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To enhance the safety grade and broaden the application scope of polypropylene in coal mines, the calcium alginate@ammonium polyphosphate@graphite microsheet (CA@APP@GM) had been synthesized and introduced into the polypropylene (PP) material to endow excellent flame retardancy, antistatic characteristics, thermostability, combustion behavior, and mechanical performance. Physical characterizations on the chemical composition and microstructure of both the gaseous and condensed phase products indicated that the phosphorus‐containing compounds were found in the char residue which were beneficial to accelerate the charring reaction to terminate the mass and heat transfer process. Hence, the CA@APP@GM executed the condensed‐phase flame‐retardant mechanism to enhance the fire resistance of PP matrix. Consequently, it is believed that the CA@APP@GM, with its remarkable flame retardancy and antistatic properties, has the potential to significantly expand the range of applications for PP materials in coal mines. [ABSTRACT FROM AUTHOR]

After the incorporation of the polyaniline (PANI), polymethyl methacrylate (PMMA) composites with outstanding electrical conductivity had been widely used in sensors. However, the flame retardancy of PMMA composites seriously restrained its further application. Thus, phosphorus‐containing polyaniline (FR‐PANI) was successfully prepared and combined with PMMA. The flame retardancy, electrical conductivity, thermal stability, and fire behavior of the resultant PMMA/FR‐PANI composites were systematically studied. When the loading amount of FR‐PANI was controlled at 20 wt%, the PMMA matrix was endowed with dramatic flame retardancy, exhibiting a limiting oxygen index of 29.1% and a UL‐94 V‐0 rating in vertical burning tests. Meanwhile, the volume resistivity was also reduced up to 0.5 MΩ. The thermal stability of the PMMA/FR‐PANI composites was enhanced by the formation of abundant char residue, which improved the fire behavior of the PMMA matrix. The effect of FR‐PANI on the flame retardancy of the PMMA matrix was deduced on the basis of thermogravimetry‐infrared, Fourier transform infrared, and scanning electron microscopic analyses. The phosphorus‐containing functional groups in the FR‐PANI molecular chain underwent thermal degradation in the condensed phase and promoted the formation of a char layer. The char layer, in turn, prevented heat transfer into the interior of the PMMA composites, serving as a barrier to the volatilization of flammable micromolecules. Therefore, FR‐PANI is an important candidate to extend the range of applications of PMMA to include multifunctional intelligent sensors. [ABSTRACT FROM AUTHOR]

The composite material of quaternary kesterite type Cu2ZnSnS4 and reduced graphene oxide (CZTS/RGO) was successfully synthesized by a one‐pot hydrothermal synthesis method. When applied as counter electrode materials for dye‐sensitized solar cells, it shows better electro‐catalytic performance towards reduction of triiodide. The DSSCs based on CZTS/RGO counter electrode shows a maximum solar‐to‐electrical power efficiency of 3.08%, which is much higher than that of pure CZTS counter electrode (1.41%) and pure RGO counter electrode (1.55%) prepared under the same conditions. The weight percent of GO to CZTS raw material used to synthesize CZTS/RGO is an important factors to affect the photovoltaic performance of DSSCs based on CZTS/RGO counter electrode. It is believed that as‐synthesized CZTS/RGO can potentially be used as alternative counter electrode materials to replace the expensive Pt counter electrode, and this one‐pot synthetic method will be helpful for exploring facile synthetic route of low‐cost and efficient CZTS based composite counter electrode materials. CZTS/RGO composite material was one‐pot synthesized. It shows better electro‐catalytic activity towards reduction of triiodide and yields higher energy conversion efficiency as a counter electrode for dye sensitized solar cells. This one‐pot synthetic method will be helpful for exploring facile synthetic route of low‐cost and efficient CZTS based composite counter electrode materials. [ABSTRACT FROM AUTHOR]

Piperazine spirocyclic phosphoramidate (PSP), a novel halogen-free intumescent flame retardant, was synthesized and used to improve the flame retardancy and dripping resistance of polypropylene (PP) combined with ammonium polyphosphate (APP) and a triazine polymer charring-foaming agent (CFA). The optimum flame-retardant formulation was PSP:APP:CFA = 3:6:2 (weight ratio). The flammability and thermal behavior of the (intumescent flame-retardant)-PP (IFR-PP) were investigated via limiting oxygen index (LOI), vertical burning tests (UL-94), thermogravimetric analysis, and cone calorimetry (CONE). The results indicated that the IFR-PP had both excellent flame retardancy and anti-dripping ability. The optimum flame-retardant formulation gave an LOI value of 39.8 and a UL-94 V-0 rating to PP. Moreover, both the heat release rate and the total heat release of the IFR-PP with the optimum formulation decreased significantly relative to those of pure PP, according to the cone calorimeter analyses. The residues of IFR-PP obtained after CONE tests were observed by scanning electron microscopy, and it was found that the char yield was directly related to the flame retardancy and anti-dripping behavior of the treated PP. J. VINYL ADDIT. TECHNOL., 20:10-15, 2014. © 2014 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]