A Critical Review of Sustainable Vanillin-modified Vitrimers: Synthesis, Challenge and Prospects

Abstract

Nearly 90% of thermosets are produced from petroleum resources, they have remarkable mechanical characteristics, are chemically durable, and dimensionally stable. However, they can contribute to global warming, depletion of petroleum reserves, and environmental contamination during manufacture, use, and disposal. Using renewable resources to form thermosetting materials is one of the most crucial aspects of addressing the aforementioned issues. Vanillin-based raw materials have been used in the industrial manufacturing of polymer materials because they are simple to modify structurally. Conversely, traditional thermosetting materials as a broad class of high-molecular-weight molecules are challenging to heal, decompose and recover owing to their permanent 3-D crosslinking network. Once the products are damaged, recycling issues could arise, causing resource loss and environmental impact. It could be solved by inserting dynamic covalent adaptable networks (DCANs) into the polymer chains, increasing product longevity, and minimizing waste. It also improves the attractiveness of these products in the prospective field. Moreover, it is essential to underline that increasing product lifespan and reducing waste is equivalent to reducing the expense of consuming resources. The detailed synthesis, reprocessing, thermal, and mechanical characteristics of partly and entirely biomass thermosetting polymers made from vanillin-modified monomers are covered in the current work. Finally, the review highlights the benefits, difficulties, and application of these emerging vanillin-modified vitrimers as a potential replacement for conventional non-recyclable thermosets.

Vanillin-Based Epoxy Vitrimers: Looking at the Cystamine Hardener from a Different Perspective

“…Their seminal article described materials with fast reprocessing and paved the way to multiple reports based on this dynamic hardener. ,− The combination of bio-based monomers with vitrimer properties and more specifically disulfide exchanges were also investigated. , In this context, the use of a vanillin building block has attracted considerable attention owing to its large availability and its (1,4) phenol/aldehyde functionalities that can be directly reacted with amine (aldehyde) or chemically modified to prepare various reactive building blocks . For a more exhaustive literature on vanillin-based vitrimers, the reader is directed to a recent review and some other related reports. − For instance, Genua and coworkers reported the formulation of vitrimer resins synthesized from vanillin and phloroglucinol precursors derived from naturally occurring feedstocks, but with petro-based 4AFD as a curing agent . In view of replacing 4AFD by a more environmentally friendly analogue, the development of bio-based dynamic hardeners also attracted significant attention.…”

“… 25 , 26 In this context, the use of a vanillin building block has attracted considerable attention owing to its large availability and its (1,4) phenol/aldehyde functionalities that can be directly reacted with amine (aldehyde) or chemically modified to prepare various reactive building blocks. 27 For a more exhaustive literature on vanillin-based vitrimers, the reader is directed to a recent review 28 and some other related reports. 29 − 31 For instance, Genua and coworkers reported the formulation of vitrimer resins synthesized from vanillin and phloroglucinol precursors derived from naturally occurring feedstocks, but with petro-based 4AFD as a curing agent.…”

Lignin-Based Covalent Adaptable Network Polymers─When Bio-Based Thermosets Meet Recyclable by Design

“…131 Furthermore, CANs have attracted significant interest from the 3D printing industries due to their ability to form strong but still reversible bonds between the printed layers (Figure 8a). In addition to 3D printing, the application of CANs can be expanded to dental restorative resins, 132 composites and coatings, 133 sports equipment, 134 and electronics 134 (Figure 8b). However, more efforts are still needed in order to obtain CANs with properties that match those of robust fossil-based thermosets, being this main threat of lignin-based CANs.…”

From vanillin to biobased aromatic polymers

“…103 The introduction of dynamic covalent bonds can induce network rearrangements, emerging as a sustainable alternative for developing recyclable thermosets. 104 This also provides crosslinked polymers with desirable functionalities, such as self-healing, weldability, and reconfigurability, thus prolonging the service life of the materials they are used in. Vanillin offers additional possibilities because its aldehyde group can form dynamic imine linkages by condensation with amines or dynamic acetal linkages by condensation with polyols.…”