Preparation And Properties Of Phosphorus-doped Intrinsic Flame Retardant Polyurethane

In this thesis, two different kinds of microcapsules with anti-friction and anti-wear properties were prepared by seed suspension method The morphology, chemical structure, thermal storage properties, hydrophobicity, and hardness of the microcapsules were studied by SEM、FT-IR、DSC、CA and DSI tests. The as-prepared microcapsules were added into the epoxy matrix to form the epoxy/microcapsule composites and the tribological properties of the composites were evaluated. The detailed results are listed as follows:Through seed suspension method combining with interfacial precipitation or sol-gel methods, two kinds of microcapsules with polyethylene wax(PE-WAX) as the core material and calcium carbonate or silica as the shell material were prepared and the influences of preparation process on the properties of PE-WAX emulsion, morphology and properties of the microcapsules were studied. The results showed that : by adopting Span 80 and Tween 80 as the emulsifier, concentration of the emulsifier is 2% relative to the core material and emulsifying speed is 7000r/min, the PE-WAX spheres from the emulsion has the best morphology and has uniform size distribution. Microcapsules encapsulated by Calcium carbonate and silica were prepared using these PE-WAX spheres as raw materials. SEM results showed that: the microcapsules with the two kinds of inorganic shell materials have good morphology and narrow size distribution. Combining with the TGA and HF corrosion results-the real value of the core/shell ratio is very close to the theoretical value of the core/shell ratio, microcapsules with two kinds of inorganic shell were successfully prepared. Comparing with the pure PE-WAXspheres, the phase change temperature of the microcapsules increased by 3-7℃ by DSC. Meanwhile, the decomposition temperature increased obviously due to the thermal hindrance of the inorganic shell.Epoxy/microcapsule composites were prepared by adopting epoxy as the matrix and two kinds of PE was microcapsules as the filler. CA tests demonstrated that the composites exhibited hydrophobic properties with the addition of the microcapsules. The influence of the microcapsule addition on the tribological properties of the composites was discussed and the results showed that the friction coefficient and anti-wear properties of the composites are much better than the pure epoxy due to the collapse of the microcapsule and the leakage of the lubricating filler arised from the shearing force of the friction during the frictional process, which could not only broaden the application field of the microcapsules, but also provide scientific guidance to the design and preparation of the novel high performance self-lubricating polymer materials.