u‰‰ŽÒF ‘¾“c@—²•v Ž i‹ž“s‘åŠwŠî‘b•¨—ŠwŒ¤‹†Šj “úŽžF @‚P‚PŒŽ‚P‚X“úi‹àj@ŒßŒã‚SŽž‚R‚O•ª‚©‚ç êŠF ÂŽRŠw‰@‘åŠw@—HŠw•”i‘Š–ÍŒ´ƒLƒƒƒ“ƒpƒXj‚k“‚UŠK@‚k‚U‚O‚RŽº ‘è–ÚFuƒ~ƒNƒ‘Š•ª—£\‘¢‚Ì“]ˆÚƒLƒlƒeƒbƒNƒXv —vŽ|F Diblock copolymers have been studied for many years with tremendous scientific interest due to their ability to self-assemble into various ordered microstructures. The equilibrium morphological behaviors are now well understood. Recently kinetics of transitions in microphase separated states have been investigated experimentally. However, the theoretical study is less intensive. We study morphological transitions between microphase separated structures in diblock copolymers. By means of the two-mode approximation, kinetics of order-disorder and order-order transitions in the weak segregation limit are investigated by solving numerically a coupled set of the amplitude equations for the fundamental modes. Break-up and reconnection of domains during the morphological transitions are explored in detail. Furthermore, we identify the metastable or unstable intermediate structures which appear in the process of transitions. K. Yamada, M. Nonomura and T. Ohta, Macromolecules 37, 5762-5777 (2004). --------------------------------- ‹¤ÃF@ÂŽRŠw‰@‘åŠw@‚Q‚P¢‹ICOEƒvƒƒOƒ‰ƒ€