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Nanoparticles with core-shell structure provide a new potential technology to improve the efficiency of flame retardants. Using nanometer antimony trioxide particles (nano-Sb2O3) as matrix material and brominated bisphenol-A epoxy vinyl ester resin (Br-VERs) diluted by toluene (PhMe) or styrene (ST) as the coating material, PhMe-nano-Sb2O3@Br-VERs and ST-nano-Sb2O3@Br-VERs core-shell composite particles were prepared by electromagnetic stirring method. The results show that Br-VERs can successfully coat on the surface of nano-Sb2O3, thus forming core-shell composite particles with crystalline nano-Sb2O3 as the core and amorphous Br-VERs as the shell. The thickness of Br-VERs shell of PhMe-nano-Sb2O3@Br-VERs composite particles is between 9.5 nm and 15.5 nm, and the shell's mass fraction is 20.8% in the composite particles. The thickness of Br-VERs shell of ST-nano-Sb2O3@Br-VERs composite particles is between 5.5 and 9.5 nm, and the shell's mass fraction is 3.8%. The mass of Br-VERs shell of PhMe-nano-Sb2O3@Br-VERs composite particles is 5.47 times that of ST-nano-Sb2O3@Br-VERs composite particles, which indicates PhMe used as the diluent for Br-VERs has a better effect than that of ST used as the diluent. [ABSTRACT FROM AUTHOR]

Sb2O3 nanoparticles (nano-Sb2O3), montmorillonite (MMT) and brominated polystyrene (BPS) were used to enhance flame retardancy of polypropylene (PP) in the work, in which nano-Sb2O3 was modified by cetyl trimethyl ammonium bromide and polyethylene glycol and MMT was modified by silane coupling agent. PP matrix flame retardant composites were prepared by melt blending after pre-mixing by high energy ball milling technique. Then, the flame retardancy, thermal stability behaviour, crystallization performance and tensile strength of PP matrix composites (nano-Sb2O3/MMT/BPS-PP, nano-Sb2O3/BPS-PP) were investigated. The results show that MMT can significantly improve the thermal stability and flame retardancy of PP matrix due to improving the strength of char layer and forming barrier effect. Compared with 3.5%nano-Sb2O3/8%BPS-PP composites, the limiting oxygen index of 3.5%nano-Sb2O3/3%MMT/8%BPS-PP composites was increased from 26.9% to 29.0% and its UL94 grade was achieved to V-0 level. Moreover, MMT and nano-Sb2O3 can increase the crystallinity and tensile strength of PP matrix composites because of the heterogeneous nucleation effect of MMT and nano-Sb2O3 particles on the crystallization of PP matrix. [ABSTRACT FROM AUTHOR]

Poor dispersion of nanoparticles in polymer matrix would limit the development and application of particulate-filled polymer composites. Therefore, the Sb2O3 nanoparticles were functionalized by a combination of cetyltrimethyl ammonium bromide (CTAB) and silane coupling agent KH-560 via water bath modification method so as to improve the dispersion of Sb2O3 nanoparticles in poly(butylene terephthalate) (PBT) matrix and enhance the interfacial adhesion between nanoparticles and polymer matrix. Besides, the coating efficiency of compound modifiers on the surface of Sb2O3 nanoparticles was characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA). The Sb2O3 nanoparticles with different morphologies were systemically measured using transmission electron microscopy and dynamic light scattering measurement. The effects of particle surface treatment, particle size, particle morphology and particle loading on mechanical properties of composites were studied by the X-ray diffraction (XRD), tensile test machine and impact strength machine. The tensile strength of nanocomposites gradually increases with decreasing the particle size at the same amount of Sb2O3 nanoparticle fillers, which is attributed to improvement of interfacial contact area and stronger interfacial adhesion between Sb2O3 nanoparticles and PBT matrix. And the compound modified Sb2O3 nanoparticles are homogeneously dispersed in PBT matrix and play an important role in the properties enhancement. Moreover, taking consideration of the tensile and impact strengths, the optimal loading is 3 wt%. [ABSTRACT FROM AUTHOR]