| Abstract
| - Dynamics, structure, and domain size in polyimide−poly(dimethylsiloxane) networks (PI−PSX) with various compositions were investigated by solid-state NMR spectroscopy. 29Si and 13C MASNMR spectroscopy revealed the presence of PSX chains in two motional states, and their relative contentwas estimated. The overall mobility as well as local motions was studied by 1D and 2D 1H wide-linespectroscopy. 2D WISE spectra proved large differences in molecular mobility of PSX and PI chains.High mobility of PSX is not imparted to rigid PI, and the interfacial region is located in the PSX phase.This region corresponds to the immobilized PSX chains at the surface of PSX domains, which link PIchains. The spherical morphology and domain sizes at the nanometer scale were determined from analysisof spin diffusion processes. Molecular mechanics and dynamics calculations were performed to designPSX domains at the atomic level. Correlation of the structure and morphology with mechanical andthermal properties is discussed.
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