A theory of gel formation with terfunctional interunit junction

A theory related to the molecular size distribution and gel point in the polymerization by successive formation of terfunctional interunit junctions is presented. This type of polymerization may be realized in three‐dimensional networks containing isocyanuric and s‐triazine rings from polyisocyanate and polynitrile compounds, respectively. The gel point is obtained as αcrit equals; 1/2(f − 1), while in the polymerization due to bifunctional interunit junction it had been given by Flory and Stockmayer as αcrit equals; 1/(f − 1), where αcrit is the fraction of reacted groups at the gel point and f is the number of functional groups borne by a monomeric unit.