Synthesis of Polyisocyanurates by Thermal Rearrangement of Polycyanurates

摘要

Polyisocyanurates have been successfully prepared by the thermal rearrangement of polycyanurates, which were obtained from 2,4-dichloro-6-methoxy-1,3,5-triazine and bisphenol monomers. The thermal rearrangement was carried out in the presence of a small amount of tetrabutylammonium bromide (TBAB) as a catalyst at 200 degrees C for 30 or 60 min in an argon atmosphere, and the degree of arrangement was greater than 95%. Transparent and amorphous polyisocyanurate films were obtained and showed a good thermal stability with a 5% weight loss temperature above 340 degrees C in nitrogen and the glass transition temperature above 210 degrees C. Films with a 10-mu m thickness exhibited an excellent transparency above 90% at 400 nm. Furthermore, the thermal rearrangement of 2,6-bis(4-methoxyphenyl)-6-methoxy-1,3,5-triazine to 1,3-bis(4-methoxyphenyl)-5-methyl-1,3,5-triazinane-2,4,6-trione was investigated in detail. It was found that the complete thermal rearrangement was successfully accomplished in the presence of 2 wt % TBAB at 150 degrees C for 20 min in an argon atmosphere. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 692-698