Preparation Of Composite Materials Modified By Inorganic Flame Retardant And Nonspherical Composite Particles

Polymer materials are widely used in industry, agriculture, national defense and daily life, however, there are some intrinsic drawbacks for polymer materials, such as low strength, poor heat resistance and easy flammability. Through the combination of inorganic materials(usually inorganic particles) and polymer materials, high-performance composite materials can be obtained. In this paper, the effects of modified ammonium polyphosphate on the properties of unsaturated polyester resin were studied, as well as nonspherical polystyrene particles were prepared by using montmorillonite as modifier through suspension polymerization.Silica coating was first formed on the surface of inorganic ammonium polyphosphate(APP) particles by using tetraethoxysilane(TEOS), ammonia solution, ethanol, water as basic materials through sol- gel process. Then silane coupling agent KH570 was used to modify the SiO2 layer formed on the surface of APP particles. Finally, the inorganic and organic hybrid modified ammonium polyphosphate(MAPP) was prepared. The chemical structures and surface morphologies of APP and MAPP were characterized by FTIR and SEM, the physical properties of APP and MAPP were investigated by water solubility test, WCA, TG. Compared with APP, the water solubility of MAPP was greatly decreased, the hydrophobicity and temperature stability were enhanced. UPR composites were prepared after the heat curing of ammonium polyphosphate/UPR mixture. The properties of the composites were analyzed by SEM, universal testing machine, TG. In comparison with APP/UPR, the cohesive force between MAPP and UPR was improved, the tensile strength and impact strength of the composites were increased, the heat stability and flame retardancy were also enhanced. When the content of MAPP was 30%, LOI of MAPP/UPR could reach 28.5%.Lamelliform organic montmorillonite(OMMT) was also obtained by using CTAB as modifier though ion exchange process. Nonspherical polystyrene particles were prepared by introducing OMMT in suspension polymerization of styrene. The influence of OMMT content, water-oil rate and dispersing agent dosage on the particle morphology were investigated. In the presence of OMMT, kinds of nonspherical particles were prepared. The formation mechanism of the nonspherical particles was discussed. By using the same method, nonspherical PMMA/OMMT particles were also prepared.