Reactions of amines with epoxide group. II. Kinetics of reaction of N,N'-disubstituted aromatic diamines with p-tolyl glycidyl ether

Mechanism and kinetics of curing of epoxides based on diglycidylamine with aromatic amines. 1. The reaction of diglycidylaniline with secondary amines

“…On the contrary, Grenier-Loustalot et al35 mention a lower reactivity of the second epoxy group in DGA after the first one has reacted, i.e., the negative substitution effect. This 4) isomers M"; (5)(6)(7)(8) isomers Ds. Experimental conditions: gradient elution, methanol-water starting with 55% and ending with 10% water.…”

“…From the dependence of the initial rate v0 on the initial concentration (toluene solution) of one reaction component at constant concentration of the other component, partial reaction orders with respect to epoxide (e) and amine (0) were determined for the initial stage: e = 1.1 ± 0.2, 0 = 2.2 ± 0. The reaction of epoxide with amine (eq 4 and 5) is autocatalyzed by the arising products containing OH groups, and it can be described in terms of kinetic relations ( 6)- (8). Due to the different reactivity of isomers, the reactions of isomer I (E, -* M¡ -> D,) and isomer II (En -* Mn -» Dn) are considered separately, because a change in configuration during the reaction is not possible.…”

“…where [A], [E¡], [M¡], and [D¡] are molar concentrations of NMA, isomers of DGA, monoadduct, and diadduct, respectively. The index i stands for the individual isomers I, II; k a, k y, k2h and k4i are the rate constants of reactions (3) monoadduct M,; (4) monoadduct Mn; (5) diadduct D:; (6) diadduct Du; (7) ring C; (8) ring; (9) ethers.…”

“…The intercept on the y-axis and the slope of the dependence give the rate constants of the noncatalyzed and catalyzed reaction, k 2i and k2¡ respectively, for isomer i (Figure 3a). Similarly, the rate constants k'4i and k4i can be determined from the relation for the formation of diadduct (8) as an intercept on the y-axis and the slope of the linear dependence (d- 3b).…”

“…Etherification. In the reaction between DGA and NMA and with epoxide in excess etherification takes place and the formation of both linear and cyclic products was observed (Figure lb, chromatographic peaks [7][8][9][10][11]. The reaction begins after almost the whole amount of amine has been consumed, as illustrated by Figure 2b.…”