Naphthalimide-and Methacrylate-Functionalized Polysiloxanes: Visible-Light Photoinitiators, Modifiers for Polyurethane Acrylate and Photocurable Coatings

Employing “green chemistry” photopolymerization techniques, a series of multifunctionalized macrophotoinitiators (SND-MAs) containing naphthalimide (ND), methacrylate (MA) and polysiloxane were successfully prepared. The introduction of methacrylate enhances their compatibility with acrylate monomers and resins. SND-MAs showed very good photoinitiating properties in the presence or absence of hydrogen donors. The migration study demonstrates that SND-MAs possess excellent migration stability. In particular, the mass fractions of the extracted SND-MA-I-3 and SND-MA-I-4 in the cured 1,6-hexanediol diacrylate (HDDA) polymer are as low as 0.082 % and 0.054 %, respectively. More importantly, the use of SND-MAs as initiators brings about desirable modifications to the cured materials, such as an improved resistance against water and ethanol as well as improved thermal stability. Moreover, the series of SND-MA-Is exhibit good self-forming properties. Their self-forming films show excellent thermal properties, hardness and hydrophobicity. Thus, SND-MAs could be used as photoinitiators, modifiers and coatings at the same time.