One-Pot Synthesis of Thermoresponsive Poly(N-Isopropylacrylamide) Assisted by Pulsed Arc Discharge in Contact with the Water Interface for Wound Dressing Purposes

Synthesis of thermoresponsive polymers has been developed via several different methods among the years, radical polymerization being the most used. There are many ways to produce the radicals necessary for polymerization, but most recently, plasma-initiated polymerization methods like arc and streamer discharge have been attracting attention. Electric discharges are improved by the utilization of pulsed power science, which counts with the advantage of accumulating energy over a relatively long period of time and realizes it quickly, thus increasing the instantaneous power. In this research, pulsed arc discharge and chemical polymerization methods are compared. The results showed that by changing the discharge conditions, it was possible to obtain polymers with different molecular sizes and weights, viscosities, and crystallinities, while using the azo polymerization method, the decisive factor turns out to be the initiator concentration. This tunable aspect of the pulsed arc discharge method poses a promising alternative to produce a polymer with specific characteristics for specific applications such as in wound dressing. Furthermore, a seldomly used azo initiator 2,2'-azobis(2-methylpropionamidine) dihydrochloride was used for its good solubility in water, and this work aims to give more insight into how the pulsed arc discharge affects the decomposition of this compound.