Sintesis Basa Schiff melalui Kondensasi Selulosa Dialdehida dari Tandan Kosong Kelapa Sawit dengan Etilendiamina sebagai Wet Strength Agent (WSA)

Abstract

Cellulose was isolated from empty palm bunches (TKKS) using a combination of 3.5% HNO3, 2% NaOH, Na2SO3, 1.75% NaOCl, and 10% H2O2. A total of 18.167 g of cellulose was obtained, which corresponds to 24.22% of the initial weight. The cellulose underwent oxidation using NaIO4 at a mass ratio of 1:2.1, with reaction times of 3, 6, and 9 hours at 85°C to produce cellulose dialdehyde. The formation of cellulose dialdehyde was characterized by a brick-red precipitate in Fehling's reagent and increased solubility in hot water. The cellulose dialdehyde (SDA) produced exhibited the highest oxidation degree of 56.55% and a carbonyl content of 13.3%. FT-IR analysis revealed a vibrational peak at a wavenumber of 1674.68 cm⁻¹, indicating the presence of the C=O aldehyde group. Scanning Electron Microscopy (SEM) analysis showed that the fiber surface of the cellulose dialdehyde was smoother and more irregular compared to cellulose. Particle Size Analysis (PSA) indicated a decrease in the average fiber diameter to 307 ± 83 nm. The Schiff base was synthesized through the condensation reaction of the amine group of ethylenediamine with the cellulose dialdehyde (SDA) obtained from the oxidation of TKKS cellulose using NaIO4. The resulting Schiff base contained a nitrogen content of 0.3092%. The formation of the Schiff base was further supported by FT-IR analysis, which showed a spectrum with a vibrational peak at a wavenumber of 1650.57 cm⁻¹, indicating the presence of imine bonds (-C=N-). SEM analysis depicted a relatively smooth surface for the Schiff base fibers, attributed to the opening of anhydroglucose unit (AGU) structures and damage to the organized fiber structure. PSA analysis showed a decrease in the average fiber diameter to 96 ± 21 nm.The direct application of Schiff base onto paper as a cellulose-based wet strength agent (WSA) has demonstrated a tensile strength of 7.549 kN/m and a tensile index of 12.582 Nm/g. According to SNI 8218:2015, these results indicate a performance that surpasses the established standard.