Molecular aggregation state of ultrathin polar polymer films

Ken Kojio, Mutsuhisa Furukawa

Research output: Contribution to conferencePaperpeer-review


Polyurethane (PU) is one of the most important polar polymers. This strong polarity might affect the aggregation structure for the PU ultrathin films because the effect of surface and interface of the ultrathin films is quite effective with decreasing film thickness. In this study, we investigated the relationship between aggregation structure and film thickness using atomic force microscope (AFM) and Fourier transform infrared (FT-IR) spectroscopy. The PU was synthesized with poly(oxytetramethylene) glycol (PTMG), 4,4'-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BD) by a prepolymer method. The PU ultrathin films were prepared onto a hydrophilic silicon wafer from the PU tetrahydrofuran solution by a spin coating method. Microphase-separated structure was clearly observed for all PU films, which the hard segment domains were surrounded by the soft segment matrix. For the thick film (>200 nm), the size of the hard segment domains was ca. 20 nm. This is almost same as bulk one. On the other hand, the domain size for the thin film with 8 nm thickness was ca. 10 nm. This seems to be simply related to a decreasing space. For the first time, we successfully obtained the experimental data, which the phase-separated domain size decreased with decreasing film thickness.

Original languageEnglish
Number of pages3
Publication statusPublished - Oct 18 2006
Externally publishedYes
Event55th SPSJ Annual Meeting - Nagoya, Japan
Duration: May 24 2006May 26 2006


Other55th SPSJ Annual Meeting

All Science Journal Classification (ASJC) codes

  • Engineering(all)


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