Center of Stomatology, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, Zhejiang, China.
The 3rd People's Hospital of Deqing, Huzhou, Zhejiang, China.
Sci Rep. 2024 Jul 19;14(1):16719. doi: 10.1038/s41598-024-67377-z.
The purpose of this work is to explore the properties of the lignin-derived amine-free photoinitiating systems (PISs) during the curing process. Four novel hydrogen donors (HD1, HD2, HD3, and HD4) derived from lignin α-O-4 structural were designed and synthesized by simple methods, and their low C-H bond dissociation energies on methylene were determined by molecular orbitals theory. Four experimental groups using CQ (camphorquinone)/HD PIs formulated with Bis-GMA/TEGDMA (70 w%/30 w%) were compared to CQ/EDB (ethyl 4-dimethylamino benzoate) system. The photopolymerization profiles and double bond conversion rate was tracked by FTIR experiments; the color bleaching ability of the samples and color aging test assay were performed using color indexes measurements; The cytotoxicity of the samples was also compared to EDB related systems. All of the experimental groups with new HDs were compared to the control group with EDB by statistical analysis. Compared to CQ/EDB system, new lignin-derived hydrogen donors combined with CQ showed comparable or even better performances in polymerization initiation to form resin samples, under a blue dental LED in air. Excellent color bleaching property was observed with the new HDs. Aging tests and cytotoxicity examination of the resin were performed, indicating the new lignin compounds to be efficient hydrogen donors for amine-free CQ-based photo-initiating system. Novel lignin α-O-4 derived hydrogen donors are promising for further usage in light-curing materials.
本工作旨在探索木质素衍生的无胺光引发体系（PIS）在固化过程中的性质。通过简单的方法设计并合成了四个新型木质素α-O-4 结构衍生的供氢体（HD1、HD2、HD3 和 HD4），并通过分子轨道理论确定了其亚甲基上低 C-H 键离解能。将四个实验组（以 CQ（樟脑醌）/HD 为 PIS，以 Bis-GMA/TEGDMA（70 w%/30 w%）为配方）与 CQ/EDB（乙基 4-二甲氨基苯甲酸酯）体系进行了比较。通过 FTIR 实验跟踪光聚合曲线和双键转化率；通过颜色指数测量进行样品的颜色漂白能力和颜色老化测试；还比较了样品的细胞毒性与 EDB 相关体系。通过统计分析，将所有含有新 HD 的实验组与含有 EDB 的对照组进行了比较。与 CQ/EDB 体系相比，在空气中使用蓝色牙科 LED 时，新型木质素供氢体与 CQ 结合表现出相当或更好的聚合引发性能，可形成树脂样品。新型 HD 表现出优异的颜色漂白性能。对树脂进行老化测试和细胞毒性检测，表明新型木质素化合物是有效的无胺 CQ 基光引发体系的供氢体。新型木质素 α-O-4 衍生供氢体有望进一步用于光固化材料。
