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

Abstract

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.

Silicone-Thioxanthone: A Multifunctionalized Visible Light Photoinitiator with an Ability to Modify the Cured Polymers

“…In comparison to the initial photoinitiator quality, the mass fraction of the extracted photoinitiator is 8.1% for STX and 54.0% for TX-B. This big difference between them could be attributed to the differences in the molecular weight [9,10]. This indicates that STX could be used as an efficient one-component visible light photoinitiator with low extractability of the photoinitiator in the cured materials.…”

“…As an important component in the polymerization process, the photoinitiator or the photoinitiator system plays an important role in the polymerization process. Among these photoinitiators, polymeric [4], polymerizable [5,6,7,8,9,10,11,12] and one-component photoinitiators [13,14,15] have garnered much more attention in comparison to the conventional low molecular weight photoinitiators due to their low odor, non-yellowing, nontoxicity, low migration, and good compatibility with the formulation components [16,17].…”

“…Recently, we reported on a series of silicone-naphthalimide visible photoinitiator for free radical polymerization. They not only showed very good photoinitiating properties, but also brought about the desired modification to the cured-materials, such as improved resistance against water and ethanol, and better thermal stability [9,10].…”

Solvent-Dependent Photophysics and Reactivity of Monomeric and Dimeric 4-Amino-1,8-Naphthalimides

“…Though the intermediates were not directly observed, the mechanism of action is thought to involve reductive quenching of both the singlet and triplet excited states. 26,27 4-Aminosubstituted 1,8-naphthalimides have also been used in photochemical tissue bonding and cartilage repair. 28−32 The cross-linking of the RNase A was demonstrated using both a monomeric and dimeric 4-amino-substituted 1,8-naphthalimide.…”

High Efficiency and Low Migration Hyperbranched Silicone Contain Macrophotoinitiators for UV-Cured Transparent Coatings

“…For example, Xie prepared amphiphilic macrophotoinitiators with HMPP and it reveals that the photolysis rate of them was slightly lower than that of HMPP, but the migration rate of them from the UV-cured material was lower than that of HMPP [ 21 ]. In the past decades, many efforts have been paid to develop novel silicone macrophotoinitiators with HMPP because they not only possess low migration and odor, but also can effectively reduce the oxygen inhibition and improve properties of UV-cured materials [ 27 , 28 , 29 , 30 , 31 ]. A novel hydrosoluble photocleavage polysiloxane photoinitiator based on HMPP and aminopolysiloxane for preparing a gradient polymer shows relatively good solubility in water and excellent photoinitiating efficiency [ 23 ] and a photocleavage polymerizable organosilicon macromolecular photoinitiator based on HMPP exhibits the migration of photolysis fragments toward the cured material surface was mitigated significantly [ 24 ].…”