Glass Transition Versus Microphase Separation: a Phenomenological Replica-Field Theory for AB Copolymer Systems

We present a phenomenological replica-field theory for symmetric AB copolymer systems with the A.block near its glass transition point. Using a variational principle based on the second Legendre transformation we prove that the interaction between composition fluctuations, due to the loss mobility of the A monomers, results in the elimination of microphase separation. Instead of a microphase separation there is a third-order phase transition between the homogeneous state and a glass-like state with broken replica symmetry of the two-replica density-density correlation function. We show that near the point of the glass transition tworeplica correlation function Qoefl(q) is proportional to trie square of the one-replica correlation function QoeflG$~(q), where Qoefl is a matrix describing trie metric properties of trie replica