PEER-REVIEWED ARTICLE bioresources.com Yahia & Sundman (2023). “Cellulose etherification,” BioResources 18(1), 161-174. 161 Replacing Benzyl Chloride with a Lignin-degradation Product in Cellulose Etherification Decreases the Melting Point Mohamed Yahia, a,b and Ola Sundman a, * A cellulose ether that is easier to melt than benzyl cellulose was produced from the lignin degradation product veratryl alcohol. Veratryl chloride and bromide were synthesized from the alcohol, and these two chemicals were used to react with Avicel® cellulose to form the novel cellulose ether veratryl cellulose (VC). Spectroscopic characterisation techniques ( 1 H NMR, FTIR) indicated the successful conversion of Avicel® cellulose to the cellulose ether VC, by both routes, at a degree of substitution of 1.4 to 1.6. Melting measurements of the VC samples showed a gradual softening from approximately 110 °C; the VC was melted below 200 °C. XRD analysis confirmed that the chemical treatments affect the degree of crystallinity. Size exclusion chromatography results showed that the products differ remarkably in molecular weight. The VC synthesized with veratryl chloride degraded almost twice as much as when veratryl bromide were used. The cellulose ethers were soluble in DMSO, DMAc, and CHCl3. DOI: 10.15376/biores.18.1.161-174 Keywords: Veratryl cellulose; Melting measurements; Cellulose ether; Degree of substitution; Characterisation techniques; Size exclusion chromatography Contact information: a: Department of Chemistry, Umeå University, Umeå, SE-90187, Sweden; b: Chemistry Department, Faculty of Science, Helwan University, 11795, Cairo, Egypt; * Corresponding author: ola.sundman@umu.se INTRODUCTION Although cellulose is a solid and valuable polymer, it has several drawbacks; for example, it is difficult to dissolve and cannot be melted (Lindman et al. 2010; Yang et al. 2014; Acharya et al. 2021). A commonly used strategy to circumvent these problems is to modify the chemical structure of the cellulose, and the products of such chemical modifications are collectively called cellulose derivatives (Zhang et al. 2019; Oprea and Voicu 2020; Liu et al. 2021; Mali and Sherje 2022). Cellulose derivatives are divided into two different groups: cellulose esters (e.g., cellulose acetate) and cellulose ethers (e.g., carboxymethyl cellulose) (Candido and Gonçalves 2016). Of these, cellulose ethers are dominating the market, with US$ 11.3 billion in 2021 to $ 14.62 billion in 2016 (Kukoyi 2016). Commercial cellulose ethers are used as thickening, stabilising, water-retaining, and dispersing agents in the building industry (Carraher and Charles 2003; Berglund et al. 2009). The change towards renewable recourses is desirable. However, cellulose etherification is achieved with the use of fossil-based chemicals, e.g., chloroacetic acid and ethyl chloride from fossil sources. The historically important benzyl cellulose (BC) is produced by the etherification of cellulose with petroleum-based benzyl chloride. This