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Several difunctional oligomers were synthesized by functionalizing perfluoropolyalkylether (PFPAE) chains with different vinyl ethers and epoxides end-groups. Due to their innate synthetic challenges and demanding purification protocols, the PFPAE derivatives were obtained in low yield and with an average functionality lower than 2. However, the functionalized PFPAE oligomers were successful in being used in photo-induced cationic polymerization processes, obtaining transparent and soft films. The influences of the fluorinated chains, and various end-groups on the photopolymerization process were investigated, as well their chemical stability, thermal degradation, and surface properties. [ABSTRACT FROM AUTHOR]

New perfluoropolyalkylether (PFPAE) monomers, chain extended with different alkyl groups and functionalized with vinyl ether or epoxide end-groups, were employed, together with trimethylolpropane trivinyl ether or trimethylolpropane triglycidyl ether, to produce fluorinated copolymers. The photoinduced cationic polymerization was investigated, and the PFPAE-based copolymer properties were thoroughly characterized. Interesting surface properties and two different values of refractive index were observed: thus, these fluorinated copolymers can be suitable materials for the manufacture of self-cleaning coatings and optical waveguides. [ABSTRACT FROM AUTHOR]

Two chaperonopathies have been linked to mutations in the human hsp60 (hHsp60 ; HSPD1) gene, but other existing variants might cause diseases, even if there is no comprehensive information about this possibility. To fill this vacuum, which might be at the basis of misdiagnoses or simply ignorance of chaperonopathies in patients who would benefit by proper identification of their ailments, we searched the sequenced human genomes available in public databases to determine the range of missense mutations in the single hsp60 gene. A total of 224 missense mutations were identified, including those already characterized. Detailed examination of these mutations was carried out to assess their possible impact on protein structure-function, considering: (a) the properties of individual amino acids; (b) the known functions of the amino acids in the human Hsp60 and/or in the highly similar bacterial ortholog GroEL; (c) the location of the mutant amino acids in the monomers and oligomers; and (d) structure-function relationships inferred from crystal structures. And we also applied a bioinformatics tool for predicting the impact of mutations on proteins. A portion of these genetic variants could have a deleterious impact on protein structure-function, but have not yet been associated with any pathology. Are these variants causing disease with mild clinical manifestations and are, therefore, being overlooked? Or are they causing overt disease, which is misdiagnosed? Our data indicate that more chaperonopathies might occur than is currently acknowledged and that awareness of chaperonopathies among medical personnel will increase their detection and improve patient management. [ABSTRACT FROM AUTHOR]

We demonstrate how to tune the surface chemistry and properties of copolymers obtained by the photopolymerization of polyoxyethylene (meth)acrylic monomers and a low polarity siloxane comonomer which spontaneously migrates to the free surface. By controlling the photopolymerization conditions, such as the light gradient through the thickness of the film and selecting the proper monomer functionality, it is possible to optimize and photoenforce the surface segregation of the siloxane comonomer. Photocured films containing the same amount of siloxane component (1 wt %) can exhibit a surface energy ranging from 42 to 22 mN m-1 depending on the process conditions. XPS and AFM analyses confirm that polymers with a compositional gradient are obtained and that the surface segregation can be finely photocontrolled. Photopolymerization is thus proven to be a facile, single step method for generating gradient films and for independently and simultaneously tune their surface and bulk properties. [ABSTRACT FROM AUTHOR]

We introduce a series of 'minimal' models to describe a common light-driven directional solidification process, known as frontal photopolymerization ( FPP), focusing on experimental observables: the solidification kinetics, light attenuation and spatiotemporal monomer-to-polymer conversion. Specifically, we focus on FPP propagation that yields conversion profiles that are not invariant with time, and which cannot be simply described by the presence of mass or heat diffusion. The models are assessed against experimental data for the photopolymerization of a model trimethacrylate system. We find that the simplest model, comprising a single equation of motion for the conversion fraction ϕ and a generalized Beer-Lambert law, can only describe the experimental data by assuming an unphysical variation in optical absorption. Introducing a ϕ-dependent reaction constant Keff is found to require a time dependence, regardless of the functional form in ϕ. We conclude by introducing a 'minimal' chemical model, which is based on a simple three-step reaction scheme involving the spatiotemporal evolution of the photoinitiator fraction, relative fraction of radicals and monomer conversion fraction, that is able to capture the experimental data with a small number of parameters and under reasonable FPP assumptions. Our framework provides important predictive ability for ubiquitous solidification and patterning processes, including three-dimensional printing, via photopolymerization. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The article discusses a study on the synthesis of photopolymerizable fluorinated monomers and oligomers. Topics covered include the strategies of fluoroacrylates, fluoroepoxides, and fluorinated photoinitiators, the application in coatings and adhesives, replica molding materials, and self-healing polymers, and the properties of fluromonomers such as chemical inertness, hydrophobicity, and thermal, mechanical, and radiation resistance.

Frontal photopolymerization (FPP) is a versatile directional solidification process that can be used to rapidly fabricate polymer network materials by selectively exposing a photosensitive monomer bath to light. A characteristic feature of FPP is that the monomer-to-polymer conversion profiles take on the form of traveling waves that propagate into the unpolymerized bulk from the illuminated surface. Practical implementations of FPP require detailed knowledge about the conversion profile and speed of these traveling waves. The purpose of this theoretical study is to (i) determine the conditions under which FPP occurs and (ii) explore how optical attenuation and mass transport can be used to finely tune the conversion profile and propagation kinetics. Our findings quantify the strong optical attenuation and slow mass transport relative to the rate of polymerization required for FPP. The shape of the traveling wave is primarily controlled by the magnitude of the optical attenuation coefficients of the neat and polymerized material. Unexpectedly, we find that mass diffusion can increase the net extent of polymerization and accelerate the growth of the solid network. The theoretical predictions are found to be in excellent agreement with experimental data acquired for representative systems. [ABSTRACT FROM AUTHOR]

Perfluoropolyethers ( PFPEs) functionalized with acrylic and methacrylic end groups can be mixed with typical hydrogenated acrylic monomers such as hexanediol diacrylate, tripropyleneglycol diacrylate and trimethylolpropane triacrylate. Mixtures are transparent up to 1:3 weight ratios and can then be photopolymerized. Crosslinked networks are obtained, showing a complex multiphasic nanostructure: submicrometric hydrogenated nanodomains are chemically linked to the fluorinated matrix. Because of this morphology, these networks show peculiar bulk and surface properties: the PFPE matrix ensures low surface energy and low refractive index, while the hydrogenated phase enhances the mechanical properties and polarity of the systems. The networks are then suitable for advanced applications in coatings, microelectronics and optical devices. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Biobased monomers and green processes are key to producing sustainable materials. Cardanol, an aromatic compound obtained from cashew nut shells, may be conveniently functionalized, e.g., with epoxy or (meth)acrylate groups, to replace petroleum-based monomers. Photoinduced polymerization is recognized as a sustainable process, less energy intensive than thermal curing; however, cardanol-based UV-cured polymers have relatively low thermomechanical properties, making them mostly suitable as reactive diluents or in non-structural applications such as coatings. It is therefore convenient to combine them with biobased reinforcements, such as microfibrillated cellulose (MFC), to obtain composites with good mechanical properties. In this work a cardanol-based methacrylate monomer was photopolymerized in the presence of MFC to yield self-standing, flexible, and relatively transparent films with high thermal stability. The polymerization process was completed within few minutes even in the presence of filler, and the cellulosic filler was not affected by the photopolymerization process. [ABSTRACT FROM AUTHOR]

This article reports the synthesis of a novel perfluoropolyalkylether (PFPAE) vinylether monomer and its use as a comonomer in the thiol‐ene photopolymerization of a trifunctional thiol together with a trifunctional vinylether. The crosslinked copolymers are obtained in the form of few mm thick layers and characterized. By changing the thiol/ene ratio, the polymers are optimized to tailor their surface composition and obtain adhesion between two thick layers despite the presence of the fluorinated monomer. The final bilayered structures are adhesive, and appeared chemically resistant, with good dimensional stability: therefore, these fluorinated thiol–ene based copolymers are likely to be of interest for applications based on layer‐by‐layer processes, such as additive manufacturing and microfluidics. [ABSTRACT FROM AUTHOR]

Disulfide-containing coatings are gaining importance due to the peculiar properties and responsiveness of S S bonds, which make them suitable for several applications, first among them self-healable materials. Herein, a novel UV-curable diacrylated polyurethane monomer containing disulfide bonds (DSPDA) was synthesized through a one-step process without the need for further purification, as assessed by NMR and HPLC analyses. The photopolymerization kinetics of the monomer was studied through real-time FTIR, highlighting a fast and complete conversion even in the absence of a photoinitiator, thus demonstrating the self-initiating capabilities of the synthesized monomer based on the disulfide cleavage upon UV light exposure. Clear coatings having a T g = 72 °C were obtained. The self-healing ability of the films was assessed: thanks to the presence of disulfide bonds in the cured coating, a recovery of the damage was obtained in only 10 min by heating at 100 °C. • Synthesis of novel photocurable disulfide-containing diacrylate monomer • Self-initiating photopolymerization exploiting disulfide photocleavage • Production of clear and transparent coatings • Self-healing of the coating by thermally induced metathesis of disulfide bonds [ABSTRACT FROM AUTHOR]