Cationic UV Curing of Bioderived Epoxy Furan-Based Coatings: Tailoring the Final Properties by in Situ Formation of Hybrid Network and Addition of Monofunctional Monomer

Biobased monomers are becoming essential to develop green products to substitute for petroleum-based materials. In this study, biobased monomers, such as furfuryl alcohol and 2,5-furandimethanol, are successfully functionalized with epoxy functional groups producing glycidyl furfuryl alcohol (GFA) and diglycidyl furfuryl alcohol (DGFA), respectively. Herein, DGFA is investigated as an innovative cationic UV-curable monomer for coating applications. An easy tailoring of the properties of the final UV-cured coatings is demonstrated by varying the ratio of DGFA:GFA or creating a hybrid coating by using tetraethyl orthosilicate (TEOS) as a precursor of silica to form an inorganic network. Real-time Fourier transform infrared spectroscopy is used to monitor the cationic photopolymerization of DGFA formulations. Finally, glass transition, contact angle, thermal stability, and mechanical properties are investigated as a function of TEOS and GFA content in DGFA formulations. The thermal mechanical behavior is studied by dynamic mechanical thermal analysis. The thermal properties of the networks are analyzed by dynamic scanning calorimetry and thermogravimetric analysis

Kinetics of doublet formation in bicomponent magnetic suspensions: The role of the magnetic permeability anisotropy

Micron-sized particles (microbeads) dispersed in a suspension of magnetic nanoparticles, i.e., ferrofluids, can be assembled into different types of structures upon application of an externalmagnetic field. This paper is devoted to theoretical modeling of a relative motion of a pair of microbeads (either soft ferromagnetic or diamagnetic) in the ferrofluid under the action of applied uniform magnetic field which induces magnetic moments in the microbeads making them attracting to each other. The model is based on a point-dipole approximation for the magnetic interactions between microbeads mediated by the ferrofluid; however, the ferrofluid is considered to possess an anisotropic magnetic permeability thanks to field-induced structuring of its nanoparticles. The model is tested against experimental results and shows generally better agreement with experiments than the model considering isotropic magnetic permeability of ferrofluids. The results could be useful for understanding kinetics of aggregation of microbeads suspended in a ferrofluid. From a broader perspective, the present study is believed to contribute to a general understanding of particle behaviors in anisotropic media.This work was supported by Project No. FIS2013-41821-R (Ministerio de Economía y Competitividad, Spain; cofunded by ERDF, European Union). P.K. acknowledges financial support of the French government, piloted by the National Research Agency (ANR) in the framework of the project Future Investments UCAJEDI, Ref. No. ANR-15-IDEX-01 (ImmunoMag and RheoGels). A.Z. acknowledges the Russian Fund for Basic Research (Project Ref. 16-58-12003), as well as the Program of the Russian Federation Ministry of Science and Education (Project Ref. 3.1438.2017/4.6)

Towards increased sustainability for aromatic polyesters: Poly(butylene 2,5-furandicarboxylate) and its blends with poly(butylene terephthalate)

Eco-friendly engineering polyesters originating from monomers derived from biomass such as 2,5-furandicarboxylic acid (2,5-FDCA), constitute a family of materials that have recently attracted immense interest from industry and academia. Herein, poly(butylene 2,5-furandicarboxylate) (PBF) was synthesized by the melt polycondensation method and PBF-based blends have been prepared with its terephthalate counterpart, poly(butylene terephthalate) (PBT). Τhe X-ray diffraction patterns of the as-prepared blends revealed the presence of mixtures of crystals of the blend components. A detailed study of the thermal properties of the homopolymers and the blends was performed by employing both conventional and fast scanning calorimetry in an attempt to obtain amorphous samples, to reveal the glass transitions of the samples and export conclusions regarding their miscibility. The isothermal and dynamic crystallization of the samples was thoroughly studied along with the evaluation of multiple melting behaviour by applying conventional and fast scanning rates. In addition, reactive blending was investigated in order to improve the miscibility of the blends

Monitoring grease production by reaction calorimetry and thermoanalytical methods as an alternative to dropping point determination

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