氮化合物对润滑油基础油氧化安定性影响的本质认识

UNDERSTANDING OF THE NATURE OF THE INFLUENCE OF NITROGEN COMPOUNDS ON OXIDATION STABILITY OF LUBE BASE OIL

采用烃类氧化过程中氢过氧化物浓度分析、动态吸氧研究烃类氧化特征及氮化合物氧化产物结构鉴定相结合的方法,研究了氮化合物影响烃类氧化的作用机理,并通过试验分析讨论了氮化合物与基础油氧化性能关系的复杂性。结果表明,氮化合物在烃类初始氧化过程中起降低氢过氧化物浓度的作用,氮化合物本身通过促进氢过氧化物分解而加速烃类氧化,氮化合物的氧化物则起抑制烃类氧化的作用,两种作用互为竞争。氮化合物与基础油氧化安定性的关系比较复杂,受氮化合物含量、氧化时间、催化剂形态及基础油中氮化合物组成间的相互作用的影响。

The chemical mechanism of the nitrogen compounds in hydrocarbon oxidation was investigated by the combined method of determining hydroperoxide concentration, studying the oxidation characteristics of hydrocar- bon with dynamic oxygen uptake method and identifying the structure of oxidation products of nitrogen compounds. Based on experimental results, the complicated relations between nitrogen compounds and oxidation properties of base oil were analyzed and discussed. The results indicated that nitrogen compounds could reduce the hydroperoxide con-centration in oxidation reaction initial period. Nitrogen compounds accelerated hydrocarbon oxidation through promoting the decomposition of hydroperoxides. The oxidation products of nitrogen compounds could prevent the hydrocarbons from oxidation. So the actions of nitrogen compounds and their oxidation products were mutual competitive. The rela-tions between nitrogen compounds and oxidation stability of lube oil were complicated because they were influenced by the content of nitrogen compound, oxidation time, catalyst form and interactions between the chemical components of the nitrogen compounds in lube base oil.