VUV-Induced Photopolymerization of Acrylates

• Published in: Macromolecular chemistry and physics 2012-02, Vol.213 (3), p.324-334
• Main Author: Scherzer, Tom
• Format: Article
• Language: English
• Subjects: acrylates; Applied sciences; Exact sciences and technology; irradiation; kinetics (polym.); photopolymerization; Physicochemistry of polymers; Polymerization; Polymers and radiations; real-time FTIR spectroscopy
• ISSN: 1022-1352; 1521-3935
• DOI: 10.1002/macp.201100485

Acrylates and methacrylates are photopolymerized without photoinitiator by exposure to 172 nm radiation. The kinetics of the polymerization is studied using real‐time Fourier‐transform infrared attenuated total reflectance (FTIR‐ATR) spectroscopy. It is shown that layers with a thickness of ≈500 nm can be polymerized very rapidly. The effect of structure, viscosity, functionality, and absorption of the acrylates as well as the influence of temperature and oxygen concentration on the reactivity are studied. A strong conversion gradient is observed in layers up to ≈2 μm thickness, which reflects the intensity gradient within the layer. However, the penetration of the polymerization into the layer exceeds the initial penetration depth of the VUV radiation, which indicates strong bleaching of the acrylates during irradiation. Acrylates and methacrylates can be photopolymerized without photoinitiator using 172 nm radiation. Real‐time FTIR‐ATR spectra show that layers with ≈500 nm thickness can be polymerized rapidly. The penetration of the polymerization into the layer was found to exceed the initial penetration depth of the VUV radiation, which indicates bleaching of the acrylates during irradiation.