Abstract

In this work, we presented a new bimolecular photoinitiating system based on 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives as visible photosensitizers of diphenyliodonium salt. Real-time FTIR and photo-DSC photopolymerization experiments with a cycloaliphatic epoxide and vinyl monomers showed surprisingly good reactivity of the bimolecular photoinitiating systems under UV-A, as well as under visible light sources. Steady-state photolysis, fluorescence experiments, theoretical calculations of molecular orbitals, and electrochemical analysis demonstrated photo-redox behavior as well as the ability to form initiating species via photo-reduction or photo-oxidation pathways, respectively. Therefore, the 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives were also investigated as a type II free-radical photoinitiator with amine. It was confirmed that the 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives, in combination with different types of additives, e.g., amine as a co-initiator or the presence of onium salt, can act as bimolecular photoinitiating systems for cationic, free-radical, and thiol-ene photopolymerization processes by hydrogen abstraction and/or electron transfer reactions stimulated by either near-UV or visible light irradiation. Finally, the 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives were selected for 3D printing rapid prototyping experiments. Test objects were successfully printed using purely cationic photosensitive resin, created on a 3D printer with a visible LED light source.

Highlights

  • Three-dimensional printing is a technique used for the quick fabrication of three-dimensional objects based on virtual CAD documentation

  • We proposed in this potentials were examined as components of visible light photoinitiating systems for different types paper the use of novel 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives with an electron-donating of photopolymerization processes

  • These 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives group incorporated into this structure moiety that will further increase the efficiency of sensitization

Read more

Summary

Introduction

Three-dimensional printing is a technique used for the quick fabrication of three-dimensional objects based on virtual CAD documentation. The new compounds with better spectroscopic properties and lower oxidation of sensitizers, which results in less negative values (∆GET ) For this purpose, we proposed in this potentials were examined as components of visible light photoinitiating systems for different types paper the use of novel 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives with an electron-donating of photopolymerization processes. We proposed in this potentials were examined as components of visible light photoinitiating systems for different types paper the use of novel 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives with an electron-donating of photopolymerization processes These 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives group incorporated into this structure moiety that will further increase the efficiency of sensitization. The new compounds with better spectroscopic properties and lower oxidation potentials were examined (radicals or cations) in order to initiate both the free radical polymerization of (meth)acrylates and as components of visible light photoinitiating systems for different types of photopolymerization processes. Light Absorption and Fluorescence Properties of the 2-Amino-4,6-Diphenyl-Pyridine-3-Carbonitrile

Results and Discussion
13 C NMR and LC–MS
Cationic
Conversion of double bonds of trimethylolpropane triacrylate
Thiol-Ene
10. Conversion double bonds recorded of TMPTA during free-radical
12. Profiles
13. Polymerization
14. Profiles of CADEofepoxy group conversion
17. Polymerization rate profiles for photopolymerization of TMPTA
Materials
Experimental Section
Molecular Absorption Spectra Measurements
Fluorescence Spectra Measurements
Structures
Steady-State Photolysis Measurements
Fluorescence Quenching Measurements
Electrochemical Determination of Oxidation Potentials
Molecular Orbital Calculations
Preparation of Photocurable Compositions
Monitoring the Photopolymerization Processes by Real-Time FTIR
Source of Light for Real-Time FTIR Measurements
The Laser Engraver Printer Machine
SLA Home-Made 3D Printer
Microscope Images
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call