纳米胶囊化二元复合相变材料的制备及热性能

以正十八烷(C18)和硬脂酸丁酯(BS)为复合芯材(PCMs),聚甲基丙烯酸甲酯(PMMA)为壁材,通过无皂乳液聚合法制备纳米胶囊化相变材料,探讨了乳化剂种类和用量、引发剂种类和用量、芯壁比对纳米胶囊的影响,并采用TEM、SEM、FTIR、XRD、DSC和TGA对纳米胶囊的形貌、化学结构和热性能进行了测试表征。结果表明:当烷基乙烯基磺酸盐(AVS)用量占油相总质量的3.0%,过硫酸铵(APS)用量占单体MMA质量的1.2%,芯材与壁材质量比(芯壁比)为2∶4时,制备的纳米胶囊单体转化率最高、粒径最小、球形形貌最规整。相变纳米胶囊的熔融焓和结晶焓分别为56.89和54.02 J/g,具有良好的储热能力和耐热性能,且整理于棉织物上有较好的调温效果。

Preparation and Thermal Properties of Nanoencapsulated Binary Phase Change Materials

Nanoencapsulated phase change materials were prepared through surfactant-free emulsion polymerization with n-octadecane (C18) and n-butyl stearate (BS) as binary cores and poly(methyl methacrylate) (PMMA) as shell. The effects of the type and dosage of emulsifier, the type and dosage of initiator and core/shell mass ratio on nanocapsules were studied. The surface morphology, chemical structure and thermal properties of phase change nanocapsules were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). The results indicate that the best preparation conditions of nanocapsules are when the alkyl vinyl sulfonate (AVS) dosage is 3.0wt% to oil phase, ammonium persulfate (APS) dosage is 1.2wt% to MMA and core/shell mass ratio is 2:4. At the moment the monomer conversion of nanocapsules is the highest, particle size is the smallest and spherical morphology is the most regular. In addition, phase change nanocapsules have good latent heat storage capacity and heat resistance, and their melting enthalpy and crystallization enthalpy are 56.89 J/g and 54.02 J/g, respectively. The finished fabrics with phase change nanocapsules have better thermoregulation effect.