Factors affecting the photoyellowing which occurs during the photoinitiated polymerization of acrylates

The influence of the type of photoinitiator, type of polymerizable reactive diluent and added amine synergist on the yellowing which occurs during the curing of clear films is examined. Type I photoinitiators based on acetophenone give rise to the least yellowing. The presence of amines, such as N-methyldiethanolamine, increases yellowing to a noticeable extent. Amino groups present in the initiator or the reactive diluent lead to marked yellowing. The chemistry responsible for the yellowing is explored.

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