A general equation in polycondensation

In polycondensation, we define F and f to be the true and effective average functionalities of the reaction system, respectively. The value of Q relates to the functionality and quantity of the nonbifunctional monomer. If there is monofunctional monomer in the reaction system, the value of Q may be less than 0. If the ring-closure reaction in a system can be neglected, the relation among the molecular weight, the component of the reaction system, and the reaction extent of functional groups can be represented by the following equation: P = (F − Q − 2/xn)/f. The equation may be used in line, branching, and cross-linking polycon-densations without any restrictional conditions. According to Carothers, the gelation point Pc can be estimated by the following equation: Pc = (F − Q)/f. All relations among the molecular weight of the polymer, the component of the reaction system, and the reaction extent of the functional group can be replaced by the new equation. Only the Flory equation that is used to estimate Pc cannot be replaced by the new equation.