Table 1.

Vanillin-based monomers used in polymer synthesis

No.	Monomers and their derivatives	Polymer	Propertiesa	Potential application	Reference
Polyols
1		Polycarbonate Epoxy	Polycarbonate: Tg = 99°C–106°C T5 = 336°C–372°C Epoxy: Tg (E″) = 100°C–123°C Tg (Tanδ) = 107°C–132°C E' = 2.29–3.02 GPa T5 = 337°C–363°C Lower estrogen activity than BPA	Direct replacement for BPA, adhesives	Koelewijn and Hernandez et al. 30,31
2		Polyester	Tg = 42°C–142°C Td = 272°C–342°C	Fiber	Wu et al. 32
3		Epoxy Polyester	Recyclability Epoxy: Tg = 74°C–119°C E' = 1.15 GPa (neat) – 7.6 GPa (reinforced with CNF) Epoxy2: T5 = 278°C Tg = 164°C Tensile modulus = 3131 MPa Tensile strength = 85 MPa Polyester: Tg = 20°C–64°C T5 = 320°C–345°C E' (20°C) = 756–1991 MPa	Fiber Polyesters: textile, food packaging	Mankar, Koike, Mankar, and Subbotina et al. 33,34,35,36
4		Poly(vanillin) oxalate	Biodegradable, biocompatible	Medical devices, drug delivery	Kwon et al. 37
5		Polyesters Epoxies Polyurethanes	Polyesters: Tg = -5–139°C E' = 0.1–8.1 GPa T5 = 270°C–347°C Potential phenolic functionality Epoxies: Tg = 138°C–198°C Tα = 155°C–200°C E' = 1.7–2.4 GPa T5 = 275°C–336°C Potential flame retardancy Polyurethanes: T5 = 330°C–342°C Young’s modulus = 8.0–9.7 MPa	Polyesters: Epoxies: potential bio-based alternative for DGEBA (bisphenol A diglycidyl ether)	Llevot, Savonnet and Gang et al38,39,40
6		Epoxies	Tg = 132°C, 97°C Tα = 154°C, 106°C E' (30 C) = 1.2, 1.5 GPa Td = 338°C, 361°C CY = 20%, 19%	To replace BPA-based epoxies	Fache et al. 41
Dicarboxylic acids/diesters
7	7a: R = H, n = 2 7b: R = CH3, n = 4	Polyesters	7a: Tg = 55°C–69°C Tm = 212°C–260°C 7b: Tg = −4.4°C–13°C Tm = 70.1°C T5 = 360°C–390°C E' = 493–581 MPa Tensile strength = 5.0–7.0 MPa Strain at break = 12.7–43.7% Young’s modulus = 66.2–99.7 MPa	Fibers	Lange and Pang et al. 42,43
8		Polyesters	Tg = −10.3 to −12.7°C Tm = 24.5, 48.5°C T5 = 335°C–339°C E' = 283 MPa Tensile strength = 4.1 MPa Strain at break = 22.8% Young’s modulus = 50 MPa	Biodegradable polyesters	Pang et al. 43
9	R = (CH2)nCH3; n = 0,1,2 & 3	Polyesters	Tg = 19°C–89°C T5 = 340°C–390°C Tensile strength = 0.34–15.8 MPa Elongation at break = 55–1880% Young’s modulus = 0.13–1 MPa	Packaging	Enomoto et al. 44
Hydroxy acids/acetylated hydroxyl acids
10		Polyesters	Tg = 73°C Tm = 234°C Comparable characteristics to PET	Textiles	Mialon et al. 45
11	n = 0, 2, 3, 6, & -CH(CH3)CH2-	Polyesters	Comparable characteristics to commercial polyesters such as PET, PBT depending on aliphatic spacers (n)	Textiles	Mialon, Zamboulis and Gioia et al. 46,47,48

^aT_g = glass transition temperature (measured by differential scanning calorimetry), T_g(E″) = glass transition temperature (measured from the loss modulus curve by dynamic mechanical analysis), T_g(Tanδ) = glass transition temperature (measured from the Tanδ curve by dynamic mechanical analysis), T_m = melting temperature, T₅ = decomposition temperature at 5% mass loss, T_d = temperature at the maximum degradation rate, T_α = alpha transition temperature, E’ = storage modulus, E’’ = loss modulus, CY = char yield.