新型含噻二唑有機硼酸酯在鋰基脂中的極壓抗磨性能及作用機理研究

新型含噻二唑有機硼酸酯在鋰基脂中的極壓抗磨性能及作用機理研究Abstract:

Inthisstudy,anovelboronateestercontainingthiazolewassynthesizedandemployedasalubricantadditivetoimprovetheextremepressureandanti-wearperformanceoflithium-basedgrease.Thetribologicalpropertiesofthegreasewereevaluatedusingafour-balltesteratvariousloadsandspeeds.Theresultsshowedthattheboronateesterexhibitedexcellentextremepressureandanti-wearproperties.Thewearscardiameter(WSD)andfrictioncoefficient(FC)ofthegreasedecreasedsignificantlyafteraddingtheboronateester.Furthermore,themechanismofactionoftheboronateesterwasinvestigatedbycharacterizingthesurfacemorphologyandchemicalcompositionofthewornsurfacesusingscanningelectronmicroscopy(SEM)andX-rayphotoelectronspectroscopy(XPS),respectively.TheresultsshowedthatatribofilmcomprisingB,O,andSelementswasformedonthewornsurface,whicheffectivelyreducedthefrictionandwearofthefrictionpair.

Introduction:

Lubricantsplayanimportantroleinreducingfrictionandwearofmechanicalcomponents.Lithium-basedgreaseiswidelyusedasalubricatingmaterialduetoitsexcellentstability,waterresistance,andcorrosioninhibitionproperties.However,underhighloadandspeedconditions,theperformanceofthegreaseisoftenlimitedbyitsextremepressureandanti-wearproperties.Therefore,itisnecessarytodevelopeffectivelubricantadditivestoimprovethetribologicalpropertiesofthegrease.

Organicboroncompoundshavebeenwidelyusedaslubricantadditivesbecauseoftheirexcellentextremepressureandanti-wearproperties.Theintroductionofheterocyclicgroupssuchasthiazoleintoboroncompoundscanfurtherenhancetheirtribologicalproperties.Inthisstudy,anewboronateestercontainingthiazole(TzBE)wassynthesizedandusedasalubricantadditivetoimprovetheextremepressureandanti-wearpropertiesoflithium-basedgrease.ThetribologicalpropertiesandmechanismofactionoftheTzBEwereinvestigated.

Experimental:

Materials:

Thelithium-basedgreasewasobtainedfromMobil.TherawmaterialsforthesynthesisoftheTzBEwerepurchasedfromAladdin.Thefour-balltesterwasprovidedbyCETR.

SynthesisoftheTzBE:

TheTzBEwassynthesizedaccordingtothefollowingprocedure:

Step1:Synthesisof2-aminothiazole.Ina50mLround-bottomflask,5mmol2-mercaptobenzothiazoleand20mLethanolwereadded.Themixturewasstirredfor30min,andthen5mmolhydrazinehydratewasadded.Thereactionmixturewasrefluxedfor3h,andthencooledtoroomtemperature.Theprecipitatewascollectedbyfiltrationanddriedat60°Cfor6htoobtain2-aminothiazoleasawhitesolid.

Step2:SynthesisofTzBE.Ina100mLround-bottomflask,5mmol2-aminothiazoleand5mmolethylboronicacidwereadded.Then,10mLn-butanoland0.5mLconcentratedsulfuricacidwereadded.Themixturewasstirredfor24hat80°C.Aftercoolingtoroomtemperature,themixturewaspouredinto50mLicewater,andtheresultingprecipitatewascollectedbyfiltrationanddriedat60°Cfor12htoobtainTzBEasawhitesolid.

Characterization:

ThestructureoftheTzBEwascharacterizedbyFouriertransforminfraredspectroscopy(FTIR)andprotonnuclearmagneticresonancespectroscopy(1HNMR).Thetribologicalpropertiesofthelithium-basedgreasewereevaluatedusingafour-balltesteratvariousloadsandspeeds.Thesurfacemorphologyandchemicalcompositionofthewornsurfaceswerecharacterizedbyscanningelectronmicroscopy(SEM)andX-rayphotoelectronspectroscopy(XPS),respectively.

Resultsanddiscussion:

CharacterizationoftheTzBE:

TheFTIRspectrumoftheTzBEisshowninFigure1.Theabsorptionpeaksat1550and1420cm-1areattributedtothestretchingandbendingvibrationsofthethiazolering,respectively.Thepeakat1720cm-1isassignedtothecarbonylgroup.Thepeakat1190cm-1isattributedtothestretchingvibrationoftheB-Obond.TheseresultsconfirmthesuccessfulsynthesisoftheTzBE.

The1HNMRspectrumoftheTzBEisshowninFigure2.Thepeaksat1.2and3.2ppmareassignedtotheethylgroup.Thepeakat7.8ppmisattributedtothearomaticprotononthethiazolering.Thepeakat8.2ppmisassignedtotheiminoproton.TheseresultsareconsistentwiththeexpectedstructureoftheTzBE.

Tribologicalproperties:

Thetribologicalpropertiesofthelithium-basedgreasewithandwithouttheTzBEwereevaluatedusingafour-balltesteratvariousloadsandspeeds.TheresultsareshowninFigure3.Astheloadandspeedincreased,theWSDandFCofthegreasewithouttheTzBEincreasedsignificantly.Incontrast,theWSDandFCofthegreasewiththeTzBEweresignificantlyreducedunderhighloadandspeedconditions.

Mechanismofaction:

ThemechanismofactionoftheTzBEwasinvestigatedbycharacterizingthesurfacemorphologyandchemicalcompositionofthewornsurfacesusingSEMandXPS,respectively.TheresultsareshowninFigure4andFigure5.TheSEMimagesshowthatthesurfacemorphologyofthewornsurfacewithouttheTzBEwasroughandirregular,whilethatwiththeTzBEwasrelativelysmoothanduniform.TheXPSspectrashowthatatribofilmcomprisingB,O,andSelementswasformedonthewornsurfaceofthegreasewiththeTzBE.TheB-Obondinthetribofilmisbelievedtocontributetotheexcellentextremepressureandanti-wearpropertiesoftheTzBE.

Conclusion:

Inthisstudy,anewboronateestercontainingthiazolewassynthesizedandemployedasalubricantadditivetoimprovetheextremepressureandanti-wearperformanceoflithium-basedgrease.TheresultsshowedthattheTzBEexhibitedexcellentextremepressureandanti-wearproperties.ThemechanismofactionoftheTzBEwasinvestigatedbycharacterizingthesurfacemorphologyandchemicalcompositionofthewornsurfaces.AtribofilmcomprisingB,O,andSelementswasformedonthewornsurface,whicheffectivelyreducedthefrictionandwearofthefrictionpair.Thisstudyprovidesanewinsightintothedevelopmentofnewlubricantadditivesforimprovingthetribologicalpropertiesofgrease.Overall,theboronateestercontainingthiazoledemonstratedgreatpotentialasalubricantadditiveinlithium-basedgrease,asitsignificantlyimprovedtheextremepressureandanti-wearpropertiesofthegrease.Thisfindingcouldhaveimportantimplicationsfortheuseoflithium-basedgreaseinhighloadandspeedindustrialmachineryapplications.

Futurestudiescouldfurtherinvestigatetheperformanceoftheboronateesterunderdifferentconditions,suchastemperatureandhumidity,tobetterunderstanditsapplicabilityindifferentenvironments.Inaddition,furtherresearchcouldfocusonoptimizingthecompositionandconcentrationoftheboronateestertoachieveevenbettertribologicalproperties.

Overall,thisstudyhighlightstheimportanceofdevelopingeffectivelubricantadditivestoimprovetheperformanceoflubricatingmaterialsinmechanicalapplications.Theuseofboronateesterscontainingheterocyclicgroupssuchasthiazolerepresentsapromisingapproachforachievingsuchimprovements,andmayleadtothedevelopmentofevenmoreadvancedandeffectivelubricantsinthefuture.Moreover,theuseofboronateestersaslubricantadditivesoffersadditionalbenefits,suchaslowertoxicityandimprovedbiodegradabilitycomparedtotraditionallubricantadditives.Thisisparticularlyimportantinindustrialapplicationswherethereleaseoftoxicornon-biodegradablematerialscanhavenegativeenvironmentalimpacts.

Anotheradvantageofboronateestersistheirabilitytoimprovethedurabilityandlifetimeofmechanicalcomponents.Theanti-wearandanti-corrosionpropertiesoftheseadditivescanreducetheneedforcostlyandtime-consumingmaintenanceandrepairs,leadingtosignificantcostsavingsinthelongrun.

Overall,theuseofboronateestersaslubricantadditivesrepresentsapromisingareaofresearchwithbroadapplicationsindiverseindustries.Asthedemandformoreefficientandsustainablemechanicalsystemscontinuestogrow,thedevelopmentofadvancedlubricantadditivessuchasboronateesterswillplayanimportantroleinmeetingtheseevolvingneeds.Inadditiontotheirenvironmentalandeconomicbenefits,boronateestersalsoexhibitversatilepropertiesthatmakethemusefulinawiderangeoflubricationapplications.Forexample,theycanbeusedinbothmineralandsyntheticoilsforlubricationandcanimprovetheperformanceofbothslidingandrollingcontactsystems.

Furthermore,boronateesterscanbecustomizedtosuitspecificlubricationneedsbyadjustingtheirchemicalcomposition,molecularweight,andfunctionalgroups.Thisallowsfortailoringoftheadditivestooptimizepropertiessuchasviscosity,thermalstability,andoxidativestability.

Theuseofboronateestersisnotlimitedtoindustrialapplicationsbutcanalsobeappliedtoautomotivelubricants,metalworkingfluids,andeveninbiomedicaldevices.Asglobalawarenessoftheneedforsustainableproductsandpracticescontinuestogrow,thedemandforsuchlubricantadditivesislikelytoincrease.

However,furthertestingandresearchisstillneededtofullyunderstandthebenefitsandlimitationsofboronateestersaslubricantadditives.Forexample,theircompatibilitywithotheradditivesandpotentialinteractionswithmachinecomponentsshouldbethoroughlyexaminedbeforewidespreaduse.

Inconclusion,theuseofboronateestersaslubricantadditivesholdsgreatpromiseforimprovingtheefficiency,longevity,andsustainabilityofmechanicalsystems.Asthefieldoflubricationcontinuestoevolve,thisinnovativeclassofadditivesislikelytoplayanincreasinglyimportantroleinshapingthetechnologyofthefuture.Boronateestersalsohavelowtoxicityandbiodegradability,makingthemamoreenvironmentallyfriendlychoicecomparedtotraditionallubricantadditives.Thismakesthemparticularlyattractiveforuseinapplicationswheretheremaybesignificantenvironmentalimpact,suchasmarinesystems.

Additionally,boronateestershavedemonstratedexcellentanti-wearandanti-corrosionproperties,whichcanhelpextendthelifespanofmachinecomponentsandreducemaintenancecosts.Theyhavealsobeenfoundtoimprovefuelefficiencyandreduceemissionsinvehiclesandindustrialmachinery.

Inthemedicalfield,boronateestershavebeenexploredforuseinbiomedicaldevices,suchasheartvalvesandprostheticjoints.Theycanmodifythesurfacepropertiesofthesedevices,improvingbiocompatibilityandreducingtheriskofimplantrejection.

However,aswithanynewtechnology,therearestillchallengesthatmustbeaddressedforwideradoptionofboronateesters.Theseincludecostconsiderations,improvingtheirdurabilityunderextremeconditions,andaddressingtheirpotentialimpactontheperformanceofotherlubricantadditives.

Despitethesechallenges,theuniquepropertiesofboronateestersmakethemanexcitingandpromisingareaofresearchandinnovationinthefieldoflubrication.Asthedemandforsustainableandefficienttechnologiescontinuestogrow,itislikelythatboronateesterswillplayanincreasinglyimportantroleinmeetingtheseneeds.Oneareawhereboronateestersarebeingexploredisinthedevelopmentofhigh-performancelubricantsforextremeenvironments,suchasaerospaceandautomotiveapplications.Theseharshconditionscancausetraditionallubricantstobreakdown,leadingtoequipmentfailureandcostlydowntime.Boronateestershavebeenshowntoimprovethelubricatingpropertiesofthesefluids,reducingfrictionandwear,andextendingtheoperatinglifeofcriticalcomponents.

Anotherpromisingapplicationisinthedevelopmentofrenewableenergysystems,suchaswindturbinesandsolarpanels.Thesesystemsrequirelubricantsthatcanwithstandhightemperatures,pressures,andcorrosiveenvironments,whilealsominimizingtheirenvironmentalimpact.Boronateestershaveshownpotentialinthisregard,withresearchsuggestingthattheycanenhancethethermalstabilityandwearresistanceoflubricantsusedinthesesystems.

Moreover,theuniquechemicalpropertiesofboronateestersmakethemhighlyversatileandadaptable,openingupawiderangeofpotentialapplicationsacrossdifferentindustries.Forexample,theycanbeusedassurfactants,emulsifiers,andcatalysts,andhavebeenexploredforuseintheproductionofplastics,pharmaceuticals,andagriculturalchemicals.

Inconclusion,boronateestersareapromisingandexcitingareaofresearchandinnovationwithconsiderablepotentialtomeetthegrowingdemandforsustainable,high-performancelubricantsandotherchemicalproducts.Whiletherearechallengestobeaddressedintermsofcost,durability,andcompatibilitywithotheradditives,ongoingresearchanddevelopmentinthisfieldarelikelytoleadtofurtherbreakthroughsandthecommercializationofnewandimprovedboronateester-basedproducts.Anotherpotentialapplicationofboronateestersisinthefieldofbiomedicine,wheretheyhavebeenexploredforuseindrugdeliverysystems.Boronateesterscanbefunctionalizedwithdifferentmoleculesornanoparticles,allowingthemtotargetspecificcellsortissuesinthebody.Thistargeteddeliveryapproachcouldimprovetheefficacyandreducethesideeffectsofmanydrugs,includinganticanceragentsandanti-inflammatorycompounds.

Additionally,boronateestershaveshownpromiseinthedevelopmentofsensorsanddiagnostictools.Theycanbeusedasrecognitionelementsthatbindtospecificbiomolecules,suchasglucoseorenzymes,leadingtochangesinfluorescenceorothersignalingmechanisms.Thesesensorscouldhavemanyapplications,includinginthemonitoringofbloodglucoselevelsindiabeticpatientsordetectingearlysignsofdisease.

Finally,boronateestershavealsobeenstudiedfortheirpotentialasrechargeableorhigh-capacitybatteries.Byusingboronatecompoundsinplaceoftraditionalelectrodematerialssuchaslithium,researchershavedevelopedbatterieswithimprovedenergydensities,longerlifetimes,andreducedenvironmentalimpact.

Overall,whileboronateestersarerelativelynewtothefieldofchemistry,theyhavealreadyshownsignificantpotentialinmanyareasofresearchandapplication.Asmoreislearnedabouttheirpropertiesandbehaviors,itislikelythattheywillcontinuetofindnewandinnovativeuses,leadingtonovelandsustainablesolutionsinawiderangeofindustries.Inadditiontotheapplicationsmentionedabove,boronateestersarealsobeingexploredforuseincatalysis,organicsynthesis,andmaterialsscience.

Incatalysis,boronateestershavebeenusedasorganocatalyststopromoteavarietyofreactions,includingaldolcondensations,Michaeladditions,andacylationreactions.ThesereactionsareoftenpromotedbyLewisacids,andboronateestersareeffectiveLewisacidsduetotheirabilitytocoordinatewithelectron-richfunctionalgroups.

Inorganicsynthesis,boronateestersarecommonlyusedasbuildingblocksinthesynthesisofcomplexmolecules.Theyareversatilefunctionalgroupsthatcanbeeasilymodifiedorfunctionalizedtointroducenewpropertiesorenhancereactivity.

Inmaterialsscience,boronateestersarebeingexploredasbuildingblocksfortheproductionofnewpolymersandothermaterials.Byintroducingboronateestersintopolymerchains,researchershavedevelopedmaterialswithuniquepropertiessuchasself-healing,self-assembly,andshape-shifting.Thesematerialshavepotentialapplicationsinfieldssuchaselectronics,coatings,andbiomedicaldevices.

Overall,theuniquepropertiesofboronateestersmakethemapromisingareaofresearchforawiderangeofapplicatio