No abstract

No abstract

A novel phosphorus‐containing, nitrogen‐containing, and sulfur‐containing reactive flame retardant (BPD) was successfully synthesized by 1‐pot reaction. The intrinsic flame‐retardant epoxy resins were prepared by blending different content of BPD with diglycidyl ether of bisphenol‐A (DGEBA). Thermal stability, flame‐retardant properties, and combustion behaviors of EP/BPD thermosets were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), limited oxygen index (LOI) measurement, UL94 vertical burning test, and cone calorimeter test. The flame‐retardant mechanism of BPD was studied by TGA/infrared spectrometry (TGA‐FTIR), pyrolysis‐gas chromatography/mass spectrometry (Py‐GC/MS), morphology, and chemical component analysis of the char residues. The results demonstrated that EP/BPD thermosets not only exhibited outstanding flame retardancy but also kept high glass transition temperature. EP/BPD‐1.0 thermoset achieved LOI value of 39.1% and UL94 V‐0 rating. In comparison to pure epoxy thermoset, the average of heat release rate (av‐HRR), total heat release (THR), and total smoke release (TSR) of EP/BPD‐1.0 thermoset were decreased by 35.8%, 36.5% and 16.5%, respectively. Although the phosphorus content of EP/BPD‐0.75 thermoset was lower than that of EP/DOPO thermoset, EP/BPD‐0.75 thermoset exhibited better flame retardancy than EP/DOPO thermoset. The significant improvement of flame retardancy of EP/BPD thermosets was ascribed to the blocking effect of phosphorus‐rich intumescent char in condensed phase, and the quenching and diluting effects of abundant phosphorus‐containing free radicals and nitrogen/sulfur‐containing inert gases in gaseous phase. There was flame‐retardant synergism between phosphorus, nitrogen, and sulfur of BPD.

A structural unit showing a specific function can serve as a functional unit, ranging from atom/molecule system to microscale object. [3] Self-assembly refers to the fact that functional units spontaneously form well-ordered structures, which is ubiquitous in nature, like high-strength nacre, highly anisotropic and strong muscles, self-cleaning lotus effect. [4][5][6][7] The secret of these unique properties is the well-ordered structures formed by self-assembly process. Inspired by this, self-assembled artificial materials with revolutionary performances hold great promise in the field of energy storage and conversion. [8][9][10] In this regard, the incorporated ionic conductors in composite polymer electrolytes can be considered as functional units, which have been used to improve electrochemical properties, structural stability, and mechanical robustness. [11][12][13] Conventionally, the most incorporated ionic conductors are ceramic particles, such as perovskite-type Li 0.33 La 0.557 TiO 3 (LLTO), [14] garnet-type Li 7 La 3 Zr 2 O 12 (LLZO), [15] NASICON-type Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP), Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP). [16] Recently, MOF impregnated with ionic liquid (IL) or liquid electrolyte has been served as a novel ionic conductor due to its internal massive pores, which can provide wellordered ion pathways. [17][18][19][20] And some MOF materials are used as fillers for solid polymer electrolytes to enhance the ionic conductivity. [21] However, these discrete particles in polymer electrolytes usually lead to insufficient ionic conductivity improvement because of the isolated and discontinuous lithium ions channels. [22,23] Based on this, 1D ionic conductors with high aspect ratio have been designed and fabricated for extended ions pathways, such as nanowires, [24] nanofibers, [25] and nanotubes. [26] Unfortunately, the ionic conductivity enhancement is still limited, because the obtained composites are fabricated by incorporating above powders into polymer electrolytes, in which these incorporated powders are prone to aggregate and precipitate along with solvent volatilization in the film-forming process, leading to heavy barriers for continuous ion conduction. [27][28][29] In addition, the randomly distributed powders in polymer electrolytes fail to provide strong support for lithium dendrite suppression.In order to overcome the issues of randomly distributed powders, some researchers pay attention to the spatial arrangement of incorporated ceramics in composite polymer Composite solid electrolytes have attracted significant interest because they overcome the defects of single-component solid electrolytes. However, the discontinuous ion transport and weak mechanical support caused by randomly distributed powders lead to inferior ionic conductivity and poor mechanical strength. Herein, a hierarchically self-assembled metal-organic framework (MOF) network is designed to provide continuous ion transport and mechanical support for composite polymer electrolytes. This unique structure is ac...

HAdV-56 is a new recombinant type isolated from epidemic keratoconjunctivitis (EKC) patients and has been sporadically isolated in Japan several times. Here, an outbreak of EKC in the city of Dalian, China involving a large number of workers in two factories was reported; this was the first outbreak of EKC associated with HAdV-56 worldwide.