Dynamic behavior and phase separation sensitive to temperature of a series of polyacrylic gels were studied by dynamic light scattering. The dynamic behavior of the gels is characterized in terms of the correlation length ξ and diffusion coefficient D. The rules of the influence of cross-linking degree

concentration of polymer and amount of initiator on and D were obtained. When cross-linking degree increases

decreases and D increases

respectively

and there are different scaling relationships under lower or higher cross-linking degree. There is also a scaling relationship between the diffusion coefficient and the concentration of polymer. The higher the concentration

the larger the diffusion coefficient.When the amount of initiator increases

ξtends to be small. And the rules of the phase separation sensitive to temperature for the gels are as follows. When temperature increasesgradually the cooperation diffusion coefficient D increases

the mesh size ξdecreases

the distribution of ξtends to narrow. When temperature decreases gradually

the solvent gets poorer

so phase separation takes places for Х-induced microsyneresis

thus turbidity of the gel appears. Furthermore

the higher the degree of cross-linking

the higher the temperature of phase separation.