Measurements of N1-N2 and eta in Steady Shear Flow and eta', eta'', andBirefringence in Small-Strain Oscillatory Shear for the Polyisobutylene Solution M1

摘要

Steady shear flow Stressmeter data for N1 - N2 and shear stress sigma near 20 Cfor increasing and decreasing values of shear rate gamma in the range 14-427/s exhibit hysteresis and evidence of polymer degradation; N1 and N2 denote the first and second normal stress differences in steady shear flow. Comparison with BASF cone-plate data for N1 shows tha t N2/N1 lines in the range from -0.1 to -0.2. Values of eta' at temperatures in the range 0-40 C and values of angular frequency omega in the range 1-3600/s obtained with c coaxial cylinder rheometer in which the inner cylinder oscillates along its axis, give satisfactory time-temperature superposition; values of eta , however, show small but significant deviations from time-temperature superposition; The curves eta sub r (gamma sub