低内耗聚氨酯灌封胶研制

Preparation of the Low Internal Friction Polyurethane Pouring Sealant

采用聚四氢呋喃醚二醇(PTMG)、聚己二酸乙二醇酯(PBA)、聚环氧丙烷醚多元醇(PPG)、甲苯二异氰酸酯(TDI)等为原料,制备了一种高强度、低内耗聚氨酯灌封胶。讨论了多元醇种类和异氰酸酯含量对灌封胶材料力学性能、电学性能、动态热机械性能的影响。结果表明,当采用质量分数80%的PTMG和20%的PBA作为软段,且NCO质量分数达到6.5%时,灌封胶拉伸强度为56MPa,伸长率为581%,撕裂强度为120kN/cm,体积电阻为4.8×1013Ω.cm,内耗峰峰高tanδ=0.22;适用于高振动工况条件下电子元器件的灌封。

Polyurethane （PU） pouring sealant of high strength and low internal friction was synthesized with polytetram-ethylene glycol （PTMG）, polyethylene adipate（ PBA）, polyoxypropylene glycol（ PPG）, toluene diisocyanate （TDI）. The effects of the polyol type and NCO content on mechanical properties, electrical properties and dynamic thermo-mechanical properties of pouring sealant were discussed. The results showed that the pouring sealant tensile strength was 56 MPa, elongation at break was 581%, tear strength was 120 kN/cm, volume resistance was 4. 8 × 10^13 Ω·cm and internal friction peak tanδ was 0. 22 when the type of polyol was 80% PTMG and 20% PBA, NCO content was 6. 5%. It could be used as the electronic component sealant which worked in high frequent vibration conditions.