Synthesis of carboxymethyl starch grafted poly (methacrylic acids) (CMS-g-PMAAs) and their application as an adsorbent for the removal of ammonia and phenol

In this study carboxymethyl starch grafted poly(methacrylic acids) (CMS-g-PMAAs) were synthesized by treating carboxymethyl starch with methacrylic acid in the presence of initiator potassium persulfate (KPS). The modified starches were characterized by proton nuclear magnetic resonance (1H NMR) and fourier-transform infrared (FT-IR) spectroscopy. The crystallinity of the modified starches was analyzed by x-ray diffraction (XRD) while thermal properties of the modified starches were found out by thermogravimetric analysis (TGA) and differential thermal analysis (DTG). These modified starches were then tested as an adsorbent for the removal of ammonia and phenol from the gaseous mixture. The maximum adsorption efficiencies of CMS, CMS-g-PMAA1, CMS-g-PMAA2, and CMS-g-PMAA3 for ammonia were 0.005, 0.020, 0.023 and 0.031 g/g respectively. Similarly, for phenol, the maximum adsorption efficiencies of CMS, CMS-g-PMAA1, CMS-g-PMAA2 and CMS-g-PMAA3 were shown to be 0.2085, 0.2445, 0.2473 and 0.2501 g/g respectively. It was shown that CMS-g-PMAAs could be used as an additive in cigarette filters to remove the toxicant ammonia and phenol from cigarette smoke.