Curing Agents, Cure Accelerators, Crosslinkers XL

Curing agents are intentional additives and are used to crosslink resinous systems to improve bulk properties, and ultimately to reach the thermoset state. For under-cure of the system or excess application of curing agents, so that some of the curing agents remain, migration of these chemicals (which are toxic to different extents) may occur. 

For plastics and rubbers, and specifically for unsaturated polyesters, peroxides are used as crosslinkers e.g., benzoyl peroxide (BPO) at high temperatures and methyl 

Sometimes curing agents, antioxidants and accelerators can interact, creating new toxic chemicals e.g., when guanidine accelerators are used during the vulcanisation of rubber with sulfur with phenylene diamine-based antioxidants, aromatic amines and isothiocyanates can be produced, both of which are suspected carcinogenic agents [11]. 

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