Synthesis of sodium alginate grafted methyl methacrylate and its mechanism of coal-dust inhibition

To control coal dust, a novel composite dust suppressant named SA-g-PMMA/APG1214 was created by mixing SA-g-PMMA (sodium alginate grafted methyl methacrylate) with the surfactant APG1214. SA-g-PMMA was synthesized by using 2 g sodium alginate (SA) and 4 g methyl methacrylate (MMA) and 0.12 g ammonium persulfate (APS) as initiator in a water bath at 70 °C for 2 h. Quantum chemistry calculations, experiments, and molecular dynamics simulations were used to investigate the synthesis mechanism and dust-suppression properties. Results indicated that the reactive sites of SA and MMA were located at the O14-H19 and C1 =C2 bonds, respectively. H19 on the hydroxyl group of the SA molecular structure was seized by SO 4 –. produced by the decomposition of ammonium persulfate to generate SA-O . reactive radicals. SA-O . reacted with the C1 =C2 bond in MMA to form the product SA-g-PMMA. A composite dust suppressant with excellent flowability and wettability was obtained by adding 1.3 g/L of APG1214 to SA-g-PMMA. Compared with the water–lignite system, the thickness of the absorbing layer at the lignite /water interface of the dust suppressant–lignite system increased from 14.60 Å to 16.68 Å, and the number of hydrogen bonds rose from 3178 to 3194.