Effects of allyloxy substitution on photochemical properties of thioxanthones and their application in Visible-LED photopolymerization

IF 5.8 2区化学 Q1 POLYMER SCIENCE

European Polymer Journal Pub Date : 2025-05-03 DOI:10.1016/j.eurpolymj.2025.114005

Guanyu Sheng , Yonghui Wang , Xiaoqiang Dai , Qinyan Zhu , Ming Jin

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Abstract

Photoinitiators are essential for advanced photopolymerization technologies. Thioxanthones, particularly ITX, serve as important Type II photoinitiators due to their efficient radical generation via hydrogen abstraction. However, ITX faces critical limitations: mutagenicity, short absorption wavelength (<400 nm), and high migration. Although 1,4-dimethoxy substitution red-shifts absorption to 425 nm, it reduces photolytic efficiency. To overcome these issues, here we designed and synthesized thioxanthone derivatives featuring strategically substituted allyl and propyl groups at the 1,4-positions of the thioxanthone core. Our results reveal that the 1-position allyloxy group enhances electron delocalization, modifying excited-state dynamics to boost photolysis rates and polymerization efficiency. This design simultaneously achieves strong visible-light absorption (ε_425nm > 800 M⁻¹cm⁻¹) and a 90 % reduction in migration compared to ITX. The work demonstrates a rational strategy to develop high-performance, low-migration photoinitiators for visible LEDs curing systems.

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烯丙氧基取代对硫代蒽酮光化学性质的影响及其在可见光led光聚合中的应用

光引发剂对于先进的光聚合技术是必不可少的。硫代蒽酮，特别是ITX，是重要的II型光引发剂，因为它们通过抽氢产生自由基的效率很高。然而，ITX面临着关键的局限性：诱变性、短吸收波长（<400 nm）和高迁移性。虽然1,4-二甲氧基取代使吸收红移至425 nm，但降低了光解效率。为了克服这些问题，我们设计并合成了硫氧杂蒽酮衍生物，在硫氧杂蒽酮核心的1,4位上战略性地取代了烯丙基和丙基。我们的研究结果表明，1位烯丙氧基可以增强电子离域，改变激发态动力学，从而提高光解速率和聚合效率。本设计同时实现了强可见光吸收(ε425nm >；800 M−1cm−1)，与ITX相比迁移减少了90%。这项工作展示了一种合理的策略来开发高性能、低迁移的光引发剂，用于可见光led固化系统。

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来源期刊

European Polymer Journal 化学-高分子科学

CiteScore

9.90

自引率

10.00%

发文量

691

审稿时长

23 days

期刊介绍： European Polymer Journal is dedicated to publishing work on fundamental and applied polymer chemistry and macromolecular materials. The journal covers all aspects of polymer synthesis, including polymerization mechanisms and chemical functional transformations, with a focus on novel polymers and the relationships between molecular structure and polymer properties. In addition, we welcome submissions on bio-based or renewable polymers, stimuli-responsive systems and polymer bio-hybrids. European Polymer Journal also publishes research on the biomedical application of polymers, including drug delivery and regenerative medicine. The main scope is covered but not limited to the following core research areas: Polymer synthesis and functionalization • Novel synthetic routes for polymerization, functional modification, controlled/living polymerization and precision polymers. Stimuli-responsive polymers • Including shape memory and self-healing polymers. Supramolecular polymers and self-assembly • Molecular recognition and higher order polymer structures. Renewable and sustainable polymers • Bio-based, biodegradable and anti-microbial polymers and polymeric bio-nanocomposites. Polymers at interfaces and surfaces • Chemistry and engineering of surfaces with biological relevance, including patterning, antifouling polymers and polymers for membrane applications. Biomedical applications and nanomedicine • Polymers for regenerative medicine, drug delivery molecular release and gene therapy The scope of European Polymer Journal no longer includes Polymer Physics.