The second newtonian viscosity number

摘要: The second Newtonian viscosities η2 of solutions polystyrene and polyisobutylene were determined in a coaxial cylinder viscometer at shear rates near 105 sec.−1. viscosity numbers (η2 — ηs)/ηsc, where ηs is solvent c polymer concentration, as function concentration. For species viscosity-average molecular weight appears almost identical to intrinsic [η]. Above Mv ⋍ 1 × 106, plateau constant η2)/ηsc found when this plotted against c. good solvents the value: {(η2 ηs)/ηsc}p lies below [η], but poor (near θ temperature) opposite true. Correlation values vs. can be achieved manner Mark-Houwink equation: [η] = K′Mva, by writing: K″Mvb. sum + b any two given approximately unity. Though data are inconclusive, it that even above number tends approach approaches zero.