Leibler’s mean-field theory

The previously discussed theories were developed for monodisperse diblock copolymers, which are not TPEs. However, Leibler s mean-field theory has been extended to include polydispersity (Leibler and Benoit, 1981) and to include triblock, star, and graft copolymers (Olvera de la Cruz and Sanchez, 1986 Mayes and Olvera de la Cruz, 1989). In the former case, polydispersity corrections tend to lower x N corresponding to the ODT. As would be expected from the analogy between blends and diblocks, triblocks will phase separate at higher xN values than the corresponding diblocks. This theory predicts a monotonic increase in the critical value of x A as the symmetry of the triblock increases, to a maximum of about 18 for the symmetric triblock. Surprisingly, the minimum xN value that separates the order and disordered regions in triblocks does not necessarily correspond to the critical point. 

The order-disorder transition (ODT) of block copolymers has been extensively investigated [1, 2] since Leibler s mean-field theory [4], where the effects of con-... 

---