五龄黑水虻油脂衍生物作为润滑油添加剂的性能研究

Properties Study of Fifth-Instar Black Soldier Fly Fats Derivative as Lubricant Additive

为探索黑水虻幼虫体内的粗油脂作为生物润滑油添加剂的应用可行性,本文中以五龄黑水虻虫体的粗油脂为原料,通过纯化、水解反应和酯化反应合成了虫体油脂衍生物.采用核磁共振波谱、傅里叶红外光谱和热重分析仪对其结构和热稳定性进行表征,发现其热稳定性良好.采用UMT-TriboLab摩擦磨损试验机和四球摩擦试验机分别研究了虫体油脂衍生物作为润滑油添加剂在点-面和点-点接触模式下的摩擦学性能,并与商用合成酯的性能进行对比.结果表明,在基础油150N中添加质量分数为1%的虫体油脂衍生物时,油品表现出较优的减摩和抗磨效果.在点-面接触模式下,摩擦系数和磨损率相对于基础油分别降低25.0%和92.0%,且在200℃高温下仍能保持减摩效果.在点-点接触模式下,磨损率相对于基础油降低了84.5%.可见虫体油脂衍生物作为润滑油添加剂能够有效提高油品的摩擦学性能.采用接触角试验验证了虫体油脂衍生物作为润滑油添加剂在金属表面的吸附性能.结果表明,虫体油脂衍生物在润滑过程中能够优先吸附在摩擦副的金属表面,形成润滑保护膜,使油品的减摩和抗磨性能提升.通过显微红外光谱和拉曼光谱研究了虫体油脂衍生物的润滑作用机理,表明磨痕表面存在的铁氧化物和碳能够形成润滑膜,防止摩擦副表面的微凸体直接接触,进而改善了油品的摩擦学性能.

In order to explore the feasibility of crude fats from the larvae of black soldier fly as a bio-lubricant additive,the larvae of black soldier fly were fed with pretreated kitchen waste until the fifth-instar in this paper.The crude fats from the larvae were extracted by solvent method and the insect fats derivatives were synthesized by purification,hydrolysis reaction and esterification reaction.In order to evaluate the prospects of the application,physicochemical properties and tribological properties were evaluated and compared with trimethylolpropane trioleate.Trimethylolpropane trioleate was a commercial synthetic ester product with a similar structure to the insect fats derivatives.The structure and thermal stability were characterized by nuclear magnetic resonance spectroscopy,Fourier transform infrared spectroscopy and thermogravimetric analyzer,and the results showed that the thermal stability of the insect fats derivatives was ideal.The oxidation stability was evaluated by high-pressure differential scanning calorimetry,which was found to be better than the commercial synthetic ester.The tribological properties of the insect fats derivatives as lubricant additives in point-on-flat and point-to-point modes were investigated by UMT-TriboLab friction tester and four-ball friction tester,respectively.The results showed that with the addition of 1%of insect fats derivatives to the base oil 150N,the oil exhibited superior friction reduction and anti-wear effects when compared with commercial synthetic esters.In the point-on-flat mode,the commercial synthetic ester as a lubricant additive reduced the friction coefficient and wear rate reduced by 17.5% and 67.2%,respectively,compared with the base oil.In contrast,insect fats derivatives as lubricant additives reduced the friction coefficient and wear rate by 25.0% and 92.0%,respectively,compared with the base oil.The friction reduction effect was maintained at a high temperature of 200℃.In the point-to-point mode,the wear rate was reduced by 84.5% compared with the base oil,exhibiting superior wear resistance performance.The results showed that the insect fats derivatives as lubricant additives could effectively improve the tribological performance of the lubricant.The contact angle measurements on the surface of GCr15 steel were used to verify the adsorption performance of the insect fats derivatives as lubricant additives on the metal surface.It could be indicated that during the lubrication process,the additive could preferentially adsorb on the metal surface of the friction pair,forming a lubricating film and preventing the direct contact of micro-convex bodies on the metal surface,so as to enhance the friction reduction and anti-wear performance of the oil.The lubrication mechanism of insect fats derivatives was investigated by microscopic infrared spectroscopy and Raman spectroscopy.The results showed that the insect fats derivatives were able to adsorb on the surface of the friction pair.The presence of iron oxide and carbon on the surface of the wear marks lubricated by the insect fats derivatives as lubrication additives were able to form a lubricating film,which prevented direct contact with the micro-convex body,thus improving the tribological properties of the oil.In this work,the idea for the application of black soldier fly fats in the field of lubrication was offered,and the recycling of resources was realized,which was in line with the concept of green and sustainable development.