Leveraging flame retardant efficacy of pomegranate rind extract, a novel biomolecule, on ligno-cellulosic materials

For the first time, pomegranate rind extract (PRE), a wastage agricultural product, has been explored as novel fire retardant (FR) material. The fire retardancy of PRE has been successfully demonstrated on ligno-cellulosic jute material where it was incorporated at different application pH. PRE contains nitrogenous compounds, polyphenolic components and other metallic elements in the form of salts or oxides. Metallic salts and other polar groups present in PRE help to improve moisture uptake (observed from DSC analysis), phenolic compounds present in PRE have improved the smoldering and char promoting behavior. Combinedly all these components present in PRE assisted to exhibit intumescent condensed phase mechanism of fire retardancy when it was applied on the ligno-cellulosic material. PRE incorporation to the jute sample in alkaline pH showed limiting oxygen index (LOI) of 38% whereas in case of control jute sample LOI value was recorded as 22%. Besides, the treated jute material bestowed self-extinguishment with a char length of 60 mm. The rate of weight loss of the treated material is far behind as compared to the control sample and more than 40% char mass was remained at 500 °C compared to the 5% char mass in case of control jute as analyzed by thermo-gravimetry.