| Zinc Borates (ZB) with different nano-morphologies were successfully synthesized by using triethanolamine (TEA) as the surfactant in this thesis. The effects of the addition agent, the ratio of reactants, the stirring speed, the temperature and the time of reaction on the yield and diameter of ZB were studied to choose the proper synthesis conditions. The ZB were used for the flame-retardant of polypropylene (PP) composites composed of PP/APP/PER/ POE-g-MAH. The structure and morphologies of ZB are investigated by elements analysis, powder X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometer (EDS), transmission electron microscope (TEM) and thermal analysis (TG) and differential scanning calorimetry (DSC). The mechanical property, thermal property and flame retardancy of ZB/APP/PER/PP were also studied.1. A new surfactant triethanolamine (TEA) was successfully chosen to synthetize nano-particle Zinc Borate using ZnSO4·H2O and Boric acid as row materials. The molar ratio of reactants and dosage of TEA have significant effects on nano-morphologies. The best synthesis conditions were as follows:the molar ratio of Zn(NO3)2·H2O and H3BO3 was 1/2, the reaction temperature was 80℃, and the reaction time was 12h. The as-prepared materials displayed nanostrips with average length from 100 to 200nm and the diameter about 30nm when the dosage of TEA was 2%, while nanoflakes with length/width about 4μm and thickness about 10nm when the dosage of TEA was 4%.2. The study on the reaction mechanism of solution using triethanolamine as surfactant indicated that the surfactant triethanolamine was beneficial to both the form of microemulsion and nano-zinc borate.3. Using POE-g-MAH as a compatibilizer, ammonium polyphosphate (APP) as flame retardant, the mechanical properties, the flame retardants of APP/pentaerythritol (PER)/PP composite IFR and PP has been tested by tensile strength method, flexural strength method, elongation at break method and non-totched strength method; extreme oxygen index method (LOI) and UL94 vertical combustion method. The result shows that POE-g-MAH could enhance the affinity between flame retardants and PP significantly. The tensile strength of and flexural strength of the composite was maximum when the addition amount of POE-g-MAH was 3%, and the non-notched strength and elongation at break achieve maximum when the addition amount of POE-g-MAH was 7%.4. Using POE-g-MAH as compatibilizer, the flame retardant synergistic effect of the modificated nano zinc borate and APP/PER for the PP composites has been investigated. The result shows that TEA could significantly improve the surface performance of nano ZB and efficiently prevent the reunion of nano particles, which make these particles dispersity to be well in the matrix. The compatibility between PP and Nano zinc borate not only obviously increase the flame retardant properties of composite, but also maintain its good mechanical properties. When the ZB addition amount was 3%, the LOI was maximum, and the carbon residue was about 24 percent, which is more than 208% that of the IFR composite without ZB. The tensile strength, flexural strength, flexural modulus and impact strength, elongation at break were almost not changed, which displayed that the synergistic effect of nano zinc borate and APP/PER was good.
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