Combustion properties of paper treated with chicken egg shell: A potential solid waste

A sustainable flame-resistant paper was prepared by using chicken egg shell, a solid waste material. Chicken Egg shell powder was dissolved in water (pH 4.5) and the mixture (ESS) has been applied on the paper by padding technique at different concentrations (200 and 300 g/L), followed by drying. Treated papers have shown LOI of 23%-27% and the applied organic coating also assisted to arrest flame spread time, smoke density and afterglow time in flammability test. Char morphology of the treated paper revealed that bio calcium carbonate present in the ESS act as an volume expansion agent, reduced the heat flow rate through-out the paper. Thermo-oxidative decomposition of the dried ESS has shown 100% mass retention up to 500 degrees C and the treated paper shows earlier decomposition (catalytic pyrolysis) and 25% more char mass retention at higher temperature as compared to the control paper material. Forced combustion results at 35kw/m2 revealed that ESS treated paper has shown almost 50% less heat release as compared to the control paper. Besides, mechanism lies behind the flame retardancy has been established. Tensile strength properties of the control and the treated paper also has been examined and registered in the context. Finally, dye ability of the ESS treated paper also has been examined with both anionic and cationic dyes.