Mechanical Properties of Pulp Delignified by Deep Eutectic Solvents

Mechanical properties were evaluated for pulp delignified by four deep eutectic solvents (DES). The DES systems were based on choline chloride and lactic acid (1: 9), oxalic acid: dihydrate (1: 1), malic acid (1: 1), and the system alanine: lactic acid (1: 9). The results indicated that the type of DES system used influenced the delignified pulp's mechanical properties including tensile, burst and tear indexes, tensile length, and stiffness. The most suitable DES systems were choline chloride: malic acid (1: 1) and alanine: lactic acid (1: 9), which achieved the best aforementioned mechanical properties compared to the other DES systems. The weakest performance in the process of pulp delignification was the system with choline chloride and oxalic acid dihydrate (1: 1).