| Research Abstract |
A novel class of polymers containing disiloxane, oligosiloxane, and polysiloxane as pendant groups were designed and synthesized. In order to develop the method to analyze the molecular mobility of these polymers, spin-lattice and spin-spin relaxations were investigated by solid state ^<29>Si NMR spectroscopy, It was found that the molecular mobility of these polymers were strongly dependent on the relaxation of silicon atoms in their side chain.
Investigation was also made on the controlled synthesis of silicon containing polymers, such as polysiloxanes, polycarbosilanes, and polysilanes, with definite stereochemistry of silicon atoms. Optically active allylsilane and vinyIhydrodisiloxane were synthesized from optically active menthyloxysilane derivatives. Polyaddition reactions of these monomers gave isotactic polycarbosilane and optically active and isotactic polycarbosiloxane whose isotacticities reflected the optical purity of the starting monomers. The tacticity was analyzed by ^1 H and ^<13> C NMR spectroscopies. Five-membered cyclic carbosiloxane was also obtained as a by-product in the polyaddition of the vinylsiloxane. Ring-opening polymerization of the cyclic carbosiloxane gave highly optically active and isotactic polycarbosiloxane of high molecular weight. Optically active disiloxane derivative, which is expected to be used as a starting monomer to obtain stereoregular polysiloxane which had not been synthesized before, was also synthesized from an optically active chIorosilane and an optically active silanolate. Its optical purity could be analyzed by HPLC on an optically active stationary phase.
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