New Route for the Production of Thermosensitive Polymer With Pulsed Arc Discharge at the Argon–Water Interface

Poly-N-isopropylacrylamide (PNIPAM) is well known about an exhibition of coil-to-globule transition below the lower critical solution temperature (32 °C) in aqueous media. Because of this temperature near the human body, it has focused on as one of the functional polymers available to industries. However, the synthesis of PNIPAM has been conventionally conducted in combined harmful solvents for considerable long operating times. In this paper, we aimed to develop a novel technique that PNIPAM can be produced in a rapid and selective manner with pulsed discharges at ambient temperature and pressure. Reactions were carried out using a stainless steel batch-type reactor (inner volume: 15 mL) in the presence of 2,
$2^{\prime }$
-Azobis (2-methylpropionamidine) dihydrochloride as an initiator at 25 °C–30 °C, 0.89 M NIPAM aqueous solution, and pulse repetition rates 1–50 pps for 1–15-min treatment times. As the results, in most cases, PNIPAMs were able to be produced within a couple of minutes in relative high production yield and selectivity.