聚脲润滑脂静态热氧老化条件下性能衰退机制研究  

Performance Degradation Mechanism of Polyurea Grease Under Static Thermal-Oxidative Aging Conditions

作　　者：沙光荣 来冰冰 赵启龙 孙一平 王晓波[2,3] 娄文静 刘晓玲[1] SHA Guangrong;LAI Bingbing;ZHAO Qilong;SUN Yiping;WANG Xiaobo;LOU Wenjing;LIU Xiaoling(School of Mechanical and Automotive Engineering,Qingdao University of Technology,Shandong Qingdao 266520,China;State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Gansu Lanzhou 730000,China;Qingdao Key Laboratory of Lubrication Technology for Advanced Equipment,Qingdao Center of Resource Chemistry&New Materials,Shandong Qingdao 266100,China)

机构地区：[1]青岛理工大学机械与汽车工程学院,山东青岛266520 [2]中国科学院兰州化学物理研究所固体润滑国家重点实验室,甘肃兰州730000 [3]青岛市资源化学与新材料研究中心青岛市高端装备润滑技术重点实验室,山东青岛266100

出　　处：《摩擦学学报（中英文）》2024年第8期1074-1083,共10页Tribology

基　　金：泰山学者青年专家计划;中国科学院战略性先导科技专项B类(XDB 0470000)资助。

摘　　要：采用静态热老化方式模拟聚脲基润滑脂在高温工况下的老化行为,根据润滑脂样品在老化过程中红外光谱的变化将其老化过程划分为3个阶段.通过扫描电镜表征热老化后润滑脂微观结构、热重表征热老化后润滑脂的热稳定性,采用流变仪考察润滑脂流变性能的变化,最后探究热老化温度对聚脲基润滑脂老化过程的影响.结果表明:聚脲基润滑脂在热老化过程中,首先稠化剂分子间的缔合程度增加,稠化剂网络结构的交联程度下降,对基础油的束缚能力减弱,润滑脂结构稳定性减弱.随后基础油发生氧化,稠化剂脲分子间部分氢键开始发生断裂,无序的短纤维结构逐渐向均匀的球状颗粒结构转变,润滑脂结构稳定性增强但强度逐渐减弱.随着老化程度的加剧,脲基结构发生改变,稠化剂发生氧化且氧化产物增加,基础油大量流失,导致润滑脂硬化加剧.此外,试验结果表明温度越高,润滑脂老化劣化越迅速,氧化安定性越差,结构变化越快,结构强度越低.Lubricant aging is one of the main causes of rolling bearing failures.Thickener is one of the core components of lubricating greases.Lubricating greases with the different thickeners exit different aging behaviors and mechanisms Polyurea lubricating grease is commonly used in industrial equipment operating under harsh conditions such as high temperature,high speed,and high load due to its excellent performance.The study of the aging mechanism of polyurea lubricating grease is beneficial for understanding the state of lubricating grease,providing data support and theoretical basis for the practical application and further development of lubricating grease.In this article,the aging behavior of polyurea greases under high temperature conditions were investigated by simulating a static thermal aging circumstance.To investigate the decay process of polyurea grease and the effect of temperature on this process under thermal aging conditions at 160,180,200 and 220℃,respectively.The aging process of polyurea grease under the thermal aging condition of 180℃was taken as an example.Based on the differences in infrared spectra during the aging process of polyurea lubricating greases,and combined with the microstructures of the thickeners,the oxidation stabilities,thermal stabilities,and rheological properties of the polyurea lubricating greases,their aging and decline mechanism were studied in detailed.The results indicated that in the early stage of thermal aging of polyurea greases,the degree of association between thickener molecules increased with the increasing of aging time which could inhibit the oxidation of the base oil to some extent.With the continuous effect of thermal effect,the microstructures of thickener fibers changed from disordered short fiber structures to spherical particle structures,the base oil precipitated and began to oxidize.At the same time,the structural stabilities of grease became weak and then strengthens,and the structural strength gradually weakened.At the last stage,hydrogen bonds in th

关 键 词：聚脲基润滑脂 静态热老化 红外光谱 微观结构 流变性 

分 类 号：TH117.2[机械工程—机械设计及理论]