聚乙二醇基定形相变储热材料的制备、表征及热性能研究

发布时间：2018-05-15 09:34

  本文选题：聚乙二醇 + 定形相变材料　； 参考：《北京建筑大学》2017年硕士论文

【摘要】：随着能源危机愈演愈烈,人们致力于开发替代能源和新的储能技术。相变储能材料利用材料的相变潜热进行能量的储存和释放,控制周围环境温度的同时达到节约能源的目的,能够解决能源在空间和时间上的不匹配问题,因此成为大家关注的热点。其中,定形复合相变储能材料具有固-液相变储能材料和固-固相变储能材料的双重优点,成为最具潜力的储能材料之一。本文以聚乙二醇(PEG)为相变材料,选择泡沫碳、硅藻土和蒙脱土作基体材料,采用物理共混法制备多个系列的聚乙二醇基定形相变储热材料。利用扫描电镜(SEM)、X射线衍射(XRD)、N2吸附(BET)、红外光谱(FTIR)对纯PEG、基体材料以及定形复合相变材料进行表征,通过差示扫描量热(DSC)、热重分析(TGA)对聚乙二醇基定形复合相变材料的热性能进行研究。研究结果表明,聚乙二醇/泡沫碳定形相变储热材料的定形能力为90wt%,而聚乙二醇/硅藻土和聚乙二醇/蒙脱土复合相变材料的定形能力分别为55wt%和60wt%,聚乙二醇与基体材料之间只存在简单的物理作用。聚乙二醇/泡沫碳复合相变材料的相变温度随聚乙二醇分子量的增加而增大,相变焓随聚乙二醇分子量的增大先增后减,PEG分子量为4000的PEG/泡沫碳复合相变材料的熔化焓最大(168.5 J·g~（-1）);PEG4000/泡沫碳复合相变材料的相变温度和相变焓随PEG4000质量分数的增加而增大。55wt%PEG/硅藻土复合相变材料的凝固焓和熔化焓分别为76.93 J·g~（-1）和80.50 J·g~（-1）,凝固点和熔点分别为27.1℃和51.5℃,较纯PEG的相变温度变化很小(0.3℃和0.4℃)。60wt%PEG/蒙脱土复合相变材料的熔化焓为95.1 J·g~（-1）,聚乙二醇/蒙脱土复合相变材料的相变温度与相变焓均随PEG质量分数的增加而有所增大,但相变温度低于聚乙二醇的。聚乙二醇基复合相变材料具有良好的热循环性和热稳定性,经200次热循环后样品仍能保持定形,相变温度和相变焓基本不变,200℃以下样品均无热分解。
[Abstract]:As the energy crisis intensifies, people are devoting themselves to developing alternative energy sources and new energy storage technologies. Phase change energy storage materials use the latent heat of the materials to store and release energy, control the ambient temperature and achieve the goal of energy conservation, which can solve the problem of energy mismatch in space and time. Therefore becomes the hot spot which everybody pays attention to. Among them, the amorphous composite phase change energy storage material has the dual advantages of solid-liquid phase change energy storage material and solid-solid phase change energy storage material, so it has become one of the most potential energy storage materials. In this paper, polyethylene glycol (PEG) was used as phase change material, foam carbon, diatomite and montmorillonite were selected as matrix materials, and several series of polyethylene glycol based amorphous phase change thermal storage materials were prepared by physical blending method. The pure PEG, matrix materials and amorphous composite phase change materials were characterized by scanning electron microscopy (SEM), X ray diffraction (XRD) and X ray diffraction (XRD). The thermal properties of polyethylene glycol based composite phase change materials were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results show that The setting ability of polyethylene glycol / carbon foam phase change thermal storage material is 90 wt, while that of polyethylene glycol / diatomite and polyethylene glycol / montmorillonite composite phase change material is 55 t% and 60 wt respectively. There are simple physical effects. The phase transition temperature of polyethylene glycol / foamed carbon composite phase change material increases with the increase of molecular weight of polyethylene glycol. The maximum enthalpy of melting of PEG/ foam carbon composite phase change materials with PEG molecular weight of 4000 increases and then decreases with the increase of molecular weight of polyethylene glycol. The maximum enthalpy of melting of PEG4000 / PEG4000 / PEG4000 / carbon foam composite PCMs increases with the increase of PEG4000 mass fraction. The solidification enthalpy and melting enthalpy of PEG / diatomite composite phase change material were 76.93 J / g ~ (-1) and 80.50 J / g ~ (-1) respectively, the solidification point and melting point were 27.1 鈩，

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