Effect of Treatment Time on Deep Eutectic Solvent Treatment of Scots Pine Wood

Abstract

Aim of study: The influence of the treatment time (1 hour, 2 hours, and 3 hours) on the deep eutectic solvent (DES) treatment of Scots pine (Pinus sylvestris L.) wood is investigated in this study. Area of the study: Determination of DES performance on the Scots pine wood chemical structure. Material and methods: Choline chloride (ChCl) and lactic acid (LA) mixture with molar ratio of 1:10 (w:w) was used as a DES solvent. Treatments were carried out in an autoclave at 121 degrees C. The effects of DES treatment on the properties of wood and lignin samples of Scots pine were determined according to the relevant standards. Main results: The delignification ratio, lignin purity, and lignin yield in the 3h -treated sample were determined to be 79.78%, 86.43%, and 82.48%, respectively. The crystallinity index (CrI) was increased from 55.87% to 71.58% with 3 h DES treatment. Brunauer-Emmett-Teller (BET) analysis results showed that the surface area of the sample increased with 3-h DES treatment (from 3.095 m2/g to 3.621 m2/g). The 1 -hour DES -treated sample yielded the lightest colored lignin (L*: 71.62). Research highlights: Treatment time of Scots pine wood during DES treatment has a significant effect on the wood and lignin properties.