纤维素基多孔骨架/棕榈酸定形复合相变材料的制备及性能研究

Preparation and property of cellulose-based porous skeletal/palmitic acid shape-stable PCM

有机相变材料低导热性和相变过程中液相物质容易渗漏问题的解决是促进其获得广泛应用的关键。以环氧氯丙烷(ECH)作为交联剂,通过化学交联微晶纤维素(MCC)和氧化多壁碳纳米管(O-MWCNTs)水性共混物的方法制备了一种新型导热多孔骨架,然后利用真空浸渍将棕榈酸(PA)吸附到骨架中,实现了对PA封装的同时增强其导热性。即使在高于PA熔点的温度下被热压,复合相变材料仍可以保持原有形状而无明显泄露,展现出优异的封装性和形状稳定性。当O-MWCNTs的质量分数为4.44%时,复合相变材料的导热系数为0.493W/(K·m),比纯PA增加了128.2%,且此时复合相变材料仍保持157.3J/g的熔融潜热,具有较高的储能密度。

Solving the problems of low thermal conductivity of organic phase change material(PCM)and the easy leakage of liquid phase in the process of phase change are the keys to promote their wide application.A new thermal conductivity porous skeleton was prepared by the method of epichlorohydrin(ECH) chemical crosslinking microcrystalline cellulose(MCC) and oxidized multi-walled carbon nanotubes(O-MWCNTs) water-based blend, and then vacuum impregnation was used to adsorb palmitic acid(PA) into the skeleton to realize the encapsulation of PA and enhance its thermal conductivity at the same time.Even when pressed at a temperature higher than PA melting point, the PCM can still maintain their original shape without obvious leakage, showing excellent encapsulation and shape stability.When the content of O-MWCNTs was only 4.44%,the thermal conductivity of the PCM was 0.493 W/(K·m),which was 128.2% higher than that of pure PA.At this time, the PCM can still maintain the melting latent heat of 157.3 J/g, had higher energy storage density.