Effect of the structure of photosensitive groups contained in novel PU-type polymeric benzophenone photoinitiators on photopolymerization

摘要

Three polymeric photoinitiators, PUSBA-s, PUSBA-o and PUSBA-c, were synthesized through polycondensation of TDI, different photosensitive diamines, and BDEA. UV/Vis spectra indicate that the maximum absorption depends mainly on the structure of the photosensitive groups. ESR spectra show that PUSBA-s can efficiently generate free radicals. The photopolymerization of TMPTA and a PU prepolymer, initiated by these polymeric photoinitiators, was studied by photo-DSC. The results indicate that the structure of the photosensitive groups has an important effect on photopolymerization: PUSBA-s is the most efficient and PUSBA-c is the least efficient of the three polymeric photoinitiators.