简介:Inthispaper,anabinitio,localdensityfunctional(LDF)methodwasusedtoexploretherelationshipbetweenthemolecularpropertiesofadditivesandthelubricatingperformanceofaluminumrollingoil.Thestructuralpropertiesofbutylstearate,dodecanol,docosanol,andmethyldodecanoatewerestudiedaccordingtothedensityfunctionaltheory.Thecalculateddatashowedthattheatomsinoraroundthefunctionalgroupsmightbelikelythereactingsites.Becauseofthedifferentfunctionalgroupsandstructureofesterandalcohol,twotypesofcomplexadditives,dodecanolandbutylstearate,methyldodecanoateandbutylstearate,respectively,werechosenforstudyingtheirtribologicalpropertiesandperformingaluminumcoldrollingexperiments.Thetestresultsagreedwiththecalculatedresultsverywell.Thecomplexester,viz.methyldodecanoateandbutylstearate,hadthebestlubricatingperformancewithafrictioncoefficientof0.0841andapermissive-rollingthicknessof0.040mmascomparedwiththatofdodecanol-butylstearate-baseoilformulation.
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简介:ThemesoporousAl-SBA-15zeolitewasobtainedviaimpregnationofpuresilica-basedSBA-15zeolitewithaluminumnitrate.TheAl-SBA-15samplewascalcinedinairat800℃for6handhydrothermallytreatedatnear100℃for120h,respectively,andthenthethermalandhydrothermalstabilityofAl-SBA-15samplewasinvestigatedbyX-raydiffractometry(XRD),scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM)andnitrogenadsorptionanddesorptiontechniques.TheAl-SBA-15samplewasalsostudiedby27Alnuclearmagneticresonance(27AlNMR)andammoniatemperatureprogrammeddesorption(NH3-TPD)techniques.Inaddition,thecatalyticactivityofAl-SBA-15zeolitewasinvestigatedbytheFriedel-Craftsreactionsof2,4-di-tert-butylphenolwithcinnamylalcohol.ThetestresultsshowedthatthethermalandhydrothermalstabilityofAl-SBA-15zeolitewasbetterthanthatofSBA-15zeo-lite.TheAl-SBA-15zeolitesamplepreparedbyimpregnationmethodexhibitsmoreframeworkaluminumspeciesandAl-O-Siunits.Therefore,thenumberofthesurfacehydroxylgroupswasreduced,resultinginthestabilizationofframeworkstructureofAl-SBA-15zeolite.Thealuminumspeciescanformweakandmedium-strongacidsiteswithcatalyticactivity.