| 초록 |
Morphological structures of binary blends of asymmetric poly(styrene)-poly(methyl methacrylate) diblock copolymers (PS-b-PMMA) of similar molecular weight but differing compositions are studied by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The compositions of styrene block, fPS, are roughly 0.7 in one block copolymer and 0.3 in a second block copolymer, respectively. From SAXS and TEM result, PS-b-PMMA having fPS=0.7 exhibits the cylindrical PMMA microdomains embedded in PS matrix and its inverse cylindrical phase is observed for PS-b-PMMA with fPS=0.3. The binary blends of two complementary PS-b-PMMAs are prepared at the various blend ratios using solution-cast process. When blend ratio is equal to 0.5 the mixtures show single microdomain of alternating lamellar structure without macrophase separation. In addition, various morphologies such as cylinder or sphere is also observed by changing blend ratio of two complementary diblock copolymers having complementary block composition and similar molecular weight can be utilized in obtaining various single microdomain without macrophase separation. |
