双氰胺固化环氧树脂的研究

<正> 双氰胺做为环氧树脂的固化剂,其贮存期可以达到一年以上,这种固化物的机械和介电性能优异,因此,广泛用于制造层压等电工材料方面。国外许多人都曾对双氰胺与环氧树脂的固化反应历程和固化物的性能做过研究,指出了在固化过程中化学结构的变化

A STUDY OF EPOXY RESINS CURED WITH DICYANDIAMIDE

Inflences of temperature and composition on the curing mechanism and the glass transition temperature (Tg) of the cured compound in benzyldimethylamine (BDMA) catalyzed-dicyan-diamide (DICY)-epoxy resins (DGEBA) system was studied by IR, DSC, dielectric and dynamic mechanical properties. The results indicated that the curing involved the addition reaction of amino groups with epoxy groups, besides the etherification of epoxy groups. The etherifica-tion as a competitive reaction was not favor both at 100℃ and 170℃.In addition,at 140℃or 170℃, the reaction of cyano groups with hydroxy groups aor epoxy groups gave rise to im-ino-ether bond, which then rearranged to the compound of acylamide bond. A higher Tg of cured compound network could be reached with a amine-to-epoxy ratio (a/e) of 0.6 in the same cured condition.