Institute of Physical Chemistry, Universität Hamburg, Grindelallee 117, 20146, Hamburg, Germany.
Institute of Polymer Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, 21502, Geesthacht, Germany.
Macromol Rapid Commun. 2020 May;41(9):e2000029. doi: 10.1002/marc.202000029. Epub 2020 Feb 26.
Gapless monitoring of polymerization reactions is of paramount interest for academia and the polymer industry, allowing for efficient reaction screening and precise tailoring of the polymeric products. Herein, UV-visible spectroscopy (UV-vis) is employed as an operando measurement technique in continuous flow polymerization with ex situ calibration, to calculate monomer conversions with unprecedented resolution of only 10 s. A mathematical model based on volume contraction is provided for the first time, which yields monomer conversions from the absorption in the visible region for theoretically any homopolymerization. This model is validated for different monomers, solvents, and concentrations in a photoiniferter reversible addition-fragmentation chain transfer polymerization, proving the versatility of the presented setup. Notably, an ultralow measurement volume of merely a few hundred nanoliters is enough to ensure high accuracy.
无间隙监测聚合反应对于学术界和聚合物工业至关重要，可实现高效的反应筛选和对聚合物产品的精确定制。在此，采用紫外-可见光谱（UV-vis）作为连续流聚合中的一种操作测量技术，并结合异位校准，可实现前所未有的仅 10 s 分辨率的单体转化率计算。首次提供了一种基于体积收缩的数学模型，可根据可见区域的吸收计算任何均聚反应的单体转化率。该模型已针对不同单体、溶剂和浓度的光引发剂可逆加成-断裂链转移聚合进行了验证，证明了所提出的设置的多功能性。值得注意的是，仅几百纳升的超低测量体积就足以确保高精度。
