Production of lignocellulose nanofibril (LCNF) from high yield pulps by hydrated deep eutectic solvents (DES) pretreatment for fabricating biobased straw

In this study, lignocellulose nanofibril (LCNF) was prepared from high yield pulps (HYP) by hydrated choline chloride-ethylene glycol (CE) in combination with mechanical treatment. TEMPO-oxidized cellulose nanofibrils (TO-CNF), LCNF and LCNF/TO-CNF composite films were then produced by a solution casting method. The yield of HYP reached up to 89.1 % with a lignin retention rate of 23.9 % under the optimal reaction condition (100 % DES). The obtained LCNF/TO-CNF composite film demonstrated several advantageous properties over LCNF and TO-CNF films including: 1) excellent mechanical properties, 2) higher hydrophobic property, and 3) improved thermal stability. Compared to composite straw by reconstructing the cellulose-lignin reinforced composite structure in previous reports, in this study, the fabricated LCNF/TO-CNF composite straw from the as-prepared film by a one-step process without complicated procedures, achieved comparable high mechanical performance and water resistance. Overall, this LCNF/TO-CNF composite film with appropriate performance is envisioned as a promising candidate to replace conventional plastics-based materials to produce single-use straw.