Poly(4-vinyl phenol)(PVPh) was neutralized by LiOH and PVPh ionomers(PVPh-Li) with different Li neutralization extents were synthesized. The variation in T_g with Li neutralization was determined by DSC and the results show that the T_gincreases by 3.8 ℃ per Li mol%. When comparing this result with the 3.2 ℃ per Na mol% reported for poly(styrene-co-hydroxy styrene), the greater value for PVPh-Li may be due to a strong interaction between unneutralized free -OH and -OLi produced. No distinct small angle X-ray scattering(SAXS) peak was observed for these PVPh ionomers in bulk. In the 50/50 blend of PVPh-Li with PVPh, the miscibile blend was obtained when the Li neutralization in PVPh-Li was 10 mol%. On the contrary, the 50/50 PVPh-Li/PMMA was immiscible when the Li neutralization was 5 mol%. It can be concluded that, even if the staring blend is miscible owing to hydrogen bonding, the miscibility of blend becomes diminished by introducing small amount of ion groups into one of the constituent polymers and the blend can be immiscible as long as any new strong intermolecular ion-dipole interaction is not generated.

폴리비닐페놀(PVPh)을 LiOH로 중화시켜 중화도가 다른 여러 종류의 PVPh 이오노머(PVPh-Li)를 제조하였다. 중화도에 따른 PVPh-Li의 T_g 변화를 DSC로 측정한 결과 Li mol% 당 3.8 ℃의 T_g 증가가 관찰되었으며 유사한 구조를 지닌 poly(styrene-co-hydroxy styrene)의 3.2 ℃ 증가에 비해 높은 수치이다. 이는 중화되지 않은 -OH가 -OLi와 강한 상호작용을 하기 때문인 것으로 생각되며, 이러한 상호작용으로 인해 -OLi 끼리의 클러스터 형성이 어려워져 소각X선산란 실험에서도 뚜렷한 피크가 관찰되지 않았다. 제조된 PVPh-Li를 PVPh와 블렌드시 50/50 조성의 경우 중화도가 10 mol%인 PVPh-Li와 혼

Keywords: PVPh/PMMA blend; PVPh ionomer; miscibility; hydrogen bonding; ion-dipole interaction