The first type includes acrylates, methacrylates,
bismaleimides etc., which increase the rate of cure. Most of them contain readily
accessible unsaturation without allylic hydrogens and therefore react only via addition
reactions. Examples of the second category are triallyl cyanurate (TAC), triallyl
isocyanurate (TAIC), triallyl phosphate (TAP), divinyl benzene (DVB) and also a small
amount of sulfur. Unlike the co-agents of the first category, most of the co-agents of the
second type contain both readily accessible vinyl unsaturation and sites for radical
addition and an ample amount of easily abstractable allylic hydrogens.