ISSN 1008-5548

CN 37-1316/TU

最新出版

可聚合型吩噻嗪硫鎓盐光引发剂的合成及性能

Synthesis and performance of multiband responsive phenothiazinium salt-based polymerizable photoinitiators


刘鹏程,李 伦,刘 仁,朱 乙

江南大学 化学与材料工程学院,光响应功能分子材料国际联合研究中心,江苏 无锡214122


引用格式:

刘鹏程,李伦,刘仁,等. 可聚合型吩噻嗪硫鎓盐光引发剂的合成及性能[J]. 中国粉体技术,2025,31(4):1-12.

LIU Pengcheng, LI Lun, LIU Ren, et al. Synthesis and performance of multiband responsive phenothiazinium salt-based polymerizable photoinitiators[J]. China Powder Science and Technology,2025,31(4):1−12.

DOI:10.13732/j.issn.1008-5548.2025.04.008

收稿日期:2025-01-06,修回日期:2025-04-06,上线日期:2025-05-30。

基金项目:国家自然科学基金项目,编号:22301107、52373057;江苏省自然科学基金项目,编号: BK20242080;江南大学合成与生物胶体教育部重点实验室项目,编号:10420502055243170/008。

第一作者简介:刘鹏程(2000—),男,硕士生,研究方向为新型光引发剂体系的设计合成。E-mail:15895323212@163. com。

通信作者简介:朱乙(1989—),男,副教授,博士,硕士生导师,研究方向为新型光引发剂体系的设计合成等。E-mail:zhuyi@jiangnan.edu. cn。


摘要:【目的】 开发低迁移性的长波长可聚合光引发剂,实现自由基和阳离子聚合,从而扩展光引发剂及光聚合的应用范围。【方法】 利用吩噻嗪苯甲酰硫鎓盐在紫外、可见及近红外区域的吸收特性,在该引发剂结构中引入丙烯酸酯基团,设计并合成了一种多波段响应可聚合型的吩噻嗪硫鎓盐长波长光引发剂;采用紫外-可见吸收光谱、实时红外、差示扫描量热法等方法对光引发剂的结构、光物理、光化学、迁移性和热稳定性能进行研究。【结果】 紫外-可见吸收谱图表明该引发剂能够响应紫外、可见及近红外光;光聚合动力学研究表明,该引发剂在紫外、可见及近红外光的辐照下表现出优异的引发性能,能够有效诱导自由基及阳离子聚合反应;迁移性和热稳定性研究表明,该引发剂具有低迁移性和较高的热聚合温度。【结论】 合成的可聚合型的低迁移吩噻嗪硫鎓盐光引发剂,具有多波段响应的特性,在光源的辐照下能够同时引发自由基和阳离子聚合,具有良好的热稳定性和低迁移性,可以应用于食品包装、生物医药等领域。

关键词:光固化;吩噻嗪;可聚合光引发剂;低迁移性;近红外光

Abstract

Objective Photopolymerization is a widely utilized technique across various fields due to its environmentally friendly and efficient characteristics. During the process of photopolymerization, photoinitiators (PIs) are essential in determining the excitation wavelength, polymerization type, polymerization rate, and the final material properties. However, conventional PIs are hindered by two photophysical phenomena, the inner filter effect, where PIs and their photodegradation byproducts concentrated at the material’s surface absorb most of the incident light, and Rayleigh scattering, where a significant portion of incident light is scattered on the surface of a photopolymerization system. These effects prevent subsurface PIs from receiving sufficient activation energy for photolysis, leading to reduced polymerization efficiency, shallow cure depths, and impaired material performance. Additionally, the small molecules generated from conventional PIs may migrate within the cured material, potentially leading to toxicity. To address this issue, low-migration, multiband responsive polymerizable PIs have been developed.

Methods A photopolymerizable methacrylate phenacyl phenothiazinium salt (Acry-P-PTh) was synthesized by incorporating acrylic ester groups. Its structure, photophysical properties, photochemical behavior, migration ratio, and thermal stability were investigated using ultraviolet-visible absorption (UV-Vis) spectroscopy, real-time infrared (RT-IR) spectroscopy, and differential scanning calorimetry (DSC).

Results and Discussion UV-Vis analysis revealed that Acry-P-PTh was responsive to ultraviolet(UV), visible, and near-infrared (NIR) light, with the peak absorption wavelength shifting to 520 nm, a 5 nm redshift compared to phenacyl phenothiazinium salt (P-PTh). Photopolymerization kinetics demonstrated that Acry-P-PTh effectively initiated both free radical and cationic polymerization. Under 365 nm, 405 nm, and 850 nm irradiation, Acry-P-PTh generated benzoyl radicals and Brønsted superacids through C-S bond homolysis. This dual initiation mechanism enabled the polymerization of both acrylate monomers, trimethylolpropane triacrylate (TMPTA), and cationic monomers, EPOX, achieving excellent initiation performance in hybrid systems compared to single-monomer resin systems. Specifically, under 365 nm light irradiation, the final free radical conversion rate exceeded 50%, and the final cationic conversion rate exceeded 40%; under 405 nm light irradiation, the final free radical conversion rate exceeded 45%, and the final cationic conversion rate exceeded 45%. Notably, under 850 nm light, EPOX cationic polymerization achieved a 40% conversion rate within 30 min. Migration studies confirmed that Acry-P-PTh exhibited low migration, with post-curing migration ratios lower than those of P-PTh, measuring 4. 9% for the free radical system and 3. 5% for the cationic system. Thermal stability analysis further revealed high thermal resistance, with polymerization temperatures for free radical and cationic polymerization being 233 ℃ and 78 ℃, respectively. These properties make Acry-P-PTh a promising material for various applications, such as food packaging and biomedicine manufacturing.

Conclusion The synthesized Acry-P-PTh demonstrates broadband absorption across the ultraviolet-visible-near-infrared (UV-Vis-NIR) spectrum. Compared to P-PTh, Acry-P-PTh shows reduced low migration ratio. When mixed with Acry-P-PTh with TMPTA and EPOX monomers, the photocurable system is able to resist higher thermal polymerization temperatures, demonstrating excellent thermal stability. In conclusion, Acry-P-PTh, as an advanced photoinitiator, holds significant potential for practical applications.

Keywords:photocuring; phenothiazine; polymerizable photoinitiator; low migration; near-infrared


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