Sintesis Wet Strength Agent (WSA) Berbasis Selulosa melalui Reaksi antara Selulosa Dialdehida dan Dietilamina

Abstract

Cellulose is an abundant biopolymer that can be selectively oxidized into dialdehyde cellulose (DAC) using sodium periodate (NaIO₄). The aldehyde groups in DAC enable further reactions with amines, including diethylamine, providing the potential to produce modified materials suitable for use as wet strength agents (WSA). This study aims to synthesize DAC from oil palm empty fruit bunch (EFB) cellulose, modify the DAC using diethylamine, and evaluate its application as a WSA in papermaking. DAC was synthesized through periodate oxidation with reaction times of 3, 6, and 9 hours. The best result was obtained at 9 hours, yielding an oxidation degree of 56.55% and a carbonyl content of 13.3%. FT-IR analysis revealed the appearance of an aldehyde C=O band at 1748 cm⁻¹, confirming the successful formation of DAC. The subsequent reaction between DAC and diethylamine produced a modified material characterized by a band at 1664 cm⁻¹, indicating the formation of iminium species (C=N+). The resulting product has a nitrogen content of 4.76%. SEM analysis showed rough and aggregated particle surfaces, while PSA analysis demonstrated a narrow particle size distribution with a dominant size of 240–250 nm. The DAC–diethylamine product was then applied as a WSA in the fabrication of 60 g/m² paper. The resulting paper exhibited a dry tensile strength of 310 N/m and a wet tensile strength of 70 N/m. Overall, the modified product was able to enhance the mechanical strength of the paper, although its performance has not yet reached that of commercial WSAs.