Studies of new high-performance co-initiators applied to photopolymerization processes in the visible light range for medical application
Authors:
- Paweł Stalmach,
- Wiktoria Tomal,
- Patryk Szymaszek,
- Joanna Ortyl
Abstract
Photopolymerization is a well known method for the production of polymeric materials. Numerous advantages of this process such as: lack of need for solvents, carrying out the reaction at room temperature or low energy consumption make the light-initiated polymerization applied both in chemical industry, optoelectronics, 3D printing and biomedicine. Photoinitiating systems play a key role in photopolymerization processes. It is essential that the initiators used have absorption characteristics compatible with the emission characteristics of the light sources used, preferably from the safe visible range. Unfortunately, the initiators used on the market usually have a relatively short absorption range, while this problem can be solved by using an additional component, the so-called photosensitizer. Therefore, due to the continuous search for efficient initiator systems, this work proposes the use of iridium(III) complexes as highly efficient sensitizers of commercially used initiator in the form of iodonium salt in cationic and radical photopolymerization processes. The first stage of work was to study the absorption characteristics of iridium complexes in acetonitrile. The investigated compounds absorb in the range of 200 nm - 510 nm, which enables the use of light sources emitting radiation in the safe range, such as Vis-LED in the range of 365 nm to 470 nm. High values of molar extinction coefficients at the mentioned wavelengths ensure that these iridium complexes can successfully act as photosensitizers of iodonium salts in the analyzed range. In the next part of the work the effectiveness of the studied complexes as a photosensitizer of iodonium salt in cationic and radical photopolymerization processes was verified. Polymerization of TEGDVE vinyl monomer and TMPTA monomer was carried out using a two-component initiator system: Speedcure® 938 (1.0 % concentration) as initiator and the tested iridium complexes (0.1 % concentration) as co-initiator. Photopolymerization was carried out using different light sources: VisLED @365 nm @405 nm @415 nm, @455 nm and @470 nm. The polymerization process was analyzed using an FT-IR spectrometer with a horizontal attachment. The changes occurring during the photopolymerization process were then monitored using the fluorescence probe technique (FPT), which involves measuring the changes in the fluorescence characteristics of the corresponding fluorescent molecular probes along with the changes occurring in the probe environment. The most commonly used parameter to monitor the progress of polymerization is the ratio of fluorescence intensity measured at two different wavelengths on either side of the spectral maximum, referred to as the R parameter. This parameter increases as polymerization progresses as the spectrum shifts toward shorter wavelengths and becomes a quantitative determinant of the process.
- Record ID
- CUT3bac02af2a184d1184f41fe45300ed50
- Publication categories
- ; ;
- Author
- Pages
- [158]
- Substantive notes
- Sesja: Medicinal Chemistry
- Miejsce wyd. i miejsce konf. wg siedziby org.
- Wydawca wg org. konf.
- Data wyd. wg daty konf.
- Book
- AMYC-BIOMED 2021 : 2nd Autumn Meeting for Young Chemists in Biomedical Sciences, 3-5 November 2021 – virtual conference : e-book of abstracts, 2021, [Naples], University of Naples Federico II, ISBN 978-88-94952-19-3
- Keywords in English
- visible light, photopolymerization, photoinitiating systems
- URL
- https://amyc-biomed-2021.webnode.it/chi-siamo/ Opening in a new tab
- Related project
- Molecular design, synthesis and application of photoinitiator-catalysts (PICs) for photopolymerization reactions. . Project leader at PK: , ,
- Language
- eng (en) English
- License
- Score (nominal)
- 0
- Uniform Resource Identifier
- https://cris.pk.edu.pl/info/article/CUT3bac02af2a184d1184f41fe45300ed50/
- URN
urn:pkr-prod:CUT3bac02af2a184d1184f41fe45300ed50
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