A dual-cure process consisting of two subsequent ultraviolet-initiated radical and cationic polymerizations was investigated. The process was studied with two acrylate oxetane monomers, one of them having a spacer between the two polymerizable moieties. It was shown by Fourier transform infrared (FTIR) that the first (radical) step was performed successfully for both systems. As for the second (cationic) step, only the monomer with the spacer was able to polymerize, allowing the crosslinking of the polyacrylic chains generated by the first step. The efficiency of the process was confirmed by differential scanning calorimetry because the glass-transition temperatures of the cured films were _16 and _ 34 °C after the first and second steps, respectively. The dual cure of this system was further analyzed by real-time FTIR, which showed that 86% of the acrylate and 80% of the oxetane moieties were converted after 20 and 50 s of light exposure, respectively.
|Tijdschrift||Journal of Polymer Science, Part A: Polymer Chemistry|
|Nummer van het tijdschrift||4|
|Status||Gepubliceerd - 2003|