Optimization of preparing poly(AM-DMDAAC)/MMT superabsorbent nanocomposite by orthogonal experiment

Abstract

A novel poly(AM-DMDAAC)/MMT superabsorbent nanocomposites are prepared by radical polymerization using ammonium persulfate APS and anhydrous sodium sulfite as a free radical initiator and ¿VA-methylene bisacry-lamide (MBA) as a crosslinker. In this paper, an optimization study on the synthesis of superabsorbent nanocomposites is carried out. Orthogonal array experiment indicates that the optimized conditions is acrylamide (AM) content 23 wt%, diallyl dimethyl ammonium chloride (DMDAAAC) content 6 wt%, montmorillonite (MMT) content 4 wt%, initiator content 0.2 wt% and crosslinker content 0.02 wt%. Under the optimization syntheses conditions concluded, the maximum water absorbency in distilled water is 659.53 g-g-1 and in 2 wt% sodium chloride solution is 116.25 g-g-1. Compared with the range values of different factors (R), the order of significance factors in distilled water is C MMT > B (DMDAAC) > A (AM) > D (crosslinker) > E (initiator). MMT is intercalated during polymerization reaction and a nanocomposite structure is formed as shown by TEM analysis and XRD analysis.