Microwave dielectric heating affects the in-situ polymerization process of Nylon-6/Ag-NPs hybrid polymer nanocomposite

In this work, the microwave synthesis of Nylon-6 hybrid polymeric nanocomposite (HPNC) was studied by the polymerization of epsilon-caprolactam, 6-aminocaproic acid, and 2% wt of silver nanoparticles (Ag-NPs). It was determined that the dielectric heating (DH) of the Ag-NPs controls the thermal behavior of the HPNCs synthesis and triggers the chemical reaction between Ag-NPs and the Nylon-6 molecules. Such reaction promotes their coating with the polymer and their precipitation, which affects the agitation of the reaction mixture, and results in broader molecular weight distribution and three HPNC populations. Usually, the power output effect in these processes is thermal as it accelerates their heating rate. Still, for HPNCs, higher output reduces the agglomerate size of the Ag-NPs and accelerates their precipitation. At power up to 600 W, the DH of the Ag-NPs causes the explosion of the reaction vials. The antimicrobial activity of the HPNCs against P. aeruginosa is almost 100% effective at 180 min of exposure; therefore, this microwave synthesis process is suitable for producing antimicrobial HPNCs.