| Budget Amount *help |
¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥600,000 (Direct Cost: ¥600,000)
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| Research Abstract |
The well-defined side-chain structure of dendrimers is expected to play an important role on the permselectivity for highly selective membranes. We synthesized dendritic phenylacetylene monomers containing tert-butyl group, trimethylsilyl group, or oligodimethylsiloxane, as the peripheral group using the convergent approach. The monomers were polymerized with rhodium catalyst at the terminal acetylene unit to yield the corresponding poly(phenylacetylene) derivatives as yellow powders with a high degree of polymerization, e.g., DP=2.8 x 10^3, in spite of their steric bulkiness. Some reasons why the monodendrons gave the polydendrons with high molecular weight in spite of their steric bulkiness were probably considered as follows. The terminal acetylene was exposed from dendritic crowd, and the polymerization proceeded stereoregularly to give the reasonable packing of the side-chain dendrons. The polymers were soluble in common organic solvents, such as chloroform and tetrahydrofuran, but insoluble in alcohols, and the solubility of these polydendrons was better than that of the corresponding zero generation poly(phenylacetylene) derivatives. The wide angle X-ray scattering of the polymers suggested the pseudohexagonal lattice of rod-like molecules. The interplanar d spacing increased with increasing generation or size of the peripheral silyl group. The polydendrons indicated good membrane forming ability, and the gas permeability of the membrane was examined. The oxygen permselectivity of the polydendrons showed good performance in comparison with the corresponding zero generation of poly(phenylacetylene) derivatives. It was found that the well-defined dendritic and rod-like structure of the polydendrons was useful for pemselective membrane.
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