高抗氧化低硫柔性石墨复合密封材料研究

A study of low-sulfur, high-inoxidizable filexible graphitre based sealing composite

针对目前石墨类密封制品抗氧化和密封性能差、易泄露等问题 ,选用高锰酸钾和浓硫酸做混合氧化剂、三氯化铁做催化插入剂、少量过氧化氢做催化剂 ,采用半固相浸渍法制备可膨胀石墨 ,再将其用蔗糖硼酸脂溶液浸渍、脱水、低温干燥、高温膨胀后压制成高抗氧化低硫柔性石墨复合密封材料 .制品含硫量低于 5 .0× 10 -4,抗氧化能力增强一倍以上 ,在预紧力 70MPa ,介质压力 10 .0MPa的情况下泄漏率小于 0 .0 0 0 1.研究结果表明采用这种新工艺可以改善石墨复合密封材料性能 ,从而更好地满足使用要求 .

Since that the exiting graphite based sealants have some drawbacks such as weak inoxidizability and low sealing capability, a new technology is proposed for preparing low sulfur and high inoxidizable expandable graphite. At first, the low sulfur expandable graphite is prepared by half solid phase maceration and potassium permanganate, in which concentrated sulfuric acid is adopted as antioxidant, ferric trichloride as inserting agent. Then it is macerated in cane sugar borate, dehydrated under low temperature and expanded under high temperature. At last it is made low sulfur high inoxidizable flexible graphite based sealing composite. The sulfur content of the prepared specimen is lower than 5.0×10 -4 ,the leakage rate is lower than 10 -4 while the pretightening load and medium pressure are 70 MPa and 10.0 MPa respectively and the inoxidizability is doubled. It is proved that with novel technology, the graphite based sealing composite can be improved and therefore, it can fulfill the requirements better.