Sulfonation of waste cassava to produce superabsorbent.

Abstract

Onggok is a waste product of tapioca industries which has low economical value. The aim of this research is to find a way to increase the added value of onggok by transforming it into a superabsorbent. The making of superabsorbent from onggok was preparated through sulfonation and preceded by oxidation. In this experiment the oxidation was carried out with 3 levels of reaction time, i.e. 210, 270, and 330 minutes. While sulfonation was carried out with 3 levels of concentration of NaHSO3, that are 15, 20 and 35 g and 3 levels of sulfonation time of 120, 180 and 240 minutes. The absorption capacity of the product was evaluated through their absorption capacity, carried out by immersing the product for 4 hours in a known volume of distill water. Its absorptive capacity is calculated based on its sample weight increases due to water absorption. The results show that the highest absorption capacity was indicated by the sample with 270 minutes of oxidation, 240 minutes of sulfonation time and 20 g of NaHSO3. Its absorption capacity was 38.54 g/g. The result of FTIR spectroscopic study and sulfur analysis indicated that bisulfite ions are incorporated into cellulose molecules of onggok