INFLUENCE OF CRYSTALLINITY ON THE MORPHOLOGY OF POLY(ETHYLENE OXIDE) CONTAINING DIBLOCK COPOLYMERS

Low-molecular-weight poly(ethylene oxide)-polyalkane (PEG-PA) diblock copolymers have been examined between the order-disorder transition an d PEO melting temperature using small-angle neutron scattering (SANS), differential scanning calorimetry (DSC), and dynamic mechanical spect roscopy (DMS). Crystallization imposes layered ordering with polymer s tems oriented perpendicular, or tilted, relative to the microdomain in terface, thereby disrupting conventional amorphous microdomain morphol ogies. This effect can be used to switch the high symmetry bicontinuou s ordered G phase to lower symmetry cylinders or lamellae.