Statistical Treatment of Diamine-diepoxide Curing

The building blocks are represented diamine units with 0, 1, 2, 3 and 4 reacted hydrogens (diamine is tetrafunctional) and by diepoxide units with 0, 1 and 2 reacted epoxy groups. Originally, the distribution of fractions of these units was obtained by solving the complete set of differential equations (Eqs. (50-56) of Ref ), but this is unnecessary because of independent reactivities. It is sufficient to generate the distribution of monoamine and monoepoxide units, with respect to the number of bonds they issue from reaction kinetics and to obtain the distribution of diamine and diepoxide units, respectively, by convolution (cf. Fig. 7). 

According to Eqs. (30, 31), one can express the molar concentrations of primary, secondary, and tertiary amino groups, c, c, and c, respectively, by the following kinetic equations 

0 ureoctedj reacted functionalities ce ccMTversicMi of epoxy groups 

The dependence of ap, a and a, on conversion of amine hydrogens, a, is obtained by combination of Eqs. (37) and (38) with the balance equation 

The fraction of unreacted and reacted epoxy groups is just equal to 1 — and e, respectively, where is the conversion of epoxy groups. 

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