二氧化锰硫化剂对聚硫密封剂性能的影响

采用X射线衍射(XRD)法和扫描电镜(SEM)对不同晶型的二氧化锰(MnO2)进行了表征;然后将其配制成聚硫密封剂的硫化剂,考查了不同硫化剂对聚硫密封剂的力学性能、耐热性能和耐溶剂性能等影响。结果表明:γ-MnO2或β-MnO2硫化聚硫密封剂的耐热性能和耐水性能优于α-MnO2硫化聚硫密封剂;γ-MnO2硫化聚硫密封剂的性能相对最好,其经180℃热处理2 h后的拉伸强度增加了7.1%,在60℃水中浸泡7 d后的拉伸强度下降了39%;由不同晶型MnO2硫化的聚硫密封剂,其耐3#航空燃油性能相当;γ-MnO2最适合用作聚硫密封剂的硫化剂。

Influences of MnO2 vulcanizing agent on properties of polysulfide sealant

The MnO2 with different crystal structures were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM),then the influences of different vulcanizing agents,which were made from different MnO2 with different crystal structures for polysulfide sealant,were investigated on mechanical properties,heat-resistance and solvent-resistance of polysulfide sealant.The results showed that the heat-resistance and water-resistance of polysulfide sealant cured by γ-MnO2 or β-MnO2 were better than those by α-MnO2.The polysulfide sealant cured by γ-MnO2 had the reversely best properties,its tensile strength was increased by 7.1% after aging at 180 ℃ for 2 h or was decreased by 39% in 60 ℃ water for 7 d.The polysulfide sealants,which were cured by MnO2 with different crystal structures,had good 3# aviation fuel-resistance.The γ-MnO2 was a optimal vulcanizing agent for polysulfide sealant.