Photopolymerization quantum yields in two reactive diacetylenes, 3BCMU and 4BCMU, and relation to gamma-ray induced polymerization
Résumé
Photopolymerization initiation yields from neutral excited states eta(i) are measured; for 4BCMU, eta(i)approximate to 0.075, but this value is 200 times smaller for 3BCMU, although the gamma-ray reactivities of the two materials are similar. This difference is not related to different geometries of the reaction centre. It is proposed that it is due to different strengths of hydrogen bonds between side groups. The importance of ionic initiation under gamma-ray irradiation is discussed. (c) 2007 Elsevier B.V.. All rights reserved.