Poly(mono/diethylene glycol n-tetradecyl ether vinyl ether)s with Various Molecular Weights as Phase Change Materials

Abstract

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.

Preparation of liquid polycarbosilane containing vinyl ether group and its rapid curing through thiol‐ene click reaction

“…After the chlorination of LHBPCS, a new absorption peak corresponding to Si–Cl group appeared at 460–490 cm −1 . 16–30 After incorporating the 2‐HEVE, the absorption peak corresponding to Si–Cl group disappeared, and the absorption peaks corresponding to vinyl ether group appeared at 3116 cm −1 (=C–H stretching), 1616 cm −1 (C=C stretching), and 1219 cm −1 (=C–O stretching) 31,32 . In addition, compared with the raw LHBPCS, the intensity of peaks at 2930 and 2880 cm −1 (C–H stretching of linkage structure –CH 2 –CH 2 –O–) increased significantly 33 .…”

“…[16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] After incorporating the 2-HEVE, the absorption peak corresponding to Si-Cl group disappeared, and the absorption peaks corresponding to vinyl ether group appeared at 3116 cm −1 (=C-H stretching), 1616 cm −1 (C=C stretching), and 1219 cm −1 (=C-O stretching). 31,32 In addition, compared with the raw LHBPCS, the intensity of peaks at 2930 and 2880 cm −1 (C-H stretching of linkage structure -CH 2 -CH 2 -O-) increased significantly. 33 Meanwhile, the absorption peak corresponding to the hydroxy group of 2-HEVE did not exist and the absorption peak corresponding to Si-O stretching at 1100-1050 • cm −1 appeared in the FT-IR spectrum of VE-LHBPCS, indicating the condensation reaction between chlorinated LHBPCS and 2-HEVE proceeded.…”