The ternary hybrid systems of PVA/APP/LDH were prepared through addition of flame retardant, ammonium polyphosphate (APP), and flame-retardant synergist, layered double hydroxide (LDH) so as to improve flame retardancy of PVA. The rheological behaviors of flame-retardant PVA/APP/LDH hybrid systems were investigated using parallel-plate rheometer. The shear-thinning phenomenon occurred in the hybrid systems within the whole frequency range studied. When the concentration of PVA in aqueous solution was 9% and its proportion was 85wt% in the PVA/APP/LDH system, the complex viscosity of the hybrid systems increased first and then decreased as the proportion of LDH increased from 1wt% to 3wt%. According to the analysis of the rheological parameters and plots including the storage(G’) and loss modulus(G”), dynamic loss tangent (tan δ), Cole-Cole plot, relaxing time, etc, it can be concluded that the viscous rather than elastic rheological behavior is dominant, namely G”> G’ and tan δ>1. Thereby, the rheological behaviors of PVA/APP/LDH system were more complicated than PVA and PVA/APP systems.
