6533b7d8fe1ef96bd126a1ea

RESEARCH PRODUCT

Branched versus linear polyisoprene: Fractionation and phase behavior

Francisco-j. López-villanuevaBernhard A. WolfJohn EckeltFatemeh SamadiHolger Frey

subject

chemistry.chemical_classificationTernary numeral systemMolar massPolymers and PlasticsCyclohexaneChemistryOrganic ChemistryAnalytical chemistryGeneral Physics and AstronomyPolymer architectureFractionationPolymerchemistry.chemical_compoundPhase (matter)Polymer chemistryMaterials ChemistryPolymer fractionation

description

Abstract Branched polyisoprene (PI) was prepared from PI-macromonomers. Linear byproducts of the synthesized polymer were removed by means of inverse spin fractionation, using the solvent cyclohexane (CH) and the precipitant acetone (AC). A well-defined fraction (Mw = 17.5 kg/mol, Mw/Mn = 1.8) of the branched polyisoprene obtained in this manner was used to determine different phase diagrams with branched and/or linear PI in the mixed solvent CH/AC at 25 °C. For comparable molar masses of the polymers the two-phase area is smallest for the branched PI and slightly larger for the linear PI; in the case of the unfractionated original sample of the branched polymer one observes a pronounced peninsula of immiscibility extending into the region of high CH concentrations. This feature is attributed to a large miscibility gap between the branched and the linear polymer, which was studied in more detail for the ternary system CH/branched PI/linear PI.

yearjournalcountryeditionlanguage
2007-10-01European Polymer Journal
https://doi.org/10.1016/j.eurpolymj.2007.08.002