摘要
采用量子化学方法计算了聚全氟甲乙醚苯酰胺 (化合物 I)与聚全氟甲乙醚氧自由基 ( Rf O· )的结合能以及与 Fe原子的化学吸附作用能 ,探讨了该化合物作为抗氧抗腐添加剂的作用机理。结果表明 ,Rf O·自动结合于苯环的 C7原子上 ,生成 C—O键和稳定的加成产物 ,其结合能为 -4 1 7.33k J/mol;化合物 I能与 Fe原子形成较稳定的络合物 ,其化学吸附作用能为 -1 0 5.0 2 k J/mol。合成了聚全氟甲乙醚苯酰胺抗氧抗腐添加剂 ( PFPA) ,并进行了 UV和 IR光谱分析 ,PFPA分子中苯环的 UV和 C O的 IR特征吸收峰分别为 2 4 0 .7nm和 1 71 3.9cm- 1。抗氧抗腐性能测试结果表明 ,加入 PFPA添加剂 ,能使氟醚润滑油的失重较空白样减少近 7倍 ,使 Al2 O3催化下的热分解温度提高 1 9℃。研究表明 ,聚全氟甲乙醚苯酰胺的最低轨道 ( LOMO)与氧自由基的单占分子轨道 ( SO-MO)相互作用 ,形成亲核加成产物 ,阻止氧自由基 Rf O·的链锁反应和酸性产物的生成。添加剂的最高占有分子轨道 ( HOMO)与 Fe原子的 LOMO相互作用形成稳定的化学吸附态和油膜 。
The combination energy of perfluoropolyalkyletherphenyl amide (Compound I) to perfluoropolyalkylether oxygen radical (RfO·) and the chemical adsorption energy of compound I to Fe atom have been obtained by quantum chemical calculation. Action mechanism of anti-oxidation and anti-corrosion is explored. It is found that the RfO· is combined automatically with C7 atom of the benzene ring of compound I with combination energy of -417.33 kJ/mol, and N atom or amide can react with d-orbital of Fe atom to form chemical adsorption state with energy of -105.02 kJ/mol. Perfluoropolyalkyletherphenylamide (PEPA) was synthesized and characterized by UV and IR. Strong absorption peaks at 240.7 nm of UV and 1731.9 cm-1 of IR showed the presence of benzene ring and C=O group of amide. Measurement of anti-oxidant and anti-corrosive behavior indicated that in the presence of synthesized additive, mass loss of perfluoropolyether lubricant decreased about seven times and degradation temperature increased about 19°C as compared with the blank. Theoretical and experimental studies show that the PFPA containing phenyl group and N atom of a lone pair electrons can not only combine with RfO·, but also can react with Fe atom. Action mechanism of anti-oxidation and anti-corrosion is that LOMO of the additive reacts with SOMO of RfO· to form nucleophilic addition product and to terminate oxygen radical reaction. HOMO of the additive reacts with LOMO of Fe atom to form chemical adsorption state and oil film on metal surface, which can inhibit oil catalytic degradation and protect metals from corrosion.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2001年第4期49-54,共6页
Acta Petrolei Sinica(Petroleum Processing Section)
