Study On The Prepartion And Properties Of Nonionic Polyurethane And Its Phase Change Nanocapsules

In recent years, as the exacerbating of energy crisis, people pay more and more attention to phase-change energy storage as one of efficient ways of storing energy. MEPCM can storage a great of latent heat, which made it have temperature regulating function so that it has great application potentiality in lots of fields. How to package solid-liquid phase change material is the key factor for its commercial application.A series of phase changed materials nanocapsules (PCMN) with paraffin as core materials and nonionic polyurethane as emulsifier and shell materials were prepared without any additional emulsifiers. The PCMNs were able to be stably dispersed in water. The particle size, morphology, thermal stability and phase change properties were characterized by Dynamic Light Scattering (DLS), TEM, DSC and TGA. The PCMN with cross-linked shell had two kinds of particle structures under transmission electron microscope: core-shell structure and polyurethane particle. PCMNs with different phase change enthalpy were obtained by adjusting the mass ratio of core to shell. The phase change enthalpy of PCMN was able to reach 89 J/g. It was indicated by the thermo gravimetric analysis that the thermal stability of PCMN became better with the increase of the cross-linker content.A series of phase changed materials nanocapsules (PCMN) with octadecane as core materials and nonionic polyurethane as emulsifier and shell materials were prepared. The particle size, morphology, thermal stability, phase change properties, redispersibility, freeze-thaw stability and mechanical stability of PCMN suspension were studied.