Preparation And Properties Of Solid-Solid Phase Change Materials And Fiber

Energy storage by phase change is one of efficient ways of storing thermal energy. The unstable, intermittent energy, such as solar energy, geothermal energy and industrial waste heat, can be used by phase change materials. This paper aimed on the preparation and properties of phase change materials. Phase change materials prepared was used to spinning and the spinning process and phase change property of fiber were primary studied.Firstly, the solid-solid phase change materials were obtained by two-step solution polymerization, using cellulose diacetate (CDA) as matrix materials, the methoxy polyethylene glycol (MPEG) as functional substance. Dibutyltin dilaurate (DBTDL) was used as catalyst to increase the grafting degree of the products. When catalyst’s content was of0.15%, the largest grafting degree of the products prepared with MPEG1000and MPEG1500was obtained. And the grafting degree were of224.03%and189.30%respectively. However, when the amount of catalyst was of0.1%, the grafting degree of MPEG2000reached the largest value of130.0%. Grafting products prepared using different molecular weight MPEG had different phase change temperature and phase transition enthalpy. The solid-solid phase change property was achieved during increasing the temperature.Secondly, the compound of MPEG (MPEG2000and MPEG1500, MPEG1500and MPEG1200, MPEG2000and MPEG1000) was prepared with different mass ratio. The compound was grafted to CDA to prepare solid-solid phase change materials with different phase change temperature and phase transition enthalpy. The phase change property, the crystallization property and thermal property of MPEGs-g-CDA were analyzed by DSC, TG and POM. The results showed that the phase transition temperature of MPEGs-g-CDA prepared with the mixture of MPEG1500and MPEG1200were not been effected by the mass ratio of MPEG1500and MPEG1200. But the phase change temperature of MPEGs-g-CDA prepared with the mixture of MPEG2000and MPEG1000changed from22.3℃to26.7℃with the change of mass ratio of MPEG2000and MPEG1000. The thermal decomposition temperature of phase change materials of MPEGs-g-CDA was about300℃and which was suitable to application requirements.At last, the MPEGs-g-CDA prepared as work substance with different amount and CDA were mixed to prepare phase change fiber by dry spinning. The results showed that the fiber prepared by dry spinning did not reveal transition performance when the content of phase change materials below40%. When the content of MPEGs-g-CDA was of60%, the phase transition enthalpy of fiber was o14.51J/g. And when the content of MPEGs-g-CDA was80%, the phase transition enthalpy of fiber was of47.92J/g.