Viscoelastic characterization of corn starch paste: (II) The first normal stress difference of a cross-linked waxy corn starch paste

Abstract The power-law strain model used to characterize the first normal stress difference ( N 1 ) was checked here second based on the experimental linear viscoelastic properties, steady shear viscosities, and N 1 s of two cross-linked waxy corn starch pastes reported in 2003. Parameter f in a structured integral viscoelastic constitutive equation was obtained using the viscosities in the dynamic and steady shear experiments, and both the original and power-law strain models were employed to describe the normal component in the strain matrix of the equation and the N 1 s of the two pastes. The results showed that the three types of viscoelastic properties of the paste can be described well by the structured equation including the power-law strain model. In contrast, the descriptions of N 1 s based on the original strain model have huge deviation from the experiments for both pastes, which are similar to the first characterization of N 1 of corn starch paste with sucrose in 2022.