Production and Characterisation of Activated Carbon from Rubber Wood Waste for Industrial Polymer Purification Applications

Activated carbon is a critical material in polymer purification processes, used to remove colour bodies, catalyst residues, and low-molecular-weight impurities from polymer solutions and melts. This study investigates the production and characterisation of activated carbon from rubber wood waste generated by the rubber plantation industry in Edo State, South South Nigeria. Rubber wood was carbonised at temperatures of 500, 600, and 700 degrees Celsius, followed by chemical activation using zinc chloride and potassium hydroxide at varying impregnation ratios. Activated carbon products were characterised for BET surface area, pore volume, pore size distribution, iodine number, methylene blue adsorption, and proximate analysis. Adsorption capacity for methylene blue dye from aqueous solution was used as a surrogate test for colour body removal relevant to polymer purification. Results indicate that potassium hydroxide activation at an impregnation ratio of 2:1 at 700 degrees Celsius produced the highest BET surface area of 1240 m2/g and iodine number of 950 mg/g. Methylene blue adsorption capacity reached 310 mg/g under optimal activation conditions. Pore size distribution confirmed a predominantly microporous structure with a mean pore diameter of 1.8 nanometres, suitable for adsorbing small molecular weight colour bodies. Zinc chloride activation produced lower surface areas but broader mesopore distribution, potentially advantageous for higher-molecular-weight impurity removal. The study recommends rubber wood-derived activated carbon as a viable domestically produced alternative to imported grades for polymer purification applications in South South Nigeria. Keywords: activated carbon, rubber wood, polymer purification, BET surface area, Edo State