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以4,4＇-二苯基甲烷二异氰酸酯(MDI)、N-甲基二乙醇胺(MDEA)和聚四氢呋喃(PTMD)以2:1:1(mol比)合成聚醚型聚氨酯,MDEA的叔胺基与γ-丙磺内酯反应,制备了不同磺化程度的双离子型离聚物.在不同温度与频率(-150-30℃,20Hz—100KHz)下,测定了其介电性能.结果表明,随离子化程度的提高,ε＇增大,α弛豫介电损耗峰移向低温,说明相分离越趋完善;β弛豫单元的活化能(△Hβ)基本不变;α弛豫单元的活化能(△Hα)依次变小.介电测量结果与动态力学方法研究结果相吻合.
Polyether polyurethanes were synthesized in 4,4’-diphenylmethane diisocyanate (MDI), N-methyldiethanolamine (MDEA) and polytetrahydrofuran (PTMD) at a molar ratio of 2: 1: 1 Amino groups were reacted with γ-propane sultone to prepare double ionomers with different degree of sulfonation.The dielectric properties were measured at different temperatures and frequencies (-150-30 ℃, 20Hz-100KHz). The results show that as the degree of ionization increases, ε ’increases and α relaxation dielectric loss shifts to low temperature, indicating that the phase separation becomes more perfect. The activation energy (ΔHβ) of β relaxation unit does not change substantially. The activation energies (ΔHα) of the units decrease in turn, and the dielectric measurements agree with those of the dynamic mechanical method.