Catalytic deep eutectic solvent for levoglucosenone production by pyrolysis of cellulose

Controlled Enzymatic Synthesis of Polyesters Based on a Cellulose-Derived Triol Monomer: A Design of Experiment Approach

Regioselective enzymatic polycondensation of the bio-based cellulose derived polyol, Triol-citro, and dimethyl adipate using Candida antarctica Lipase B (CaLB) was investigated. A Design of Experiment approach with MODDE® Pro 13 was used to determine important factors in the branching behavior of this polymer, and reactant ratio, temperature, reaction time and enzyme wt % were the studied factors. Multifunctional polyesters with pendant hydroxy groups were synthesized and fully characterized using 2D NMR techniques to determine degree of branching. Branching was minimal, with a maximum of 16 % observed, and monomer ratio, temperature and reaction time were all determined to be significant factors. In this work, Mn of up to 13 kDa were achieved, while maintaining degree of branching below 15 %, resulting in a linear polyester with the potential to be further functionalized.

Fast Pyrolysis of Cellulose and the Effect of a Catalyst on Product Distribution

Fast pyrolysis of microcrystalline cellulose (MC) was carried out by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The effects of temperature, time, and a catalyst on the distribution of the pyrolysis products were analyzed. The reaction temperature and time can significantly affect the types and yields of compounds produced by cellulose pyrolysis. A pyrolysis temperature of 500-600 °C and pyrolysis time of 20 s optimized the yield of volatile liquid in the pyrolysis products of cellulose. In all catalytic experiments, the relative contents of alcohols (1.97%), acids (2.32%), and esters (4.52%) were highest when K₂SO₄ was used as a catalyst. HZSM-5 promoted the production of carbohydrates (92.35%) and hydrocarbons (2.20%), while it inhibited the production of aldehydes (0.30%) and ketones (1.80%). MCM-41 had an obvious catalytic effect on cellulose, increasing the contents of aldehydes (41.58%), ketones (24.51%), phenols (1.82%), furans (8.90%), and N-compounds (12.40%) and decreasing those of carbohydrates (5.38%) and alcohols (0%).

Magnetic porous cellulose surface-imprinted polymers synthetized with assistance of deep eutectic solvent for specific recognition and purification of bisphenols

Magnetic porous cellulose molecularly imprinted polymers-based bisphenols have been developed using Fe₃O₄ as the magnetic material, a deep eutectic solvent as the assisted solvent, and N-isopropylacrylamide as the functional monomer. The resulting magnetic porous cellulose molecularly imprinted polymers were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometry, thermal gravimetric analysis, and Brunauer-Emmett-Teller analysis. Moreover, the adsorption properties of the magnetic porous cellulose molecularly imprinted polymers toward bisphenol A, bisphenol F, and bisphenol AF were investigated using static, dynamic, and selective adsorption experiments. The introduction of porous cellulose materials significantly improves the capabilities of the material. The adsorption capacity, mass transfer efficiency, and selectivity of the magnetic porous cellulose molecularly imprinted polymers toward bisphenol A were 5.9, 4.0, and 4.4 times those of traditional molecularly imprinted polymers. Moreover, the adsorption stability of the magnetic porous cellulose molecularly imprinted polymers was investigated under different temperature and pH conditions. The adsorption characteristics of the magnetic porous cellulose molecularly imprinted polymers toward the target molecules were investigated using adsorption isotherm, kinetic, and thermodynamic models. Hydrogen bonding is the main interaction formed between the magnetic porous cellulose molecularly imprinted polymers and the target molecules. Magnetic porous cellulose molecularly imprinted polymers have great application value with excellent stability and reusability. Finally, the combination of the magnetic porous cellulose molecularly imprinted polymers and high-performance liquid chromatography or ultra-performance liquid chromatography-mass spectrometry was successfully used for the purification and detection of bisphenols in milk (1.349 ng/mL bisphenol F and 3.014 ng/mL bisphenol AF), canned fruits (1129 ng/mL bisphenol A, 10.11 ng/mL bisphenol F, and 91.87 ng/mL bisphenol AF), and fish (11.91 ng/mL bisphenol AF) samples. Furthermore, the magnetic porous cellulose molecularly imprinted polymer method is more selective, sensitive, and accurate than the traditional precipitation method.