Rheological property of cross-linked carboxymethyl modified corn starch

The rheological property of starch pastes is an important influencing factor of product quality of starch industry.The rheological properties of the corn starch and the cross-linked carboxymethyl modified starch were studied under different shear rate and temperature.Results indicate that starch pastes exhibits aspseudoplastic fluid and the shear-thinning characteristics.At the same temperature,the shear stress was higher when the shear rate increased;At the same shear velocity,the apparent viscosity was higher while the modification increased,was reduced while the shear stress and temperature increased.The viscous coefficient of the starch was higher while the modification increased,was reduced while the temperature increased.The rheological indexes of the starch was reduced while the modification and the temperature increased.The flow energy increases while the modification increased.The thermostability of the cross-linked carboxymethyl modified starch was markedly increased.Rheological model was τ =105.6γ0.3599 under normal temperature if viscosity was represented by τ,and shearing velocity by γ,and R2=0.9882.The influence of temperature on viscosity coefficient and rheology exponent can be accurately described by Arrhenius equations k=0.2049 e-19379/R(T+273.2) and R2=0.9748.