Synthesis and characterization of superabsorbent natural polymers from agro-waste fibres

Abstract

This work focuses on synthesizing superabsorbent material from polysaccharides, which are derived from environment-friendly raw materials like ligno-cellulosic agro-waste. Three ligno-cellulosic agro-waste fibres, namely banana, sisal and bagasse, have been taken for the present study, to synthesize natural superabsorbent polymer which are eco-friendly and bio-degradable. Cellulose has been extracted from sisal, bagasse and banana, of which cellulose yield has been high for banana fibres. Carboxy methyl cellulose (CMC) synthesized from the extracted cellulose is cross-linked with aluminium sulphate octadecahydrate to subsequently synthesize superabsorbent polymer from these agro-waste fibres. The sysnthecised CMC from all the three agro-waste fibres shows great reduction in immersion time; CMC from sisal shows the least immersion time of 2.67 s. Banana fibres have recorded the highest degree of substitution. The superabsorbent polymer synthesized from banana fibres has shown an increase in absorbency and swelling rate but  reduction in immersion time. This owes to the higher yield of cellulose and the higher degree of substitution attained in the case of banana fibres. This has been proved by chemical composition, SEM and FTIR analyses. This study helps in developing eco-friendly superabsorbent sanitary napkins.