Dynamic rheology of agar gels: theory and experiments. Part II: gelation behavior of agar sols and fitting of a theoretical rheological model

A theoretical rheological model for agar gels, based on the bead spring model for linear flexible random coils and the model for crosslinked polymers, is successfully fitted to experimental gelation curves obtained over a wide range of cooling rates (0.5–20 °C min−1) and agar concentration (1–3 wt%). The theoretical gelation temperature, Tgelmodel increases with increasing agar concentration and decreasing cooling rate. The intrinsic net association rate increases significantly with increasing cooling rate. This increase is related to the higher probability of association of the non-associated agar molecules at higher cooling rates.