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Publikace detail

The study of systems cured by free radical and cationic mechanism simultaneously
Autoři: Škola Ondřej | Jašúrek Bohumil | Vališ Jan | Němec Petr
Rok: 2014
Druh publikace: ostatní - článek ve sborníku
Název zdroje: Book of Abstracts IDMS 2014 ReAdMat
Název nakladatele: Univerzita Pardubice
Místo vydání: Pardubice
Strana od-do: 60
Tituly:
Jazyk Název Abstrakt Klíčová slova
eng The study of systems cured by free radical and cationic mechanism simultaneously UV printing inks and varnishes are cured by free radical or cationic polymerization. Systems polymerizing by free radical polymerization are cured very fast (fraction of seconds), but their disadvantage is inhibition by atmospheric oxygen. Systems polymerizing by cationic polymerization aren’t inhibited by atmospheric oxygen and have excellent adhesion to various substrates, but these systems are inhibited by air humidity. Hybrid UV systems that are cured simultaneously by free radical and cationic polymerization, have some properties better than systems polymerizing by only free radical or cationic polymerization. For example, hybrid systems have lower sensitivity to inhibition by atmospheric oxygen and air humidity, thus the final film properties could be better than those of systems cured by only free radical or cationic polymerization. The aim of this work was to study the polymerization reaction of hybrid systems and to compare them with systems polymerizing by only free radical or cationic polymerization. Hybrid systems were prepared from photoinitiators Darocure 1173 (free radical photoinitiator) and Irgacure 250 (cationic photoinitiator), and monomers pentaerythritol triacrylate (free radical polymerization) and Uvacure 1500 (epoxyde monomer, cationic polymerization). The molar ratio of monomers in hybrid systems was 1:1, 1:3 and 3:1. Concentration of photoinitiator was 3 mol% in all cases. The degree of conversion was evaluated based on results obtained from FTIR spectroscopy. The polymerization reaction of samples was observed for various UV doses (medium pressure mercury lamp as UV source) and the optimal UV dose was estimated from FTIR spectra. The results show that hybrid polymerization systems reached higher overall degree of conversion. UV curing; free radical polymerization; cationic polymerization; hybrid polymerization