Synthesis and Characterization of Poly(acrylonitrile-co-itaconate) - graft-Poly(ethylene glycol) Copolymers as Novel Solid-Solid Phase Change Materials for Thermal Energy Storage

The core of this study firstly synthesizes an "active" matrix materials with the itaconic acid containing double-carboxyl end group and acrylonitrile copolymer through molecular design. Then, the poly(ethylene glycol)(PEG) was grafted to the poly(acrylonitrile-co-itaconate)[P(AN-co-IA)] using methylenediphenyl diisocyanate(MDI) as a bridge-base and cross-linking agent. The poly(acrylonitrile-co-itaconate)-graft-poly(ethylene glycol)[P(AN-co-IA)-g-PEG] solid-solid phase change materials(SSPCMs) were obtained in this paper. Furthermore, the chemical structure, crystallization properties, thermal energy storage properties, crystallization process, thermal stabilities, and hydrophilic property of the SSPCMs were investigated using Fourier transform infrared, differential scanning calorimetry, wide-angle X-ray diffraction, polarized optical microscopy, thermogravimetric analysis and water contact angle, respectively. The results showed that these SSPCMs had the characteristics of solid-solid phase change, excellent energy storage properties and latent heat of 70 J/g or more. The crystalline morphology and crystal structures of the synthesized SSPCMs are difference from PEG and P(AN-co-IA). Moreover, The SSPCMs have a good thermal stability and the initial decomposition temperature(T-d) is 289 degrees C, and the hydrophilic property of the blend membrane were improved, the water contact angle minimum can be achieved at 33. 71 degrees C.