# 2-Methoxy-4-Vinylphenol as a Biobased Monomer Precursor for Thermoplastics and Thermoset Polymers
## 3 Results
### Thermoplastic Applications  
It has been shown that the styrene-like monomer 2-methoxy-4-vinylphenol (MVP) can be derived from FA through decarboxylation [29; 30]. However, little work has been reported in the literature using MVP as a precursor to new biobased functional monomers that can undergo radical polymerization [31; 34]. MVP contains a terminal double bond and a phenol, which enable further functionalization (Scheme 1). Both functional groups are highly reactive, which could lead to unfavorable autopolymerization, e.g., due to the radical scavenging effect, as shown for other phenolics [36]. Withstanding the fact that the double bond should remain intact to subsequently participate in free-radical polymerization, the phenolic group was functionalized to prepare biobased derivatives. Due to its highly reactive character, MVP was functionalized within the timeframe it was considered stable (Figure S3). The first MVP derivative was 2-(2-methoxy-4-vinylphenoxy)acetate (MVP-AcOMe, Figures S4 and S5), an aliphatic modification resulting from the reaction between MVP and methyl bromoacetate (MeBrAc, Scheme 1). The second derivative was 1-(benzyloxy)-2-methoxy-4-vinylbenzene (MVP-Bz, Figures S8 and S9), an aromatic modification accomplished by the reaction with benzyl bromide (BzBr, Scheme 1). In addition to these hydrophobic derivatives, a hydrophilic modification of MVP, referred to as 2-(2-methoxy-4-vinylphenoxy)acetic acid (MVP-AcOH, Figures S6 and S7), was prepared by using MVP-AcOMe as the intermediate (Scheme 1). The yield for all reactions was higher than 70%, suggesting that MVP can act as a platform to yield polymerizable derivatives with hydrophobic and hydrophilic characteristics. Moreover, their chemical composition is in line with other lignin monomers and C-O-linked fossil-based commercial polymers, making them applicable for replacing fossil-based monomers (Figure S39) [37]. Although the monomers obtained from the MVP platform were derived from natural resources, the use of halogenated reagents employed in their synthetic routes in this study was hypothesized to impact their overall ecofriendly character. Hence, atom efficiency (AE) [38], environmental factor (E) [39; 40], and biobased carbon content (BBCC) [41] (Table S11) were considered. AE is a measure of the efficiency of a reaction, expressed as a percentage. Hence, a higher AE percentage denotes greater efficiency [38]. The AEs for MVP, MVP-AcOMe, and MVP-Bz (-75%) were greater than that for MVP-AcOH (64%), because the latter is the result of a two-step process, with the MVP-AcOMe being the intermediate. Additionally, E expresses the environmental impact of a synthetic process by determining the waste generated [39; 40]. The ideal value for E is 0 (no waste); a higher value of E denotes a more negative environmental impact of a process. The E-values for the synthetic approaches used (-19) were within range of other processes involving lignin-derived monomers (Table S12) [42] except for MVP-AcOH (-135), due to the two-step procedure and number of solvents used. Moreover, a closer value of BBCC to 100% denotes a greater amount of biobased carbon in the final product [41]. For all monomers, except for MVP-Bz, the BBCC was higher than 75%, which is higher than other eugenol-derived functional monomers (Table S12) [41]. This is because the substituting group used in the case of MVP-Bz had the same number of carbons as MVP, thus reducing the overall BBCC. The biobased monomers were initially polymerized via solution polymerization to prepare the appropriate homopolymers. The monomer conversion was followed by \({}^{1}\)H-NMR, and the kinetics are shown in Figure S14. In Figure S14, it can be seen that all biobased homopolymers exhibited similar apparent polymerization rates; however, MVP-Bz exhibited the lowest conversion rate among the investigated monomers, i.e., 75% compared to 90%. This may have been due to the bulkiness of the modifying side-group, which would have enhanced the steric hindrance during polymerization of the final polymer [43].