## 1 Introduction  
In the past 20 years, the focus in the field of research on polymeric products has shifted toward the synthesis and application of polymers that are both bio-based and recyclable [1]. In the near future, this will become even more important due to the growing scarcity of petroleum as a feedstock for current conventional polymeric products. Various publications describe the successful substitution of petroleum-based components with bio-based analogs [2; 3; 4; 5]. However, to produce a sustainable product it is of vital importance not only to focus on the feedstock materials but also to look at what is done with the product after utilization (i.e., the waste generated at end of life). It is well-known that the recyclability of polymeric systems in general, and thermosets in particular, is often still a challenge [6; 7]. The permanent shape and structure imparted by the covalent cross-links severely limit the reusability of these polymers [8], which undergo degradation (as opposed to the desired softening or melting) upon heating. There is no viable, straightforward replacement for thermoset materials as the (densely) cross-linked networks of these materials impart superior barrier and mechanical properties compared to their (non-cross-linked) thermoplastic analogs. Due to this durable nature, thermosets are often used in a wide variety of applications such as composites, adhesives, and coatings. The downside of these strong, (densely) cross-linked networks, however, is that thermosets do not possess the chain mobility that thermoplastics often do. This severely reduces their (re)processability and intrinsic capability to be repaired [9]. As a consequence, many thermoset resins cannot be recycled after usage and eventually end up in landfills. In recent years, the laws for waste management have become stricter, placingever more emphasis on the production of recyclable products. Preventing waste at the source of manufacture is the most desired way to manage waste [10]. There are various ways of interpreting these goals. Enabling recyclability of previously unrecyclable materials reduces the demand for the production of new materials, effectively preventing waste at the source. For polymer thermosets, one of the options for achieving this is to introduce thermoreversibility into the polymeric material, namely as a characteristic feature of the cross-linking reaction. This thermoreversibility gives rise to the possibility of remolding and reshaping the thermoset material by applying heat while optimally retaining the mechanical properties of the material. One way to introduce thermoreversible cross-linking into a polymeric system is to incorporate moieties that are capable of undergoing (reversible) Diels-Alder interactions. Once incorporated into the polymer matrix, these moieties can act as cross-linking points. The general Diels-Alder mechanism consists of a \((4\pi+2\pi)\) cycloaddition reaction between a conjugated diene and an alkene as dienophile to form a (substituted) cyclohexene system [11; 12; 13]. This cycloaddition leads to the formation of covalent bonds at lower temperatures (generally at around 50 \({}^{\circ}\)C and below) through the Diels-Alder (DA) reaction, whereas the reaction being an equilibrium, at higher temperatures (at approximately 120 \({}^{\circ}\)C and above) the covalent bonds break and the original diene and dienophile groups are obtained through the retro-Diels-Alder (rDA) reaction [14]. The first preparation of thermally reversibly cross-linked polymers employing DA chemistry was reported by [PERSON] et al. [6; 15]. A furan-functionalized polymer is described, which forms thermally reversible networks with multiple maleimides. A large number of diene and dienophile couples can be used in DA chemistry, where electron-pushing and electron-withdrawing substituents in the diene and dienophile greatly influence the reactivity [16].