聚乙二醇/乙基纤维素复合相变蓄热材料的制备及性能

Preparation and characterization of polyethylene glycol/ethyl cellulose composite phase change thermal energy storage material

以聚乙二醇(PEG)为功能材料、乙基纤维素(EC)为支撑材料,根据有机相分离法制备了聚乙二醇/乙基纤维素(PEG/EC)复合相变材料,其中PEG的含量最大可达84.6%(质量分数)。采用扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FT-IR)、差示扫描量热仪(DSC)、热重分析仪(TG)等技术考察了PEG/EC复合相变蓄热材料的微观形貌、相容性及化学结构、蓄热性能及稳定性。结果表明,PEG/EC复合相变材料为不规则颗粒状粉末,PEG与EC的相容性较好,分子间形成氢键而没有形成新的化学键。由于EC与PEG间形成的氢键及分子链缠绕等作用,使PEG/EC复合材料呈网络结构,使得PEG发生固-液相变时失去了流动性。PEG/EC复合材料作为固-固相变材料,最大相变焓可达151.8J/g,在温度低于80℃范围发生相变,稳定性可靠。

This paper deals with the preparation,characterization,and determination thermal energy storage properties of polyethylene glycol/ethyl cellulose （PEG/EC）composite as solid-solid composite phase change materials （PCMs）.The composite PCMs were prepared by blending PEG and EC in the light of the organic phase separation method.And the maximum mass fraction of PEG in the composite was 84.6%.The composite PCMs were characterized by FT-IR,SEM,DSC and TG analysis techniques to study the morphology,compati-bility,structure and thermal properties of PEG/EC composites respectively.The results show that PEG/EC composite PCMs were irregular granules which have good compatibility not due to new chemical bond but hy-drogen bond formed between PEG and EC molecules.PEG/EC composite was changed into network structure and PEG loses its mobility when temperature was higher than its melting point on account of hydrogen bond and winding among PEG and EC molecules,etc.So the composites turn into solid-solid PCMs,which have good thermal stability when phase change occurs under 80 ℃,and maximum enthalpy may reach 1 5 1 .8 J/g.