Structure, dependence stoichiometric network

Figure 3. Dependence of the structure factors A, Ae, and As on the stoichiometric network chain concentrations.

One way to generate networks with dangling ends in this A + Bj type of reaction is by preparing formulations with an initial stoichiometric imbalance (r). In this case the amount of pendant chains present in the network at the end of the reaction depends on r (Figure 1). There exists two principal disadvantages in these kind of systems first, it is impossible to vary the amount and molecular weight of the pendant chains independently and second, the resultant pendant chains may have complex structures with wide polydispersity and branching that arc not very suitable for structural studies [10,13]. 

This polymer may potentially have a high density of cross-links since the average valence of the prepolymeric stoichiometric mixture glycerol/phthalic anhydride is equal to 2.4. However, due to the inaccessibility of a fraction of reactive sites, it is extremely difficult to reach such an ideal structure, and the true cross-link density of the network thus depends on the stoichiometric balance and on the reaction conditions. 

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