Enhanced conversion of rosin to polymerized rosin with reusable Brønsted acid deep eutectic solvent

With the depletion of non-renewable resources and the increasingly serious environmental problems, the production of high value-added polymer materials using renewable resources as raw materials had aroused great interest. Deep eutectic solvent (DES)-[ChCl][TfOH]2 2 (prepared by choline chloride (ChCl) and trifluoromethanesulfonic acid (TfOH)), with suitable acid strength (H0=0.98) 0 =0.98) and active hydrogen, had been successfully used for enhanced conversion of rosin to polymerized rosin efficiently, under the conditions of rosin =15 g, m DES : m rosin = 30 %, T=110 degrees C =110 degrees C and t=9 =9 h, polymerized rosin with high softening point (150.40 degrees C) and low acid value (124.21 mg KOH/g) could be produced efficiently. [ChCl][TfOH]2 2 required no special treatment then could be reused for 5 times without significant loss of catalytic performance, on this basis, the green synthesis technology of polymerized rosin under DES system was given, not only promoted the further application of polymerized rosin, but also realized the high value-added utilization of renewable resource rosin. In addition, the formation mechanism of DES was systematically explained through DFT calculation, the reaction mechanism of rosin polymerization over [ChCl][TfOH]2 2 was explored, which could provide theoretical basis for further research.