The physical system we consider here is an interpenetrating polymer network made of two chemically incompatible cyclic polymers A and B, linked each to other by topological trapping. When the system is cooled down, below some critical temperature, the system undergoes a microphase separation. The latter results from a competition between the usual macrophase separation and the fact that the cyclic polymer chains are connected. Using an extended de Gennes theory, we first compute the static structure factor allowing the study of the static critical properties of such a transition. We show that this structure factor exhibits a maximum at some finite value of the wave-vector, qc*, of which the inverse, =qc*-1, measures the size of microdomains. Second, we complete the study by kinetics of this microphase separation when the temperature of the system is lowered from an initial value towards a final one very close to the spinodal point. This kinetics is investigated through the relaxation rate, τC (q), that can be interpreted as the necessary time to form microdomains of size q−1, where q is the module of the wave-vector q. In particular, we find that, at small scales compared to the mesh size , that is for q−1 << , the characteristic frequency, ΩC (q) = τC−1(q), behaves according to: ΩC (q) ~ q6, with a known amplitude. The obtained results must be compared to those relatively to the well-studied crosslinked polymer blends composed of connected linear chains. The main conclusion is that, the closed topology of connected polymer chains induces a drastic change of the critical behavior in comparison with the crosslinked systems.