PHASE-SEPARATION IN PMMA SILICA SOL-GEL SYSTEMS

被引：70

作者：

SILVEIRA, KF ^{[1
]}

YOSHIDA, IVP ^{[1
]}

NUNES, SP ^{[1
]}

机构：

[1] UNIV CAMPINAS, INST CHEM, BR-13081 CAMPINAS, SP, BRAZIL

来源：

POLYMER | 1995年 / 36卷 / 07期

关键词：

PHASE SEPARATION; PMMA SILICA; SOL-GEL;

D O I：

10.1016/0032-3861(95)95921-M

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

The mechanism of phase separation of sol-gel alkoxy-derived silica systems obtained by acid catalysis in the presence of poly(methyl methacrylate) (PMMA) and tetrahydrofuran was investigated by light scattering. Spinodal decomposition (SD) was confirmed for systems with intermediate PMMA/alkoxy compositions occurring with a simultaneous viscosity increase. The initial stages of phase separation followed the linear theory proposed by Cahn. For systems with low PMMA content, a behaviour typical of nucleation and growth was detected. In this case gelation took place after demixing. The morphology of the final PMMA/silica hybrid material was investigated by scanning and transmission electron microscopy with element-specific analysis. A matrix/disperse domains morphology was also verified for systems which demixed by SD, indicating that phase coarsening occurs. A micellar/lamellar microstructure was observed inside the separated phases.

引用

页码：1425 / 1434

页数：10

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