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Galactitol hexa palmitate (GHP) as a phase change material (PCM) was fabricated via an esterification reaction of galactitol with palmitoyl chloride. A series of sheath/core composite submicrometer fibers were coaxially electro-spun using poly(acrylonitrile-co-vinylidene chloride) (P(AN-co-VDC)) as a sheath and the GHP as a core. The phase change properties, thermal stability, and the surface morphology of the fibers were characterized using field emission scanning electronic microscopy (FE-SEM), transmission electronic microscopy (TEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), etc. The results show that coaxial submicrometer fibers with a smooth surface and average diameter of 796 nm were electro-spun. The optimum feed rate of the sheath and core components for fabricating thermo-regulated submicrometer fibers with high enthalpies are 1.25 and 0.125 mL/h, respectively. The fiber can absorb 55 J/g of heat energy at approximately 23.2℃ and release 54 J/g at approximately 20.3℃. By contrast, the enthalpy of the P(AN-co-VDC)/GHP submicrometer fiber is higher than the previously published results.

At present, research on the relationship of comb-like polymer phase change material structures and their heat storage performance is scarce. Therefore, this relationship from both micro and macro perspectives will be studied in this paper. In order to achieve a high phase change enthalpy, ethylene glycol segments were introduced between the vinyl and the alkyl side chains. A series of poly(mono/diethylene glycol n-tetradecyl ether vinyl ethers) (PC 14 E n VEs) (n = 1, 2) with various molecular weights were polymerized by living cationic polymerization. The results of PC 14 E 1 VE and PC 14 E 2 VE showed that the minimum number of carbon atoms required for side-chain crystallization were 7.7 and 7.2, which were lower than that reported in the literature. The phase change enthalpy 89 J/g (for poly(mono ethylene glycol n-tetradecyl ether vinyl ethers)) and 86 J/g (for poly(hexadecyl acrylate)) were approximately equal. With the increase of molecular weight, the melting temperature, the melting enthalpy, and the initial thermal decomposition temperature of PC 14 E 1 VE changed from 27.0 to 28.0 • C, from 95 to 89 J/g, and from 264 to 287 • C, respectively. When the number average molar mass of PC 14 E n VEs exceeded 20,000, the enthalpy values remained basically unchanged. The introduction of the ethylene glycol chain was conducive to the crystallization of alkyl side chains.