prevents coalescence, but cannot promote interfacial adhesion between immiscible PP and PA phases. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 1567-1579 [ABSTRACT FROM AUTHOR]

To date, the controlled preparation of cyclic polymers is mainly achieved using click ligation strategies. The light-induced Diels-Alder click coupling has recently been shown to function as an attractive catalyst-free alternative to the copper-catalyzed alkyne-azide cycloaddition. However, the need for a light emitting system limits its applicability. To overcome this drawback, a sunlight-induced Diels-Alder reaction as an efficient route for the preparation of cyclic aliphatic polyesters in high yields and purity based on the same chemistry is demonstrated in the present contribution. The versatility and robustness of the proposed strategy against divergent atmospheric conditions is demonstrated. In light of the simplicity of the strategy presented here, it is suggested that the sunlight-induced Diels-Alder click-cyclization is a world-wide transposable process. [ABSTRACT FROM AUTHOR]