Papers by Author: Shan Hu

Abstract: The melamine phosphate (MP) was synthesized from melamine and phosphate acid. Aluminum oxide (Al2O3) was added into the MP during its synthesis. Fourier transform infrared spectroscopy (FTIR) was used to characterize the reaction products. The composites were prepared from polypropylene (PP) and intumescent flame retardant (IFR) additives of MP and pentaerythritol (PER). The effect of Al2O3 content on the properties of the composites was investigated by the limiting oxygen index (LOI), thermogravimetry (TG) and scanning electron microscopy (SEM). The results indicated that the LOI value of the composites could be enhanced obviously with suitable content of Al2O3. When the Al2O3 content was 6 wt% in MP, the LOI value increased to 35.5% from 31.0% for the composite without Al2O3, the amount of residual char at 600°C increased from 8.9 wt% to 13.9 wt%.

Abstract: The grafted starch was prepared from corn starch and maleic anhydride. Fourier transform infrared spectroscopy (FTIR) was used to characterize the product. The Poly(lactic acid) (PLA)/grafted starch composites were prepared by means of a melt blending method. The effect of grafted starch content on the properties of the composites was investigated. The morphology of the composites was observed by scanning electron microscopy (SEM). Thermal degradation properties were studied by thermogravimetry (TG). The results indicated that the toughness could be improved obviously by adding suitable content of grafted starch. When 35 wt% grafted starch was added into PLA, the tensile strength decreased to 26.6 MPa from 51.7 MPa for pure PLA, elongation increased from 12.0% to 20.3%, flexural strength decreased from 99.0 MPa to 50.2 MPa, impact strength increased from 4.20 kJ/m² to 6.28 kJ/m².

Abstract: The melamine phosphate (MP) was synthesized from melamine and phosphate acid. Zinc oxide (ZnO) was used as a synergistic agent by adding into the MP during the synthesis process. The reaction products were characterized by Fourier transform infrared spectroscopy (FTIR). The properties of polypropylene (PP) composites containing intumescent flame retardant (IFR) additives of melamine phosphate and pentaerythritol (PER) were investigated by the limiting oxygen index (LOI), UL-94 vertical burning test, thermogravimetric analysis (TG) and scanning electron microscopy (SEM). The results indicated that the LOI value of the composites could be enhanced obviously with suitable content of ZnO. When the ZnO content was 6 wt% in MP, the LOI value reached 34.1%, which showed 10% higher than that of the composites without ZnO.

Abstract: The graphite-modified PZN-PZT/PVDF composites were fabricated by hot-pressed process using PZN-PZT ceramic powder, PVDF and graphite powder. The effect of graphite content on the electrical properties of the piezoelectric composites was investigated. The results indicated that the piezoelectric constant d33 could be enhanced obviously by adding suitable content of graphite into the composites. When 0.8wt% graphite was added, the PZN-PZT/PVDF composites showed the excellent properties: σ=3.31×10-6S/m, εr=133, tanδ=0.066, Kp=0.228, Qm=22.8 and d33=40.6pC/N, which showed 28% higher than that of the composites without graphite.