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Mmonium polyphosphate (APP), tris (clorisopropyl) phosphate (TCPP), melamine cyanurate (MCA), expandable graphite (EG) and the mixture of APP and EG were added to rigid polyurethane foams (RPUF) respectively. The relationships between limiting oxygen index (LOI), fire resistance time, heat release rate (HRR) and heat of combustion (HoC) for the flame retardant RPUF were studied by oxygen bomb calorimeter, oxygen index test, fire resistance time test and cone calorimeter. Chemical states of phosphorus atom on the surface of the residues after HoC test were characterized by X-ray photoelectron spectroscopy (XPS). The results show that the sequence for HoC is as follow: RPUF/APP, RPUF/EG/APP, RPUF/TCPP, RPUF/ MCA, RPUF/EG, RPUF/EG/APP system has the highest LOI, better char residue blocking effect, lower HRR and mass loss, modest smoke production. The percentage of phosphorus pentoxide in RPUF/APP (57.9%) is higher than RPUF/EG/APP system (35.9%). HoC of flame retardant RPUF not only mainly relates to the composition of system and the contribution of flame retardants but also relates to the interaction between the components; the values of LOI, char residue blocking effect, HRR and smoke production mainly depend on the flame retardant mechanism. [ABSTRACT FROM AUTHOR]

To prepare nano-size ZnO, the zinc acetate and lithium hydroxide was used as raw material and ethanol as the solvent. The sol-gel method supplemented with microwave radiation was adopted. The samples were characterized by powder X-ray diffraction, UV-Vis spectroscopy, energy dispersive X-ray spectrum and electron microscopy. Under the condition of different microwave radiating times, the photocatalytic performance of prepared ZnO samples was studied using UV light as illumination device and XB-R as stimulant pollutant. The characterization and catalytic activities of ZnO prepared with microwave method are compared with that of one prepared using traditional sol-gel method. The results indicate that microwave synthesized ZnO has a smaller particle size and better photocatalytic activity than traditionally prepared ZnO. Sample with 30 minutes microwave radiation has the best performance. Its degradation ratio could reach 90 percent when 100 mL XB-R with the density 20 mg/L and 10 mg nano size ZnO is irradiated under UV light for 40 minutes. [ABSTRACT FROM AUTHOR]

Ammonium polyphosphate (APP) was modified by aminosilane coupling agents. Modified ammonium polyphosphate was characterized by water solubility test, X-ray photoelectron spectroscopy(XPS) and thermogravimetric analysis(TGA). The results showed that modified ammonium polyphosphate has good hydrophobicity; a new bond was formed between aminosilane coupling agents and APP; the rate of thermal weight loss of modified ammonium polyphosphate decreased significantly. Limiting oxygen index (LOI) and mechanical property tests showed that the flame retardant and mechanical properties of the intumescent flame retardant PP with modified ammonium polyphosphate and dipentaerythritol (DPER) were improved apparently. The method of surface modificated APP by aminosilane coupling agents is not only simple and environmental friendly, but also decreases water solubility of APP and improves the flame retardancy and interface compatibility of the intumescent flame-retardant PP. [ABSTRACT FROM AUTHOR]