硬脂酸-月桂酸二元复合相变材料

Binary multiple stearic acid/lauric acid phase change material

以硬脂酸(SA)、月桂酸(LA)为原料,通过熔融共混法制备了二元脂肪酸相变材料。采用红外光谱(FTIR)、偏光显微镜(POM)、差示扫描量热仪(DSC)及温度记录仪分别表征了共混相变材料的结构、结晶形态、相变温度和焓值以及保温性能。FTIR表明共混相变材料中硬脂酸与月桂酸通过分子间作用力结合在一起;POM表明SA与LA在共混物中形成共晶结构,且随SA/LA质量配比的减小,结晶半径减小;DSC表明共混相变材料的结晶焓达到200J/g,随SA/LA质量配比的减小结晶温度先降低后升高,表现出低共熔物特征;步冷曲线表明,随SA/LA质量配比的减小,平台温度先降低后升高,且当SA/LA质量比为1/2时,温度平台为30.9℃,保温时间为25min,约为纯硬脂酸或月桂酸保温时间的2倍。

With stearic acid(SA),lauric acid(LA) as raw materials,the binary of fatty acids phase change materials were prepared by melt blending.Phase change temperature and latent heat of the SA/SA PCM were characterized using differential scanning calorimetry(DSC).The structure,crystalline morphology,and thermal insulation properties of the SA/LA PCM were investigated using fourier transformation infrared spectroscope(FTIR),polarizing optical microscopy(POM),and temperature-recording instrument.The FTIR and POM results showed that SA and LA was combininged by intermolecular forces,and SA/LA PCM was formed eutectic structure,moreover,the radius of crystal reduced with decrement of the SA/LA ratio.The DSC results indicated that SA/LA PCM had high latent heat storage capacity of more than 200 J/g.With the reducing SA/LA ratio,crystallization temperature reduced first and then increased,showing the performance characteristics of eutectic mixture.Cooling curves of SA/LA PCM showed that with the reducing SA/LA ratio,the platform temperature reduced first and then increased,and when the SA/LA was equal to 1/2,the temperature platform appeared at 30.9 ℃,the soaking time was continued for about 25 min twice as long as that of pure SA or LA.