Preparation of Novel Aromatic‐Aliphatic Poly(ketone ester)s through Condensation of Biomass‐Derived Monomers

Cellulose levulinate ester as a robust building block for the synthesis of fully biobased functional cellulose esters

Facile modification of cellulose or cellulosic derivatives is one of the important strategies to prepare materials with targeted properties, multifunctionality, thus extending their applications in various fields. Cellulose levulinate ester (CLE) has the structural advantage of acetyl propyl ketone moiety pendant, on which fully biobased cellulose levulinate ester derivatives (CLEDs) have been successfully designed and prepared via aldol condensation reaction of CLE with lignin-derived phenolic aldehydes catalyzed by DL-proline. The structure of CLEDs are featured by a phenolic α,β-unsaturated ketone structure, thus endowing them with good UV absorption properties, excellent antioxidant activity, fluorescence properties and satisfactory biocompatibility. The utility of this aldol reaction strategy, together with the facile tunable substitution degree of cellulose levulinate ester and the diversity of aldehydes, can provide potentially a large spectrum of structurally diverse functionalized cellulosic polymers and create new avenues to advanced polymeric architectures.

Eugenol-derived organic liquids as an in situ CO2 capturing and conversion system for Eugenol-based polycarbonate synthesis

The significant development of catalytic biomass conversion has provided a large library of chemicals ready for subsequent upgrading to polymerisable monomers for the design and preparation of sustainable polymers. In this study, hydroxyethylation of eugenol by using green ethylene carbonate as alkylation reagent and cheap tetrabutylammonium iodide ionic liquids as green solvents and catalysts produced 2-(4-allyl-2-methoxyphenoxy)ethan-1-ol with a 85% yield,  which could be used to construct an in situ CO 2 capture and conversion system by taking the reversible chemistry of alcoholic compounds with CO 2 in the presence of superbases, on which α,ω-diene functionalized carbonate monomers were successfully prepared and were applied in  thiol-ene click and acyclic diene metathesis polymerisation (ADMET), producing a series of poly(thioether carbonate)s and unsaturated aromatic aliphatic polycarbonates with moderate molecular weights and satisfactory thermal properties. The structures of the formed CO 2 reversible ILs, the polymerisable monomers and the corresponding polymers were fully characterized by various technologies.

Sustainable Aromatic Aliphatic Polyesters and Polyurethanes Prepared from Vanillin-Derived Diols via Green Catalysis

The design and preparation of polymers by using biobased chemicals is regarded as an important strategy towards a sustainable polymer chemistry. Herein, two aromatic diols, 4-(hydroxymethyl)-2-methoxyphenol and 2-(4-(hydroxymethyl)-2-methoxyphenoxy)ethanol, have been prepared in good yields through the direct reduction of vanillin and hydroxyethylated vanillin (4-(2-hydroxyethoxy)-3-methoxybenzaldehyde) using NaBH4, respectively. The diols were submitted to traditional polycondensation and polyaddition with acyl chlorides and diisocyanatos, and serials of new polyesters and polyurethanes were prepared in high yields with moderate molecular weight ranging from 17,000 to 40,000 g mol-1. Their structures were characterized by 1H NMR, 13C NMR and FTIR, and their thermal properties were studied by TGA and differential scanning calorimetry (DSC), indicating that the as-prepared polyesters and polyurethanes have Tg in the range of 16.2 to 81.2 °C and 11.6 to 80.4 °C, respectively.