Cross-linking reaction of polymer by atmospheric pressure plasma jet

Abstract

Utilization of atmospheric pressure plasma jet (AP plasma jet) as the energy source was investigated for a cross-linking reaction of PVA resist films containing diphenyl-4-diazonium sulfate/formaldehyde condensate (DSR). The AP plasma jet has a character of high-energy field at a low temperature. Furthermore it can supply various type of energy to extremely re-stricted region of target materials regardless of the shape and/or surface condition. The DSR/PVA-coated film cured in dot by AP plasma jet irradiation, and the diameter of the cured area increased with irradiation time. Therefore some experiments were progressed to study the major factor contributing to the cross-linking reaction. At first the role of diazo compound was estimated. The PVA-coated film did not cure with plasma irradiation under a condition of DSR absence. Secondly an effect of emitted UV light on the cross-linking reaction was investigated. No cured film was obtained, when a coated film was placed in parallel to AP plasma jet in order to avoid plasma bombardment on the film. This series of experimentations suggested that a diazo compound played a pivotal role in propagation of cross-linking reaction, and that its photodecomposition it did not significantly take place in our AP plasma jet system. Furthermore an effect of heat could be neglected inasmuch as the AP plasma jet is categorized in thermal nonequilibrium plasma. As the conclusion, it was suggested an energy transfer from active species in plasma to diazo compound to be the key reaction of our system. © 2012CPST.