Session D40 - Poster Session I.
POSTER session, Monday afternoon, March 12
Exhibit Hall, Washington State Convention Center
The morphology and crystallization behavior of a symmetric crystalline / crystalline block copolymer: poly(ethylene-b- ethylene oxide) (P(E-b-EO)) under different thermal conditions was studied. The diblock copolymer was found to have an alternating lamellar morphology in both molten and solid state. Both polyethylene and poly(ethylene oxide) crystalline chains were found to orient normal to the interface of microphase separated domains by TEM and electron diffraction. Crystallization of polyethylene block resulted in a significant increase (~4nm) of lamellar spacing while the subsequent crystallization of poly(ethylene oxide) block caused little variation. Although such a dramatic change in lamellar spacing were observed upon crystallization, the block copolymer lamellar grain structure was maintained as observed by TEM and optical microscopy indicating that the pre-existing microphase separated morphology acted as a template for crystallization. The crystallization characteristics of poly(ethylene oxide) inside the hardened polyethylene domain of P(E-b-EO) were compared with its unhydrogenated counterparts: poly(butadiene-b-(ethylene oxide)) where the other block is amorphous and flexible.