摘要：以质量比为3∶7的固体石蜡与液体石蜡均匀混合得到复合石蜡,甲苯-2,4-二异氰酸酯(TDI)单体和乙二胺(EDA)在乳化剂辛基酚聚氧乙烯醚的乳化作用下,通过界面聚合包覆在芯材复合石蜡的表面形成石蜡-聚脲相变微胶囊,对比差热曲线和加热-冷却曲线表征芯材复合石蜡的蓄热性能,探讨EDA与TDI质量比对聚脲囊壁产量的影响,以及核壳质量比对石蜡-聚脲相变微胶囊粒径、包覆效率以及蓄热性能的影响。结果表明:加热-冷却曲线与差示扫描量热曲线显示复合石蜡的熔点接近;聚脲囊壁的产量随着水合EDA与TDI质量比的增大近似线性增大,质量比达到 0.5∶1.0后,聚脲囊壁的产量不再增大;核壳质量比为 2.0∶1.0时制得石蜡-聚脲相变微胶囊的熔点为28.1℃,相变焓为58.4 kJ/kg,包覆效率为87.5%,粒径约为4.32μm,粒径分布均匀。

关键词：核壳结构；石蜡；微胶囊；聚脲；相变；蓄热性能

Abstract： Composite paraffin was prepared by evenly mixed solid paraffin and liquid paraffin with mass ratio of 3∶7. The paraffin-polyurea phase change microencapsules were formed by the method of interfacial polymerization using 2, 4-toluene diisocyanate (TDI) and ethylenediamine (EDA) as monomers, octyl phenol ethoxylates (OP-10) as an emulsifier. DSC curve and heating-cooling curves characterizing energy-storage performance of the composite paraffin were compared. The effect of EDA and TDI mass ratio on the polyurea shell yield was explored. The effect of core-shell mass ratio on particle size, coating efficiency and energy-storage performance of the parraffin-polyurea phase change microencapsules was investigated. The results show that the melting point measured by heating-cooling curves is close to that of DSC curve. The polyurea shell yield approximately linearly increases with the increase of mass ratio of hydrated EDA and TDI. The yield keeps constant until the mass ratio reaches 0.5 ∶1.0. When the core -shell mass ratio is 2.0 ∶1.0, the melting point of the paraffin-polyurea phase change microencapsules is 28.1 ℃, the enthalpy is 58.4 kJ/kg, the coating efficiency is 87.5% , the average particle size is about 4.32 μm, and the particle size distribution is uniform. 

Keywords: core -shell structure; paraffin; microcapsule; polyurea; phase change; energy-storage performance