The annealing treatment of drawn LCP nanocomposite monofilaments is discussed here. Upon annealing, an unstable structure is generated which presents a strong dependence on the annealing time sequence and temperature as observed by DSC. Moreover, it seems that increasing the draw down of the fiber restricts the formation of this new (unstable) structure. Based on dynamic mechanical analysis and on solid state C-13 NMR, the nature of the newly-formed structure is elucidated, and based on sequence ordering within the non-oriented amorphous phase in the copolymer, a 10% change in the monomer proportion in the ordered phase is observed after annealing. (C) 2010 Elsevier Ltd. All rights reserved.