Synthesis of superabsorbent (hydrogel) based on banana peel cellulose-acrylamide-carrageenan with microwave grafting method

Banana peel contains cellulose which has the potential to be a hydrogel raw material. This research developed a method of utilizing banana peel cellulose as a backbone which acrylamide was grafted onto it using a microwave to synthesize a superabsorbent hydrogel. This research studied the effect of the microwave grafting method and cellulose weight composition on the swelling degree behavior in the water media. The banana peels were purified by delignification using NaOH and NaClO solutions, and the dried powder obtained was used as cellulose. The aqueous mixture of cellulose and acrylamide was put into the microwave for the grafting process. The grafting was repeated with variations in the weight ratio of the cellulose-acrylamide. Hydroquinone was added to the mixture to stop the reaction. The solution was allowed to stand for the precipitation process. The solid precipitated was dried to produce Cellulose-g-PAM powder. A homogeneous solution of 2% carrageenan-Cellulose-g-PAM and carrageenan-cellulose was crosslinked physically using CaCl2 and KCl to form a bead gel. Based on FTIR spectrum, the acrylamide functional groups have been grafted on cellulose. The mass of banana peel cellulose influences the swelling degree. The swelling degree value was increased with the increase of the mass banana peel cellulose. Bead gel with the composition of Cellulose-g-PAM ratio (2:5) - carrageenan has the highest swelling degree value.