纳米SiO2改性石蜡相变微胶囊涂料的制备及性能表征

Preparation and Characterization of Nano SiO2 Modified Paraffin Phase Change Microcapsule-Based Coatings

相变微胶囊在能源节约方面可以起到重要作用。以石蜡为芯材,三聚氰胺树脂为壳材,并使用纳米SiO2作为改性剂,采用原位聚合法制备相变微胶囊。研究了纳米SiO2用量对微胶囊性能的影响。通过差示扫描量热仪(DSC)、扫描电子显微镜(SEM)以及同步热分析仪(TGA)等对相变微胶囊的相变特性、表面形貌、热稳定性以及包裹率等进行了测试表征。结果表明:纳米SiO2用量为5%的改性相变微胶囊有最大的相变潜热和包裹率,分别为145. 7 kJ/kg和81. 8%,微胶囊的相变温度为29. 1℃,粒径约60μm。将改性相变微胶囊作为添加剂加入涂料中,随着添加量的增加,复合涂料的储放热性能依次增强。相变微胶囊用量为30%的复合涂料与未添加微胶囊的涂料相比较,当温度从15℃左右升温至31℃所需时间增加了12 min左右,温度从38℃左右降温至20℃所需时间增加了6 min左右。

Phase change microcapsules can play an important role in energy conservation.The phase change microcapsules were prepared by in-situ polymerization with paraffin as the core material and melamine resin as the shell material and nano-SiO2 as the modifier. The effects of different amount of nano-SiO2 on the performance of microcapsules were studied.The phase change characteristics,surface morphology,thermal stability and encapsulation rate of phase-change microcapsules were characterized by differential scanning calorimeter(DSC),scanning electron microscope(SEM)and synchronous thermal gravimetric analyzer(TGA).The results showed that the phase change microcapsules modified with nano-SiO2 at 5% indicated the highest phase change latent heat and encapsulated rate,which were 145. 7 kJ/kg and 81. 8%,respectively. The phase change temperature of the microcapsules was 29. 1 ℃,and the particle size was about 60 μm. When the nano SiO2 modified phase change microcapsule was added to the coatings as an additive,and the heat storage and release properties of the composite coatings were successively enhanced with the increase of the added amount. The composite coatings with phase change microcapsule mass fraction of 30%increased the time needed for temperature rising from 15 ℃ to 31 ℃ by about 12 min,and the time needed for temperature dropping from 38 ℃ to 20 ℃ by about 6 min,compared with the coatings without microcapsule.