Oxygen Inhibition of Radical Polymerizations Investigated with the Rheometric Quartz Crystal Microbalance
Oxygen Inhibition of Radical Polymerizations Investigated with the Rheometric Quartz Crystal Microbalance
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DOI：
10.1021/acs.macromol.8b00720
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发表时间：
2018-07
期刊：
影响因子：
5.5
通讯作者：
C. Yeh;Michael Hu;K. Shull
中科院分区：
文献类型：
--
作者：
C. Yeh;Michael Hu;K. Shull
用流变石英晶体微天平（QCM）作为光固化体系的定量固化监测。该技术需要使用厚度在微米范围内的薄膜，并且基于在15 MHz频率下对薄膜流变特性的直接测量。为了获得比QCM测量的~ 1 s分辨率快得多的固化过程，设计了一个旋转快门系统，以~ 1 ms的时间分辨率捕获过程。在空气和氮气环境下研究了光固化工艺，并将其应用于传统的激进聚合丙烯酸体系和硫醇基体系。在氧气中固化的硫醇体系与在氮气中固化的体系具有相当的刚度，但固化时间更长，并且最终材料中含有1-2.5 wt %的氧气。这些结果表明，QCM可以作为一种有效的光流变学技术，能够为光反应过程提供有用的机理见解。
The use of the rheometric quartz crystal microbalance (QCM) as a quantitative cure monitor for photocuring systems was demonstrated. The technique requires the use of films with thicknesses in the micrometer range and is based on the direct measurement of the rheological properties of the film at a frequency of 15 MHz. To access curing processes much faster than the ∼1 s resolution of the QCM measurement, a rotating shutter system was designed to capture processes with a temporal resolution of ∼1 ms. The photocuring process was studied in both air and nitrogen environments and was applied to a traditional, radically polymerized acrylic system and a thiol–ene based system. Thiol–ene systems cured in oxygen reach comparable stiffnesses to those cured in nitrogen but take longer to cure and contain 1–2.5 wt % oxygen in the final materials. These results indicate that the QCM can be utilized as an effective photorheometric technique able to provide useful mechanistic insight into photoreactive processes.