Inversion of Phase Morphology in Polymer-Blend Thin Films on Glass Substrates

✍ Scribed by Qi Zong; Zhi Li; Xuming Xie

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 500 KB
• Volume: 205
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200300235

✦ Synopsis

Abstract

Summary: The phase‐morphology inversion in two blend systems of polystyrene/poly(methyl methacrylate) (PS/PMMA) and polystyrene/poly(ε‐caprolactone) (PS/PCL) has been studied after their thin films were prepared on glass substrates by spin‐coating from a co‐solvent tetrahydrofuran (THF). Phase‐contrast microscopy (PCM), scanning‐electron microscopy (SEM) equipped with energy dispersive X‐ray spectroscopy (EDS), and atomic force microscopy (AFM) were used to obtain information on the morphology of the thin films during heat treatment. It was found that the PMMA‐rich and PCL‐rich phases are always continuous after annealing in either of the PS/PMMA and PS/PCL blend thin films, even though the PMMA and PCL are minor components in the blends. This should result from the better wetting abilities of PMMA and PCL on a glass substrate than PS in the blends. The effect of the viscosity in the evolution of the phase structure was also investigated by changing the molecular weight of PS in the PS/PCL blend thin films. Further more, it is found that the phase‐separation process and the wetting phenomenon of the blends on the glass substrate can be strongly suppressed after adding PS‐block‐PMMA diblock copolymer to the PS/PMMA blend system as a compatibilizer.

Scheme of the longitudinal section of the evolution of the phase structure of a PS:PMMA (70:30 w:w) blend film.

imageScheme of the longitudinal section of the evolution of the phase structure of a PS:PMMA (70:30 w:w) blend film.