氮化硼/脂肪酸复合相变材料的形状稳定性和导热性分析

Shape Stability and Thermal Conductivity of Boron Nitride/FattyAcid Phase Change Composites

中文关键词: 氮化硼  脂肪酸  成型复合相变材料  泄漏率  热导率

英文关键词: boron nitride  fatty acid  shape-stabilized phase change composites  leakage rate  thermal conductivity

中文摘要:

      目的 探究氮化硼(BN)对月桂酸(LA)、肉豆蔻酸(MA)、棕榈酸(PA)和硬脂酸(SA)等4种脂肪酸(FA)的形状稳定性和导热性的影响。方法 将FA融化后，添加BN，在熔融状态下共混，制备出4种不同的成型复合相变材料，并分析BN的添加量、光−热转换、储热时间和温度对复合相变材料的密度和形状稳定性的影响，以及BN添加量对FA相变材料热导率的影响。结果 复合相变材料的密度随着BN添加量的增加呈线性增大趋势，稳定性也随之增强，在4种FA中添加BN的最佳质量分数分别为68%、69%、69%、68%;复合相变材料的泄漏率随着储热时间的增加呈线性增大趋势，在储热12 h时其泄漏率小于0.6%，泄漏率随着储热温度的升高而增大，在高于熔点25 ℃左右条件下加热3 h，泄漏率低于0.1%;材料经过4次光−热转换后，其泄漏率小于0.4 %;复合材料的热导率分别比纯FA的热导率提高了401.91%、597.92%、353.74%、304.95%。结论 制备的成型复合相变材料具有不同的储能温度、导热性能和稳定性，可以作为运输过程中的保温材料。

英文摘要:

      The work aims to explore the effects of boron nitride (BN) on the shape stability and thermal conductivity of lauric acid (LA), myristic acid (MA), palmitic acid (PA) and stearic acid (SA). Four different molding phase change composites were prepared by blending FA with BN after melting. The effects of BN addition, photothermal conversion, heat storage time and temperature on the density and shape stability of phase change composites, as well as the effects of BN addition on the thermal conductivity of FA phase change materials were analyzed. The results showed that the density of phase change composites increased linearly with the increase of BN content, and its stability also increased. The optimal mass fractions of BN added in the four FAs were 68%, 69%, 69% and 68%, respectively. The leakage rate of phase change composites increased linearly with the increase of heat storage time. The leakage rate was less than 0.6% after 12 h of heat storage. The leakage rate increased with the increase of heat storage temperature, and the leakage rate was less than 0.1% after heating for 3 h above the melting point of 25 °C. After four photothermal conversions, the leakage rate was less than 0.4%; the thermal conductivity of the composites was 401.91%, 597.92%, 353.74% and 304.95% higher than that of pure FA, respectively. The prepared phase change composites have different energy storage temperature, thermal conductivity and stability, which can be used as insulation materials during transportation.