Palladium particle recovery from nitrile butadiene rubber dissolved in acetone through precipitation of poly(2-(dimethylamino)ethyl methacrylate)

Acrylonitrile butadiene rubber (NBR) has been used in the automotive industry. To change the strength of NBR, the double bond in NBR can be converted to a single bond using palladium particles immobilized on a support as a catalyst. During this catalytic reaction, palladium particles might leak into the solution. In this study, to recover palladium particles from highly concentrated NBR acetone solution, poly(2-(dimethylamino)ethyl methacrylate) (poly(DMAEMA)) solution was added to the palladium-containing solution. The amino group of poly(DMAEMA) captured palladium particles and poly(DMAEMA) shrunk by dehydration in acetone, resulting in rapid precipitation of poly(DMAEMA) complexed with palladium particles. The percentage of recovered palladium particles after 1 h was 60%. By immersing the complex in HNO3 solution including thiourea, 90% of the recovered palladium was eluted from the precipitated poly(DMAEMA).