芳杂环二腈及其聚合物——Ⅵ.含5-氰基苯并噻唑环的二腈的合成及聚合

合成了下列三个含5-氰基苯并噻唑环的二腈:研究了它们的聚合反应并测定了所得聚合物的热氧化稳定性,结果表明皆与其结构相类似的含6-氰基苯并噻唑环的二腈相似。

THE AROMATIC AND HETEROCYCLIC DINITRILES ANDTHEIR POLYMERS——Ⅵ. THE SYNTHESIS AND POLYMEEIZATION OF THE DINITNLES WITH5-CYANOBENZOTHIAZOLE EING

In order to determine the influence of the different position of the cyano group in the dinitrile with benzothiazole ring upon the polymerization rate and the oxidative thermal stability of the polymers and to ascertain the excellent oxidative thermal stability of the polymers from the dinitrles with the benzothiazole ring, the dinitriles Ⅰ-Ⅲ with 5-cyano-benthiazole ring were synthesized by the following routes: The polymerization of these dinitriles was investigated. The polymerization rate of the dinitriles Ⅰ and Ⅱ was similar to that of their 6-cyano analogues IX and X. Theinfra-red spectrum of the polymers from Ⅰ - Ⅲ showed a s-triazine structure with the characteristic absorption at the region of 1510, 1360 and 820cm-1 and the disappearance of the nitrile absorption at ca. 2230cm-1.The isothermal weight loss at 371℃ in air during 200 hours of the polymers from these dinitriles was measured and compared with that of the polymers from dinitriles Ⅸ and Ⅹ. The results indicated that the weight losses were all low and similar of that of the polymers from Ⅸ and Ⅹ.From the above results, we can conclude that the different position of the cyano group, whether at 5-or 6-position, has no influence upon the polymerization rate and the polymers from all these dinitriles with 5-or 6-cyanobenzothiazole ring possess excellent oxi-dative thermal stability.