交联聚甲基丙烯酸甲酯/复合芯材相变纳米胶囊的制备与性能

Preparation and property of nanoencapsulated binary phase change materials with crosslinked poly(methyl methacrylate)

采用无皂乳液聚合法制备以正十八烷和硬脂酸丁酯复合相变材料为芯材、聚甲基丙烯酸甲酯为壁材的相变纳米胶囊.分别引入季戊四醇三丙烯酸酯(PETA)和N,N′-亚甲基双丙烯酰胺(BIS)对壁材聚合物进行交联改性,透射电镜(TEM)结果表明,PETA交联的纳米胶囊形貌更为规整,分散性和成囊性较好.然后,用示差扫描量热仪(DSC)和热重分析仪(TGA)对PETA交联的纳米胶囊和未交联的纳米胶囊进行储热性能和耐热性能分析表明,交联剂的引入增大了复合相变材料和壁材聚合物的起始失重温度,稳定性得到提高,且交联剂赋予聚合物的致密交联网络阻缓了芯材的逸出,相变焓升高.

Nanoencapsulated phase change materials with n-octadecane and n-butyl stearate as binary coresandcrosslinkedpoly(methyl methacrylate)as shell were prepared through surfactant-free emulsion polymerization.Pentaerythritol triacrylate(PETA)and N,N'-methylene bisacrylamide(BIS)were used as crosslinking agents to modify the shell polymer,respectively.The results of transmission electron microscopy(TEM)showed that the morphology of nanocapsules with PETA as crosslinking agent was more regular and had better dispersive and cystic properties,compared with BIS as crosslinking agent.Then,the thermal storage and heat resistance properties of PETA crosslinked nanocapsules and uncrosslinked nanocapsules were analyzed by differential scanning calorimeter(DSC)and thermogravimetric analyzer(TGA),showing that the introduction of crosslinking agent can effectively improve the stability of nanocapsules based on the increase of initial weight loss temperature of the binary phase change materials and shell polymer,and the dense crosslinking network endowed by crosslinking agent can slow down the escape of core material and thus increase the phase change enthalpy.