Preparation of Starch‐Based Bionanocomposite Hydrogel with Mica for Fire Retardancy

ABSTRACT We know that starch is formed from granules separated from each other. When grafted with butyl acrylate (BA), those granules became more in contact and coherent to formed a merged network‐like spongy structure, which upholds a large amount of water to show improved water absorbency. BA was grafted onto starch to obtain a novel starch‐ g ‐poly(butyl acrylate) (PBA) biocopolymer hydrogel and formed a bionanocomposite hydrogel with mica as the additive for fire retardancy and was characterized by FTIR, SEM, and TGA. The insertion of mica into the starch‐ g ‐PBA exhibited an intercalated structure as confirmed by XRD and TEM analyses and also supported the hydrogel as a bionanocomposite, which showed an improved water absorbency and biodegradability with a better thermal stability. Cone calorimetric analysis evaluated the pronounced fire retardancy of the novel starch‐ g ‐PBA/mica bionanocomposite, providing an excellent protection in delaying the ignition time with greatest extension of time at a peak heat release rate on exposure to fire.