Poly(Ethylene Glycol Hexadecyl Vinyl Ether) and its Nanofiber with Poly(Acrylonitrile-covinylidene Chloride)

Abstract

Ethyleneglycol hexadecyl vinyl ether (C16E1VE) as a phase change material was fabricated using ethylene glycol monovinyl ethersodium and bromohexadecane as raw materials through sodium alkoxide method. Poly(ethylene glycol hexadecyl vinyl ether)(PC16E1VE) was synthesized by living cationic polymerization. The molecular weight and its distribution were characterized using gel permeation chromatography. Sheath/core polymeric nanofibers were coaxially electro-spun using it as the core material, and poly(acrylonitrile-co-vinylidene chloride) as a sheath. The composition, phase change properties, thermal stability of C16E1VE, PC16E1VE and the surface morphology of the fibers were characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), field emission scanning electronic microscopy(FESEM) and transmission electronic microscopy (TEM), respectively. The results show that, C16E1VE, PC16E1VE and the nanofiber are excellent phase change materials with steady structure, high heat enthalpy and thermal stability. Both the melting and crystallizing enthalpies of PC16E1VE are about 84 J/g. The peak melting temperature and crystallizing temperature are 27.5 and 17.5 oC, respectively. It is thermal stable below 200 oC. These properties indicate that this phase change material can be widely used as a polymeric phase change material in high temperature environments. When the concentration of the P(AN-co-VDC) aqueous solution and PC16E1VE sheath and core spinning solutions were 15 wt%, 60 wt% and spun at flow rates of 1.25 mL/h, 0.375 mL/h, respectively. The fibers show uniform diameters and stable sheath/core structures. Both the melting and crystallizing enthalpies of the nanofibers are about 46 J/g. The peak melting temperature and crystallizing temperature are 34.7 and 23.5 oC, respectively. It is a heat energy storage material with excellent properties.