Simultaneous Real-Time Analysis of Bulk and Bottom Cure of Ultraviolet-Curable Inks Using Fourier Transform Infrared Spectroscopy

Abstract

The curing characteristics of an ultraviolet (UV) ink layer are of utmost importance for the development of UV inks. Measuring either bulk or bottom cure in itself is not new and has been the subject of many articles. In this article, two methods are described based on Fourier transform infrared (FT-IR) spectrometry to measure in real time and simultaneously the bulk and bottom cure of a thin UV ink layer. The procedure consists of applying a thin (10-12 µm) layer of UV-curing ink on an attenuated total reflection (ATR) crystal. The bottom cure is measured with ATR. The bulk cure is measured simultaneously with a reflection analysis (method 1) or a transmission analysis (method 2). With both methods, the bulk and bottom cure can be determined. To overcome problems with the interference in the ATR reflection setup, it is recommended to use the ATR transmission setup.

Mathematical modelling for 1,6‐hexanediol diacrylate photopolymerization in presence of oxygen

“…Details about the computation of vinyl-group conversions from the real-time FTIR measurements are provided elsewhere. [23] Eight runs from the described dataset are used for parameter estimation in the current article. The selected runs include three runs with light intensities of 200, 500, and 750 W/m 2 from the first series of experiment, and five runs from the factorial series, whose targeted settings were z f = 8 μm, I l,0 = 1000 W/m 2 , and [BAPO] = 1 or 4 wt.%.…”

“…Details about the computation of vinyl‐group conversions from the real‐time FTIR measurements are provided elsewhere. [ 23 ]…”

“…Experimental details are provided elsewhere. [21,23] Data were collected from two sets of experiments. A series of 12 experimental runs was conducted for the polymerization of HDDA films with a thickness z f of $12 μm and an initiator concentration of [BAPO] = 4 wt.%.…”

“…[20][21][22] An early model developed by Iedema et al was proposed for the photocuring of HDDA in the absence of oxygen. [20] Experimental data obtained using real-time transmission Fourier-transform infrared reflection (trans-FTIR) [23] were used to tune the kinetic parameters used in the model, which predicts the conversion of vinyl groups. A second modelling work focused on the thermomechanical properties and topology of HDDA polymer networks using molecular dynamics and graph theory tools.…”

In situ polymerization monitoring of a diacrylate in an electrically conducting mesoporous nanoparticle scaffold

“…[31] For consistency, the results for the polymerization of the pure phase in a thin film were referenced against other HDDA studies that underwent different photoinitiation treatments but showed the same reaction kinetics, e.g., in dynamic photo-calorimetry scans with other photo-initiators. [32][33][34] Experimental section…”