Preparation of polysiloxane optical resolution membranes containing high-density chiral spaces by using sol-gel method

有些硅乙炔聚合物具有庞大的手性品尼基，显示出良好的对映选择性渗透性。我们认为这种选择性是由r -异构体和s -异构体之间的扩散率差异引起的，通过几个大的品尼基包围的“高密度手性空间”。然而，由于手性空间非常小，大体积的品尼尼基团的迁移率很低，因此渗透率很低。通过在膜聚合物中引入“聚硅氧烷”单元，这个问题得到了解决。通过“溶胶-凝胶法”或烷基硅氧基水解对膜进行直接改性使膜非常脆，因此这些膜不能用于分离膜。因此，在不影响其他结构的情况下对膜进行修饰是很重要的。综上所述，我们得到了以下三个结论。1)“高密度手性空间”对于高对映体选择性非常重要。2)聚硅氧烷具有增强透气性的效果。3)“溶胶-凝胶法”必须更精确地控制，以保持膜的强度。

Some silylacetylene polymers having bulky chiral pinanyl groups were found to show good enantioselective permeabilities. We thought that the permselectivity was caused by the difference of diffusivity between R-isomer and S-isomer through "high-density chiral spaces" surrounding by the several bulky pinanyl groups. However, since the chiral spaces were very small and the mobility of bulky pinanyl groups was low, permeation rates were pretty low. This problem was solved by introducing "polysiloxane" units into membrane polymers. Direct modification of membranes by "sol-gel method" or hydrolysis of alkylsiloxy groups made membranes very brittle, and as a result these membranes were not able to be used for separation membranes. Therefore, it is important to modify the membranes without affecting other structures.In summary, we obtained the following three conclusions.1)"High-density chiral spaces" is very important for high enantioselectivity.2) "Polysiloxane" is effective for enhancing permeability.3) "Sol-gel method" has to be controlled more precisely to maintain membrane strength.