|
|
过程工程学报 2005
CharacterizationoftheMechanicalPropertiesofUrea-FormaldehydeMicrocapsulesKeywords: urea-formaldehydemicrocapsule,micromanipulationtechnique,mechanicalproperties,linearelasticity,Young￠smodulus Abstract: Themechanicalpropertiesofurea-formaldehyde(U-F)microcapsulesweredeterminedusingamicromanipulationtechniqueandatheoreticalmodel.Loading-unloading,compressingandholding,andcompressingtoburstingtestsatdifferentspeedsbetweentwoparallelplatesforsinglemicrocapsuleswerecarriedout.ItwasfoundthattheU-Fmicrocapsuleswerevisco-elastic(mainlyelastic)atsmallcompressivedeformation,andplasticunderlargedeformation.Thetransitionpointfromelastictoplasticoccurredatabout(14±0.2)%compressivedeformation.Allthemicrocapsuleswoulddisruptwhencompressedtoabout(17±0.2)%deformation,andtheburstforceincreasedlinearlywiththeirdiameter.Compressingspeedhadnoremarkableeffectonbothburstforceandburstdeformation.Liquidfillednon-permeableandlinearelasticsphericalmembranemodelwasusedtosimulatetheuniaxialcompressionofsinglemicrocapsule,anditsmembranemodulusEhwasdeterminedbyfittingmodelpredictiontoexperimentaldata.TheaveragevalueofEhwasestimatedtobe(478±8)N/m.
|
