| Autor: |
Treushnikov, V. M., Treushnikov, V. V., Semenov, V. V. |
| Předmět: |
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| Zdroj: |
Russian Microelectronics; Jul2021, Vol. 50 Issue 4, p211-229, 19p |
| Abstrakt: |
The theoretical foundations of frontal photopolymerization (FPP) with an extremely small width of the reaction front in systems in which the front moves not along the direction of propagation of light but perpendicular to it. The influence of the cellular effect on the kinetics of photopolymerization in high-viscosity media is considered. FPP leads to the formation of a defect-free transparent product, when the exit of quasi-particles of free volume from a thin layer of the polymerizing composition with a thickness of Δh subject to Δh → 0 is provided. The fulfillment of this condition is excluded when the conversion front moves along the passage of light beams. It is shown that the required conditions are satisfied by photoinitiators generating free radicals according to the Norrish type 1 reaction. The apparatus, composition, and properties of the compositions implemented in the production of polymer products are described in two ways: (1) expanding the field of irradiation of the composition and (2) moving the composition itself into the irradiation zone. The use of inhibitors in FPP processes, leading to the elimination of parasitic illumination and to a decrease in the front width of the polymerization reaction (chemical focusing), is substantiated. The main instrumental methods of testing photopolymerizable compositions (PPCs) are outlined: methods of a paramagnetic probe (PP), refractometry, IR spectroscopy, and laser interferometry. The basic requirements for the initial connections and equipment, which made it possible to implement FPP on an industrial scale, are presented. Samples of products obtained by this method are presented. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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