Synthesis and characterization of lignin-poly(acrylamide)-poly(2-methacryloyloxyethyl) trimethyl ammonium chloride copolymer

In this work, two monomers, acrylamide (AM) and [2-(methacryloyloxy)ethyl]trimethylammonium chloride (DMC) were copolymerized from kraft lignin (KL) in an aqueous suspension initiated by free radical copolymerization in the presence of potassium persulfate. The impact of copolymerization conditions on the charge density and molecular weight of the copolymers was investigated. The molecular weight and mass balance analyses confirmed that the homopolymer [polyDMC (PDMC) and polyAM (PAM)] and undesired copolymer (AM-DMC) productions dominated as time, initiator, and DMC dosage increased more than the optimum values. The activation energy of the polymerization of KL and AM (43.02 kJmol(-1)), KL and DMC (21.99 kJmol(-1)), AM (14.54 kJmol(-1)), DMC (10.34 kJmol(-1)), and AM and DMC (18.13 kJmol(-1)) was determined. Proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermogravimetric analysis, and elemental analysis confirmed the production of KL-AM-DMC copolymer. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46338.