采用界面聚合的方法,以甲苯-2,4-二异氰酸酯(TDI)和乙二胺(EDA)为反应单体,非离子表面活性剂聚乙二醇壬基苯基醚(OP)为乳化剂,合成了正二十烷为相变材料的聚脲包覆微胶囊.结果表明,二异氰酸酯和乙二胺按质量比1.9∶1进行反应.以透射电镜和激光粒度分析仪分析微胶囊,测得空心微胶囊直径约为0.2μm,含正二十烷微胶囊约为2-6 μm.红外光谱分析证明,壁材料聚脲是由TDI及EDA两种单体形成的.正二十烷的包裹效率约为75%.微胶囊的熔点接近囊芯二十烷的熔点,而其储热量在壁材固定时随囊芯的量而变.热重分析表明,囊芯正二十烷、含正二十烷的微胶囊以及壁材料聚脲,能够耐受的温度分别约为130℃、170℃及270℃%For heat energy storage application, polyurea microcapsules containing phase change material, n-eicosane, were synthesized by interfacial polymerization method with toluene-2,4-diisocyanate (TDI) and ethylene diamine (EDA) as monomers in an emulsion system. Poly (ethylene glycol) octyl-phenyl ether (OP), a nonionic surfactant,was the emulsifier for the system. The experiments indicated that TDI was reacted with EDA in a mass ratio of 1.9 to 1.The sizes of microcapsules were analyzed with TEM and laser particle analyzer, which showed the empty microcapsules were about 0.2 μm and those containing n-eicosane were 2-6 μm. FTIR spectra proved the formation of wall material, polyurea, from the two monomers, TDI and EDA. Encapsulation efficiency of n-eicosane was about 75%. Microcapsules of n-eicosane melted at a temperature close to that of n-eicosane, while its stored heat energy varied with the amount of core material n-eicosane. Thermogravimetric analysis revealed that the core material n-eicosane, micro-n-eicosane, and wall material polyurea could withstand temperatures up to 130 ℃, 170 ℃, and 270 ℃,respectively.
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