Methods of calculation of the critical conversion in the formation of cross-linked polymers

Mathematical methods of calculation of the critical conversion (gel point) in the formation of crosslinked polymers by polycondensation, cross-linking of macromolecules and three-dimensional polymerisation are considered. The results obtained using the statistical approach (<<ideal>> polycondensation), the concept of blocks (non-ideal polycondensation) and kinetic calculations that allowed determination of the gel point in three-dimensional polymerisation processes are discussed.