An efficient and multifunctional brucite/3-aminopropyltriethoxysilane (APTES)/nickel alginate/APTES (B/A/Nia/A) hybrid flame retardant was fabricated via the layer-by-layer assembly technique with brucite, silane coupling agents, nickel chloride, and sodium alginate. The morphology, chemical composition, and structure of the hybrid flame retardant were characterized. The results confirmed the multilayer structure and indicated that the assembled driving forces were electrostatic interactions, dehydration condensation, hydrogen bonds, and coordination bonds. When used in ethylene-vinyl acetate (EVA) resin, the multifunctional flame retardant had better performance than brucite in improving the flame retardancy, smoke suppression, and mechanical properties. With 130 phr loading, the multifunctional flame retardant achieved a limiting oxygen index value of 32.3% and a UL 94 V-0 rating, whereas the brucite achieved only 31.1% and a V-2 rating, respectively. The peak heat release rate and total heat released decreased by 41.5% and 8.9%, respectively. The multifunctional flame retardant had an excellent performance in reducing the smoke, CO, and CO2 production rates. These improvements could be attributed to the catalyzing carbonization of nickel compounds and the formation of more protective char layers. Moreover, the elongation at break increased by 97.5%, which benefited from the improved compatibility and the sacrificial bonds in the nickel alginate. The mechanism of flame retardant, smoke suppression, and toughening is proposed.

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Current developments of biomedical porous Ti-Mo alloysAs a biomedical hard tissue implant candidate, porous Ti-Mo alloy has received considerable attention because of its special porous structure, appropriate Young's modulus and compressive strength as well as good corrosion resistance. As a bioactive coating, hydroxyapatite is commonly used to cover the surface of bioinert metallic prostheses due to its excellent biocompatibility, bone-like structure and composition. This article reviews the current developments and the relationships between the fabrication methods, porous structure, mechanical properties, bioactive surface modification and corrosion behavior of porous Ti-Mo alloy used for hard tissue implant application. Furthermore, the future research directions are discussed to optimize the porous structure and improve the properties of porous Ti-Mo alloys.

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Abstract:Two environmental friendly triazinedithiol inhibitors 6-diallylamino-1,3,5-triazine-2,4-dithiol monosodium (DAN) and 6-dibutylamino-1,3,5-triazine-2,4-dithiol monosodium (DBN) were synthesized and their corrosion inhibition for aluminum alloy in a 1 M HCl solution was studied using weight loss methods, electrochemical measurements, and scanning electron microscopy (SEM) techniques. The inhibition efficiency of both DAN and DBN improved with increases in inhibitor concentration but decreased with increases in temperature. Results from potentiodynamic polarization and EIS showed that the corrosion inhibition efficiency of DAN and DBN was excellent. The adsorption of inhibitors on the aluminum alloy surface followed Langmuir adsorption isotherms. Morphology observation revealed that the aluminum alloy was greatly protected by these triazinedithiol inhibitors. Further, density functional theory (DFT) was used to investigate the relationships between molecular structural and inhibition efficiency.

From microstructure and technical performance of different fibers, the variation and influence of the different fibers’ properties and parameters on cryogenic properties of matrix asphalt and asphalt mixture were researched and evaluated through BBR and cryogenic trabecular bending tests. Research shows that: the addition of fibers makes the matrix asphalt’s low temperature creep stiffness S increases, creep slope m decreases, namely the matrix asphalt cryogenic flexibility and stress relaxation ability are weakened; cryogenic anti-cracking ability of asphalt mixture is significantly improved through adding different fibers, the order of improving effectiveness: Dolanit AS fiber> ARBOCEL lignin fiber> Basalt fiber; while asphalt content is constant, with the increase of fiber content, the mixture maximum bending strain, strength, deformation of mixture firstly increase and then decrease, the optimal asphalt content of asphalt mixtures and optimal fiber content of three fibers are identified according to the above three indicators’ maximum. Research points out the existed problems that are scope of application and evaluation indicators in BBR test of SHARP, optimal asphalt and fiber content are fully recommended, it provides scientific guidance and practical foundation for actual project.

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