Reversible alternating polycondensation with

The reversible alternating polycondensation with FSSEs in both monomers (see Section 3.1.5), disregarding exchange reactions, is a convenient case study for discussing problems of modeling this kind of systems. It can be described by the rate laws of Eqs. (132) and (133). 

Prediction of molecular weight distributions for reversible, linear, alternating polycondensation is discussed in Section 3.4.5. Mathematical difficulties grow considerably in the presence of SSSEs. There seems to be no alternative to Monte Carlo methods for dealing with reversible nonlinear polycondensations or even linear polycondensations where more than two kinds of bonds are present. 

As pointed out in Section 11,1, polycondensation of sugars in aqueous acid is a reversible process made inefficient by the presence of water. Polycondensation can be conducted more efficiently in anhydrous solvents, with the removal of the evolved water. Alternatively, it may be carried out by using derivatives which possess at C-l nonhydroxylic substituents that, on displacement, may be conveniently removed from the reaction system. These methods will be discussed in turn. 

---