Thermal cross-linking of poly(vinyl methyl ether). II. Rheological behavior at the gel point

The rheological behavior of thermally activated cross-linking process of poly(vinyl methyl ether) was investigated. The viscoelastic material functions abruptly changed at the onset of cross-linking with different degree of sensitivity to the gel formation. The value of t_gel obtained from the coincidence of elastic storage modulus G′ and viscous loss modulus G″ was about 10 min longer than that determined from tan δ vs. t. The zero shear viscosity and the equilibrium shear modulus was also expressed in power law scaling function with the relative distance fro the gel point.