25^(#)相变蜡-十四醇相变共晶材料的制备及性质研究

Preparation and properties of 25^(#)phase changewax-tetradecyl alcohol phase change eutectic material

为了解决单一相变材料热工性质的不足,以25#相变蜡-十四醇相变共晶材料(PCEM)为芯材,三聚氰胺改性脲醛树脂(MUF)和三聚氰胺改性酚醛树脂(MPF)为壁材,通过原位聚合法制备了相变微胶囊,探讨了壁材种类、乳化剂用量及乳化转速对微胶囊的影响,并采用SEM、DSC、FT-IR、TG对微胶囊的微观结构、热学性质及稳定性进行测试分析。结果表明,以MUF为壁材,所制备的微胶囊近似球形,粒径分布均匀,其相变温度和相变潜热分别为22.43℃和74.00 J/g,包覆率高达74.88%。芯材与壁材之间仅为简单的物理嵌合,且50次冷热循环后微胶囊的储热性能几乎未发生变化。当温度高于190℃,微胶囊才会出现明显的失重现象,具有良好的储热性能和热稳定性。因此,PCEM在建筑节能领域具有良好的应用前景。

In order to solve the shortcomings of the thermal properties of a single phase change material,the phase change microcapsules are prepared by in situ polymerization with 25#phase change wax-tetradecyl alcohol phase change eutectic material(PCEM)as the core material,and melamine-modified urea-formaldehyde resin(MUF)and melamine-modified phenolic resin(MPF)as the shell material.The effects of shell material type,emulsifier dosage and emulsifying speed on the microcapsules were studied,and the microstructure,thermal properties and thermal stability of phase change microcapsules were tested by SEM,DSC,FT-IR and TG.The results show that when the shell material is MUF,the prepared phase change microcapsules are approximately spherical with uniform particle size distribution.The phase change temperature and phase change latent heat of phase change microcapsules are 22.43℃and 74.00 J/g,respectively,and the coating rate is as high as 74.88%.There is only simple physical fitting between core material and shell material,and the heat storage performance of phase change microcapsules is almost unchanged after 50 cold and hot cycles.Phase change microcapsules have good thermal stability,when the temperature is higher than 190℃,they will show significant weightlessness.Therefore,the PCEM has a good application prospect in the field of building energy efficiency.