Objective

To synthesize an amine-modified polyhedral oligomeric silsesquioxane (POSS) nano-structure as a novel co-initiator-crosslinker (co-Ini-Linker) and to determine the effect of the co-Ini-linker on the physical and mechanical behavior of an experimental dental composite.

Methods

The amine-methacrylate POSS nano-structures (AMA-POSS) were chemically synthesized by anchoring a tertiary amine functionality on the methacrylate POSS (MA-POSS) branches. Three types of AMA-POSS, having different amine branches in their structures, were synthesized through the Aza Michael reaction. The chemical structure of AMA-POSSs were evaluated by¹H-NMR spectroscopy. Afterward, the AMA-POSS was incorporated into a dental resin system composed of Bis-GMA, TEGDMA, and photo-initiator. Three resin systems with different AMA-POSS types were then prepared, and their properties were compared with a resin containing DMAEMA as a conventional co-initiator. The degree of conversion evaluated by FTIR spectroscopy and the shrinkage kinetics of the resins were determined through the bonded-disk technique. The flexural properties of the photopolymerized resins were also investigated. The distribution of nano-structures in the matrix resin was analyzed using EDX analysis.

Results

The modified POSS structure and the number of amine branches were confirmed with¹H-NMR spectroscopy. The resin containing 8 amine branches (P8) showed the same degree of conversion (DC%) as the resin containing DMAEMA (P > 0.05). Decreasing the amine branches in the POSS structure, however, revealed an increasing trend in DC%. The resin containing P8 showed the lowest shrinkage strain. By incorporating AMA-POSS into the resin system, the water sorption significantly decreased (P < 0.05). The flexural strength and modulus increased by adding P3 into the resin system (P < 0.05). EDX Si-map revealed that the co-Ini-linker was well dispersed in the resin matrix.

Significance

The synthesized novel amine-methacrylate POSS nanostructures not only act as an amine co-initiator but also work as a reinforcing filler and a cross-linking agent.

中文翻译：

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作为新型共引发剂-交联剂的改性 POSS 纳米结构：合成和表征

客观的

合成胺改性的多面体低聚倍半硅氧烷 (POSS) 纳米结构作为新型共引发剂-交联剂 ( co -Ini-Linker) 并确定共Ini-linker 对树脂物理和机械行为的影响实验性牙科复合材料。

方法

胺-甲基丙烯酸酯 POSS 纳米结构 (AMA-POSS) 是通过将叔胺官能团锚定在甲基丙烯酸酯 POSS (MA-POSS) 分支上而化学合成的。通过 Aza Michael 反应合成了三种结构中具有不同胺支链的 AMA-POSS。AMA-POSSs 的化学结构通过¹H-核磁共振光谱。之后，AMA-POSS 被纳入由 Bis-GMA、TEGDMA 和光引发剂组成的牙科树脂系统中。然后制备了具有不同 AMA-POSS 类型的三种树脂体系，并将它们的性能与含有 DMAEMA 作为常规共引发剂的树脂进行了比较。由 FTIR 光谱评估的转化程度和树脂的收缩动力学通过粘合盘技术确定。还研究了光聚合树脂的弯曲性能。使用EDX分析来分析基质树脂中纳米结构的分布。

结果

经¹ H-NMR 光谱证实了修饰的 POSS 结构和胺支链的数量。含有 8 个胺支链的树脂 (P8) 显示出与含有 DMAEMA 的树脂相同的转化率 (DC%) ( P > 0.05)。然而，减少 POSS 结构中的胺支链表明 DC% 呈增加趋势。含有 P8 的树脂显示出最低的收缩应变。通过将 AMA-POSS 加入树脂体系，吸水率显着降低（P < 0.05）。通过在树脂体系中加入 P3，弯曲强度和模量增加（P < 0.05）。EDX Si-map 显示共Ini-linker 很好地分散在树脂基质中。

意义

合成的新型胺-甲基丙烯酸酯 POSS 纳米结构不仅可以作为胺共引发剂，还可以作为增强填料和交联剂。