Preparation And Characterizations Of A Flexible Phase Change Material Of PEG And PU With Porous Membrane Structure

In this paper, PEG was selected as phase change material. In order to control transition point accurately, DSC tests were performed to investigate the relationship between the molecular weight, matching ratio, components and transition point, transition enthalpy. Based on the analysis, the perfect PEG binary systems were selected. The results indicated:The melting enthalpy(100～200J/g), melting temperature(10～80℃)and others properties of PEG depended on the molecular weight much and there was a positive increasing relationship between them, theoretically pure PEG of different molecular weight can satisfied with practical demands, but it is hard to produce the material . However the blend of PEG with different molecular weights can solve these problems which pure PEG encountered, and achieve better properties. Especially when blended PEG of different molecular with appropriate ratio, work material suitable for self-adaptable phase change fabrics can be acquired, which transition temperature is about 30～60℃and transition enthalpy is about 150～190J/g. By the analysis of phase change of PEG1000/2000 binary system, the better matching mixture will be obtained.Subsequently, PEG binary systems selected were blended with liquid PU to prepare the porous membrane PCM. After a series of characterizations and testing, the properties and characteristic of porous membrane PCM were investigated. The result showed there was no new chemical bonds appearing after the blending of PEG and PU, and PEG kept same crystallization structure. Further more, porous membrane PCM had suitable transition temperature(40～55℃) and high transition enthalpy(129.1J/g). In addition, the moisture permeability changed abruptly during transition, which had self-adjusted ability and cooperated with thermal adjusting.It meant that porous membrane PCM can be regarded as functional fabrics. This method can improve the flexibility of porous PCM and solved the problem of low content of working materials problem in fabrics; can also cooperated with thermal adjusting and moisture adjusting, it succeed in introducing the porous technical into the fields of functional fabric's formation, and developed a new way to improve the phase change enthalpy largely for adjustable fabrics.