| 초록 |
Phase behavior of binary blends consisting of high molecular weight (HMW) polystyrene-b-poly(2-vinyl pyridine) copolymer(S2VP) & LMW polystyrene-b-poly(4-hydroxystyrene) copolymer(SHS) was investigated by using SAXS and TEM. Both S2VP & SHS exhibited lamellar. When the amount of SHS in blends was small, lamellar are maintained. In this situation, shorter PS & PHS chains in SHS are located at longer PS & P2VP chains, respectively. However, with increasing amount of SHS, these are transformed to cylindrical, and spherical. This is attributed to hydrogen bonding between P2VP & PHS, which increases the effective volume of PHS/P2VP phase because some of SHS chains could be dissolved into P2VP domains. On the other hand, when a relatively HMW of SHS was used, spherical were not observed even at a large weight fraction of SHS in the blend. In this situation, P2VP phase should not be increased significantly because of large enthalpic loss between PS/P2VP. |
