Studies of the polymerization of diallyl compounds. XLI. Discussion of substantially identical gel points among three isomeric diallyl phthalates

In the bulk polymerization of three isomeric diallyl phthalates, diallyl phthalate (DAP), diallyl isophthalate, and diallyl terephthalate (DAT), no difference in the actual gel point was substantially observed. This interesting gelation behavior is discussed in terms of the correlation between gelation and the difference in cyclization modes, and the difference in reactivity between the uncyclized and cyclized radicals for crosslinking; the nonconsecutive addition in DAT polymerization led to a delayed gelation and the cyclized radical in DAP polymerization showed an enhanced reactivity for crosslinking.