Dilute-solution properties of trans-1,4-polyisoprene

Trans-1,4-polyisoprene was fractionated by both fractional precipitation and preparative gel permeation chromatography to obtain possibly sharp fractions of narrow molecular weight distribution. Selected fractions were characterized by light scattering, viscosity, and gel permeation chromatography. Necessary corrections for molecular heterogeneity were applied. Some of the characteristic relations between η] and M _w are η] = 1.81 × 10^?4 M in benzene at 30°C, η] = 1.38 × 10^?4 M in n-hexane at 30°C, which are found to be in good agreement with literature data when corrected for molecular heterogeneity.