聚醚聚氨酯双离子型离聚物的介电性能研究

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.

STUDY ON THE DIELECTRIC PROPERTY OF POLYETHER-POLYURETHANE ZWITTERIONMERS

Polyether polyurathane based on 4,4'-diphenylmethane diisocyanate (MDI), N-methyl di-ethanolamine. (MDEA) and pplytetramethylene oxide (PTMO) were synthesized in the tertiary molar ratio of 2:1:1. As a result of the reaction of the tertiary amine of MDEA with γ-propane Sulfone, a series of zwitterionomers were prepared in different degrees of sulfo-nation. The dielectric properties of these samples were determined in different temperatures ( - 150 to 30℃) and frequencies (20 Hz to 100 kHz), It was found that as the.degree of sul-fonation increases, the real permittivity (ε') is increased and the dielectric loss peak of a-relaxation shifts to lower temperatures indicating as improvement of phase seperation and the activation energy of α-relaxation (Ha) was decreased while thet of β-relaxation (Hβ) was nearly unchanged. The results of the dielectric measurement coincide with the dynamic mechanical analysis.