Properties and curing kinetic of diglycidyl ether of bisphenol a cured with a phosphorus-containing diamine

摘要

Diglycidyl ether of bisphenol A (DGEBA) was cured with a new phosphorus-containing diamine, 1,4-bis(3-aminobenzoyloxy)-2-(6-oxido-6H-dibenz [Left Angle Bracket] c,e [Right Angle Bracket] [Left Angle Bracket] 1,2 [Right Angle Bracket] oxaphosphorin-6-yl)phenylene II, which was derived from 2-(6-oxido-6H-dibenz [Left Angle Bracket] c,e [Right Angle Bracket] [Left Angle Bracket] 1,2 [Right Angle Bracket] - oxaphosphorin-6-yl)-1,4-dihydroxy phenylene and 3-nitrobenzoyl chloride followed by hydrogenation. The structure of the synthesized phosphorus-containing curing agent II was confirmed through EA, IR, 1H-NMR, and ~(31)P-NMR. The curing kinetics of the DGEBA/II system were studied by the dynamic and isothermal DSC method. Dynamic kinetic parameters were calculated by using the Kissinger and Ozawa's methods, respectively. Isothermal kinetic parameters, including k_1, k_2, m, and n, were determined by an autocatalytic mechanism proposed by Kamal. The model gives a good description of curing kinetics up to the onset of vitrification. The glass transition temperatures of cured epoxy (DGEBA/II) were 180°C based on DMA and 170°C by DSC, respectively. The onset decomposition temperatures (T_d onset) were 376 and 367°C under nitrogen and air, respectively. Char yields at 700°C were 38 and 18% under nitrogen and air, respectively. Limiting oxygen index (LOI) was 30, thus the phosphorus-containing diamine curing agent II was found to impart flame retardancy to the cured epoxy resin.