Synthesis of an Epoxy Monomer from Bio-Based 2,5-Furandimethanol and Its Toughening via Diels–Alder Reaction

Toughening Shape-Memory Epoxy Resins via Sacrificial Hydrogen Bond

The long fatigue life and stable performance in extreme environment of composites have been putting forward requirements for both high strength and toughness of epoxy matrix. However, for thermosets, promoting...

The Increasing Value of Biomass: Moving From C6 Carbohydrates to Multifunctionalized Building Blocks via 5-(hydroxymethyl)furfural

Recent decades have been marked by enormous progress in the field of synthesis and chemistry of 5-(hydroxymethyl)furfural (HMF), an important platform chemical widely recognized as the "sleeping giant" of sustainable chemistry. This multifunctional furanic compound is viewed as a strong link for the transition from the current fossil-based industry to a sustainable one. However, the low chemical stability of HMF significantly undermines its synthetic potential. A possible solution to this problem is synthetic diversification of HMF by modifying it into more stable multifunctional building blocks for further synthetic purposes.

Adhesive properties of bio-based epoxy resin reinforced by cellulose nanocrystal additives

The adhesive properties of a self-prepared bio-based epoxy resin with native cellulose nanocrystals (CNCs) are evaluated in this article. The porosity of actual CNCs is high. The most promising finding is the acquisition of high tensile modulus. The addition of CNC composites significantly increased the tensile modulus at lower wt.%, and the maximum crystallinity of CNCs was obtained. Bearing in mind the advantages of CNCs, scanning electron microscopy (SEM) showed a uniform distribution of concentrated CNCs. Clusters were formed at higher CNCs ratios, and the composite matrix content with high CNCs produced good expansion, low crystallinity, and increased elongation. Our analysis showed that the original CNCs were more evenly distributed in the self-prepared bio-based epoxy resin, which enhanced transformation, supported by improved dispersion of native CNCs. The presence of native CNCs greatly improved and enhanced the bonding performance of the bio-based epoxy resin in the interface area. Enhancing the mechanical properties of native CNCs has broad application prospects in environmental areas. This suggests that the widespread use of native CNCs in environmental engineering applications is feasible, especially in terms of adhesives properties.

Two-Step 3 D-Printing Approach toward Sustainable, Repairable, Fluorescent Shape-Memory Thermosets Derived from Cellulose and Rosin

Efficiently converting biomass into multifunctional polymerized materials is a challenge to effect high-valued utilization of biomass resources. A two-step 3 D-printing approach has been developed to fabricate a class of robust, fluorescent shape-memory thermosets from cellulose and rosin-based photosensitive 3 D-printing resin solution. The stereolithography 3 D printing was first performed to form the first crosslinked network by UV-induced chain-growth polymerization, which fixed the shape of thermoset. Subsequently, isocyanate was applied to react with hydroxy in the monomer to form the second crosslinked network by thermally induced step-growth polymerization. The formation of a dual-cure network, leading to phase separation and increased crosslinking density, could greatly improve the mechanical and thermal properties of 3 D-printed thermosets and endow them with thermally triggered shape-memory properties and excellent repairability. The 3 D-printed thermosets are found to have strong luminescence resulting from aggregation-induced emission originating from rosin. In addition, these 3 D-printed thermosets could degrade in the presence of NaOH aqueous solution and in situ achieved a range of flexible conductive hydrogels that have important potential application in the flexible electronic materials and smart photoelectric materials.

Probing the glass transition in reversible cross-linked polymer composites

Understanding the nature of glass transition is still a great challenge.

En route to CO2-containing renewable materials: catalytic synthesis of polycarbonates and non-isocyanate polyhydroxyurethanes derived from cyclic carbonates

The strategies and challenges in the preparation of fully renewable materials prepared from CO₂ and biomass enabled by catalysis are presented.

Sustainable bio-based furan epoxy resin with flame retardancy

A sugar-based bis-furan diepoxide (OmbFdE) was developed which imparted epoxy resins with excellent fire retardancy.

Green approaches in the synthesis of furan-based diepoxy monomers

Two eco-respectful, one-step synthetic routes for the preparation of a bio-based epoxy monomer derived from furan precursors are developed. The diglycidyl ester products are throughly characterized in terms of structure and thermal properties. Gathered results indicate that the two selected approaches allow the preparation of pure, furanic diglycidyl ester, which represents a viable bio-based alternative to its petrochemical aromatic counterpart.

Two eco-respectful, one-step synthetic routes for the preparation of a bio-based epoxy monomer derived from furan precursors are developed.