Hydrogel film synthesis for biowrapping via a single-cycle freeze-thaw process untilizing carboxymethyl cellulose/microcrystalline cellulose and citric acid as crosslinker

¹ Department of Agroindustrial Technology, Faculty of Agriculture, Lambung Mangkurat University, Banjarbaru Jl A Yani KM 36 Banjarbaru Kalimantan Selatan, Indonesia, 70714
² Department of Agroindustrial Technology, Faculty of Agricultural Technology, Gadjah Mada University, Jl. Flora No 1 Bulaksumur Yogyakarta, Indonesia, 55281

^* Corresponding author: susi_tip@ulm.ac.id

Abstract

Crosslinking will be critical in producing the desired hydrogel with good absorption and high mechanical strength properties. Despite chemical crosslinking, the physical technique of freeze-thaw has reduced chemical use. This research determined the appropriate formulation of CMC/MCC and citric acid concentration using the freeze-thaw method of one cycle and drying to produce hydrogel with high water absorption and mechanical strength. The research findings showed that the hydrogel film created for biowrapping must have high absorption capacity and mechanical strength. This was achieved using a CMC/MCC ratio of 90:10 and a 5% citric acid crosslinker concentration. The hydrogel film showed a swelling capacity of 322.72%±9.32 at pH 7, a gel fraction of 9.87%±0.26, and a dry gel rehydration ability of 466.96%±30.41. The tensile strength for the CMC/MCC 90:10 ratio was 0.303±0.001 MPa, and the strain at F max was 48.74%±2.42. The water vapor permeability level was also measured at 3.688x10^-5 g/m.Pa.24h. Increasing the MCC to CMC ratio to 50:50 led to a decrease in the water vapor permeability of the hydrogel film.