Long-Branched Structure of Polybutadienes Analyzed by Rheology

Abstract

forlong-branchedPBsincreaseswithPBconcentration,andalsoincreasesfor morecomplexlong-branchedstructures.ThevaluesofG′c −2 forY2andVwerenotdependentonconcentration.There-sultsshowedthatY2andVhavelinearmolecularstructuresandthatY1,Co1,andCo2havelong-branchedstructures, withtheorderofcomplexitybeingY1>Co1>Co2.Fromthedampingfunctionsevaluatedbylarge-deformationstressrelaxation measurements of the 30% PB solutions, the order of long-branched structural complexity was Y1>Co1>Co2>V≈Y2.ThisorderwasessentiallythesameasthatbasedonthelinearviscoelasticityofthePBsamples.Therheologicalmethodinthisstudyprovidesstructuralinformationaboutlong-branchedPBs.