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Review

Recent Advances in Renewable Polymer Production from Lignin-Derived Aldehydes

by
Nahyeon Lee
1,†,
Yong Tae Kim
2,† and
Jechan Lee
1,3,*
1
Department of Energy Systems Research, Ajou University, 206 Worldcup-ro, Suwon 16499, Korea
2
C1 Gas & Carbon Convergent Research Center, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Daejeon 34114, Korea
3
Department of Environmental and Safety Engineering, Ajou University, 206 Worldcup-ro, Suwon 16499, Korea
*
Author to whom correspondence should be addressed.
†
Designates the co-first authors who contributed equally to this work.
Polymers 2021, 13(3), 364; https://doi.org/10.3390/polym13030364
Submission received: 10 January 2021 / Revised: 21 January 2021 / Accepted: 21 January 2021 / Published: 24 January 2021
(This article belongs to the Special Issue Green Chemistry in Polymer Science and Sustainable Polymers)
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Abstract

:
Lignin directly derived from lignocellulosic biomass has been named a promising source of platform chemicals for the production of bio-based polymers. This review discusses potentially relevant routes to produce renewable aromatic aldehydes (e.g., syringaldehyde and vanillin) from lignin feedstocks (pre-isolated lignin or lignocellulose) that are used to synthesize a range of bio-based polymers. To do this, the processes to make aromatic aldehydes from lignin with their highest available yields are first presented. After that, the routes from such aldehydes to different polymers are explored. Challenges and perspectives of the production the lignin-derived renewable chemicals and polymers are also highlighted.

1. Introduction

Lignocellulosic biomass has been regarded as the renewable alternative carbon that potentially replaces fossil fuel resources [1,2,3,4,5]. It consists mainly of cellulose, hemicellulose, and lignin [6]. Lignin is a heterogeneous aromatic biopolymer, which comprises 15–30% of the weight of lignocellulosic biomass and an integral part of cell walls of terrestrial plants [7,8]. Lignin has aromatic structure; hence, it is considered a considerable renewable carbon source [9,10,11,12]. Nevertheless, the utilization of lignin has been limited to energy recovery. For example, most biorefinery processes degrade lignin, involving breakage of unstable ether bonds (e.g., β-O-4 linkage) and C–C bond formation of reactive intermediates via their condensation [13,14,15,16]. The resultant degraded lignin is usually incinerated for heat and power production because it is hard to be depolymerized [17,18]. In order to enhance sustainability and economics of biorefinery of using lignocellulosic biomass as a raw material, the effective utilization of lignin is crucial [19].
There have recently been efforts to search suitable renewable raw materials for polymer production. In particular, the development of bio-based polymers from lignin-derived monomers has gained great interest [20,21]. Within these contexts, this review provides up-to-date summary and knowledge of bio-based polymers synthesized from lignin-derived aromatic aldehyde compounds. To this end, we first discuss a variety of methods to convert lignin into aromatic aldehydes (i.e., syringaldehyde and vanillin). Various routes from these substances to bio-based polymers are then outlined. At last, present challenges and prospects of the processes are discussed.

2. Production of Aromatic Aldehydes from Lignin

Aerobic oxidation of lignin under alkaline conditions selectively produces aromatic aldehydes such as syringaldehyde and vanillin [22]. Vanillin is commercially produced via alkaline aerobic oxidation of sulfonated lignin [23,24]. Alkaline oxidation of lignin has been extensively investigated mostly using condensed lignin feedstocks such as Kraft lignin [25,26,27,28,29] and sulfonated lignin [29,30,31,32,33]. For example, different research groups conducted studies into the effect of reaction parameters (e.g., temperature, O2 pressure, and NaOH concentration) on aerobic oxidation of Kraft lignin and sulfonated lignin [34,35,36]. Table 1 lists the results of alkaline aerobic oxidation of different lignins. Figure 1 illustrates reactions involved in aerobic oxidation of lignin to aromatic aldehydes (e.g., vanillin).
Earlier studies on alkaline aerobic lignin oxidation used lignins with highly modified structures (e.g., alkali-treated lignin, Kraft lignin, and lignosulfonates) [38,39,40] as the substrate. Such technical lignins have different structures and characteristics from native lignin because they change during delignification process, associated with delignification and biomass treatment and delignification methods. For example, Kraft lignin contains 1–3% sulfur, used to prepare resins, carbon fibers, and low-molecular-weight compounds. Organosolv lignin is sulfur-free and has many reactive sites, employed as additives to inks, paints, and coatings. Detailed comparison of characteristics of various technical lignin can be found in a recent review by Ekielski and Mishra [41].
In a recent study, a more native-like lignin (poplar sawdust containing 29.4 wt.% lignin) was used for the alkaline aerobic oxidation, as a surrogate substrate for an unmodified, highly reactive, and non-degraded lignin [42]. For this reaction, other than syringaldehyde and vanillin, syringic, p-hydroxybenzoic, and vanillic acids and acetosyringone were identified. During the oxidation of poplar lignin, the resultant syringaldehyde and vanillin were further oxidized to non-aromatic carboxylic acids. Vanillin was much less reactive for the formation of non-aromatic acids than syringaldehyde. High temperatures, high NaOH concentrations in the reactant, and short reaction times favored the production of syringaldehyde and vanillin. The reason why long reaction deteriorates the yield was the aromatic aldehydes degraded rapidly in the presence of oxygen. About 20 wt.% yield of syringaldehyde and vanillin was achieved with the poplar lignin at 175 °C and 0.5 MPa O2 under 2 M NaOH.
The work done by Schutyser et al. also investigated the effect of Cu-based catalysts (CuSO4 or LaMn0.8Cu0.2O3) on alkaline aerobic oxidation of the poplar lignin [42]. These catalysts did not enhance the maximum aromatic aldehyde yield; however, they made the high yield could be obtained at a wider range of reaction conditions. The findings were somewhat contradictory to those of other studies that used modified lignins. This may be because the native-like lignin is reactive enough without catalyst compared to modified ones. The roles and mechanisms of the catalyst in the oxidation of the lignin contained in native biomass could not be explained, remaining as future studies.
Impurities contained in lignin feedstocks (e.g., inorganics and carbohydrates) may hinder the isolation of vanillin and syringaldehyde. Therefore, such impurities need to be removed from lignin (even technical lignin) prior to its oxidation in order to make uniformly fractionated lignin. The use of uniformly fractionated lignin would be beneficial to enhance the yield of vanillin and syringaldehyde. Various approaches to effectively isolate and recover vanillin and syringaldehyde from the reaction stream are found in the studies done by several groups [24,43,44].
Although many studies on the aromatic monomer production from lignin have carried out, there has been no study into economic feasibility of the aldehyde production from lignin yet. A recent paper, however, has reported technoeconomic feasibility of a lignin-derived aromatic compound (e.g., catechol) [45]. The total cost investment of a plant which capacity is 2544 kg of feedstock per day was estimated to be approximately 4.9 million USD. The price of catechol production from lignin was calculated as 1100 USD per ton of catechol (a valorization ratio of 3.02). The estimation indicated that the lignin-derived catechol can be competitive in the market, while it was highly associated with assumptions on price of raw materials and sell price of products. A similar situation should be applied to a large-scale production of lignin-derived aromatic aldehydes.
Table
Table 1. Alkaline aerobic oxidation of different lignin feedstocks.
Table 1. Alkaline aerobic oxidation of different lignin feedstocks.
EntryLignin TypeProductReactionCatalystReaction ConditionsYieldRef.
1Swollen residual enzyme ligninVanillin, SyringaldehydeAlkaline nitrobenzene oxidation-170 °C; 3 hVanillin: 13.39%
Syringaldehyde: 14.19%		Wang et al. [46]
2Double enzymatic ligninVanillin, SyringaldehydeAlkaline nitrobenzene oxidation-170 °C; 3 hVanillin: 9.17%
Syringaldehyde: 15.99%		Wang et al. [46]
3Kraft ligninVanillin, SyringaldehydeAlkaline nitrobenzene oxidation-170 °C; 3 hVanillin: 2.51%
Syringaldehyde: 2.92%		Wang et al. [46]
4Alkali ligninVanillin, SyringaldehydeAlkaline nitrobenzene oxidation-170 °C; 3 hVanillin: 6.52%
Syringaldehyde: 4.16%		Wang et al. [46]
5Kraft ligninVanillinOxidation-120–125 °C; 10 bar; 130 min3.5–7.6%Araújo et al. [27]
6Oil palm empty fruit bunches ligninVanillinNitrobenzene oxidation-165 °C; 3 h1.6%Mohamad Ibrahim et al. [47]
7LignosulfonatesVanillinOxidation 185 °C; 11 atm; 85 min7.2%Bjørsvik and Minisci [31]
8Kraft ligninVanillinChemical oxidation-133 °C; 2.8 bar O2; 35 min10.8%Fargues et al. [25]
9Pine kraft ligninVanillinOxidation-120 °C; 5.5 bar N2, 9.3 bar O2; 60 min10%Mathias and Rodrigues [34]
10Pine wood ligninVanillinOxidation-160 °C; 0.9 MPa O2; 20 min23.1%Taraban’ko et al. [48]
11Poplar ligninVanillin, SyringaldehydeAlkaline aerobic lignin oxidation 175 °C; 5 bar O2, 15 bar He; 10 minVanillin: 7%
Syringaldehyde: 13%		Schutyser et al. [42]
12Eucalyptus globulus dioxane ligninVanillin, SyringaldehydeNitrobenzene oxidation-170 °C; 4 hVanillin: 5.66%
Syringaldehyde: 33.2%		Rodrigues Pinto et al. [28]
13LignosulfonatesVanillin, SyringaldehydeOxidationCuSO4150 °C; 10 bar O2; 20 min; CuSO4 loading of 20%Vanillin: 4.5% Syringaldehyde: 16.1%Santos et al. [32]
14Pine ligninVanillin, SyringaldehydeOxygen delignification-100 °C; 0.7 MPa O2; 60 minVanillin: 8.8%
Syringaldehyde: 0.72%		Wong et al. [49]
15Eucalyptus pulp ligninVanillin, SyringaldehydeOxygen delignification-100 °C; 0.7 MPa O2; 60 minVanillin: 4.62%
Syringaldehyde: 7.85%		Wong et al. [49]
16Cornstalk ligninSyringaldehydeCatalytic oxidationLaFe0.8Cu0.2O3120 °C; 5 bar O2; 30 min; LaFe0.8Cu0.2O3 loading of 5%11.5%Zhang et al. [50]
17Softwood ligninVanillinAlkaline wet oxidation-140 °C; 10 bar O2; 280 min3%Gomes and Rodrigues [51]
18Dealkali ligninSyringaldehydeCatalytic oxidationLaFe0.2Cu0.8O3160 °C; 0.8 MPa O2; 2.5 h; LaFe0.8Cu0.2O3 loading of 5%10%Li et al. [52]
19Kraft ligninVanillinAlkaline wet oxidationCuMn (1:3)150 °C; atmospheric pressure; 60 min; CuMn loading of 0.2%6.7%Jeon et al. [53]
20Native softwood ligninVanillinAerobic oxidation-120 °C; 72 h21%Maeda et al. [54]
21Kraft ligninVanillinAlkaline wet oxidation-140 °C; 10 bar O2; 2 h4.3%Gomes and Rodrigues [55]
22Lignin from
Kraft cooking liquor		VanillinAlkaline nitrobenzene oxidation-170 °C; 3 h,3.9%Gitaari et al. [56]
23Kraft ligninVanillinOxidation-160 °C; 1 MPa O2; 1 h 21.1%Zhu et al. [57]
24Kraft ligninVanillinCatalytic oxidationCuSO4140 °C; 1 h; CuSO4 loading of 10%10.9%Zhang et al. [58]
25Organosolv ligninVanillin, SyringaldehydeElectro-oxidation-Room temperature; 1 h17.5%Yan et al. [59]
26Kraft ligninVanillinOxidative depolymerization-180–220 °C; 1–2 atm O2; 1–2 h1.8–5.2%Liu et al. [60]
27Eucalyptus ligninVanillin, SyringaldehydeAlkaline nitrobenzene oxidation-170 °C; 4 hVanillin: 7.3%
Syringaldehyde: 29.3% 		Ninomiya et al. [61]

3. Production of Polymers from the Lignin-Derived Aromatic Aldehydes

3.1. Production of Vanillin- and Syringaldehyde-Derived Polymers

Lignin can be directly employed to produce various polymers such as polyesters, polyurethanes, and resins [62,63]. The polymers are synthesized directly from lignin via functionalization of hydroxyl groups in lignin structure, or lignin is utilized as blends, copolymers, and composites [64,65]. However, the direct use of lignin for the polymer production has several limitations. For instance, properties of the resultant polymers are highly dependent upon the composition and structure of lignin [66]; therefore, it is challenging to control the properties. In addition, lignin often comprises composites or blends as in minor amounts, and their major portions still originate from petroleum. Compared to lignin itself, lignin-derived monomers such as syringaldehyde and vanillin (discussed in Section 2) have relatively well-defined aromatic structure [65]. This aromatic structure gives important polymer properties like hydrophobicity, rigidity, and resistance to fire. In this section, it will be given an overview of methods employed to make different polymers from the lignin-derived syringaldehyde and vanillin. Figure 2 depicts various polymers that can originate from vanillin or syringaldehyde.
Among a wide range of aromatic monomers can be derived from lignin [67], only vanillin production is currently industrialized, which makes vanillin a particularly attractive monomer for polymer synthesis [63,68]. In earlier applications, vanillin is commonly functionalized to make epoxy resins [69,70,71] by adding a second alcohol [72] and used to make polymeric composite materials [73,74] and resins [75,76,77]. More recently, divanillin is used as a polymer precursor. Divanillin is readily made via enzymatic oxidative dimerization of vanillin on horseradish peroxidase (Armoracia rusticana) [78]. Alternatively, it can be produced oxidative coupling by using laccase [79,80,81], iron(III) chloride [82], and persulfate salts [83,84,85]. For instance, Fang et al. has very recently showed that sodium persulfate (Na2S2O8) is an effective persulfate salt for the synthesis of divanillin due to its high water solubility and inexpensiveness [85]. It could also be electrochemically synthesized [86]. No structural space and short segments in divanillin lead to minimizing rotational motion of its backbone, resulting in dynamic performance of polymeric networks [81,87].
Divanillin has been applied to the synthesis of various polymers including polyvanillin [83,86], Schiff base polymers [88], epoxy thermosets [81,89,90], and lignin oligomers [91]. For example, reaction between divanillin and alkyl diamines in the presence of ethanol followed by reflux resulted in Schiff base polymers having the degree of polymerization ranging from 25 to 32 [88]. Divanillin could also be transformed to α,ω-dienes that were further converted into a conjugated polymer through acyclic diene metathesis [92]. Divanillin was employed as a chain extender to synthesize polyurethanes with a modification with ethanolamine [93]. Divanillin was able to electrochemically polymerized to polyvanillin considered a functionalized renewable polymer [86].
Bisphenols are precursors of a wide variety of polymers including polyesters [79], polycyanurates [72], polycarbonates [72], and epoxy resins [85,94] that are made through simple modifications of the structure of bisphenols. Two strategies have been available to make bisphenols from vanillin. First one involves coupling reactions between aromatic rings of two phenolic compounds through electrophilic condensation [95] or enzymatic dimerization [79]. Second one is to functionalize side chain of the phenolic species, involving coupling of two phenolics via a cross-linker [94] and the generation of stilbenes [72]. Song and co-workers enzymatically co-polymerized syringaldehyde with petro-derived bisphenol A using a peroxidase (Coprinus cinereus) [96].
Polymers synthesized by modifying side chain of vanillin or syringaldehyde have also been reported. Rostagno et al. prepared different polyvinyl aromatic acetals by the condensation of poly(vinyl alcohol) and lignin-derived aromatic aldehydes such as syringaldehyde and vanillin [97]. Polymeric vanillin prodrug-based nanoparticles were synthesized by Kwon et al. [98], which are potentially applied to drug delivery systems and antioxidant therapeutics. Liu et al. derived acrylamides from vanillin via a three-step process which could be polymerized through free radical polymerization [99]. The free radical polymerization could also be used to prepare acrylate polymers from syringaldehyde and vanillin [100].
There have been efforts to expand the application of renewable polymers derived from vanillin and syringaldehyde. For instance, Kakuchi and co-workers have recently exploited the Kabachnik–Fields reaction as a method to post-modify vanillin or syringaldehyde-derived polymer, considering that aldehydes are important reactants in multi-component reactions [101]. The Kabachnik–Fields multi-component reaction between phosphites, amines, and polymers derived from vanillin or syringaldehyde completely changed aldehyde functionalities of the polymers to α-amino phosphonate functionalities.
An interesting use of renewable lignin-derived monomer was reported by Zhang et al. They synthesized polymeric porous microspheres from vanillin [102]. Vanillin first reacted with methacryloyl chloride, which made vanillin methacrylate. Suspension polymerization of the vanillin-derived monomer under aqueous phase resulted in microspheres with a >90 wt.% yield. The microspheres had surface porosity by N2-bubbling and optimizing the co-solvent ratio. When the aldehyde functionalities of the microspheres reacted with glycine, the microspheres were chelated by Schiff base. The chelating microspheres showed a high performance of Cu2+ (as a heavy metal surrogate) adsorption (135 mg g−1). Later on, the same researcher synthesized similar magnetic microspheres composed of polymethacrylate/Fe3O4 nanoparticles [103]. The magnetic moiety allowed an easy separation of the material from liquid media after its use. The microspheres were effective at adsorbing p-anisidine, proving its suitability for enzyme immobilization.

3.2. Properties of Vanillin- and Syringaldehyde-Derived Polymers

Thermoset polymers are used in many applications including coatings, packaging, adhesives, composites, and electronics because of their high strength, high, modulus, and good resistance to heat and chemicals [104]. The properties of thermosets can readily be varied, dependent upon molecular weight, nature of the polymers, and adjustable cross-linking density [105]. Of various classes of thermosets, epoxy resins represent approximately 70% of thermoset market owing to their superior mechanical and adhesive properties and high thermal chemical resistance [106].
The lignin-derived vanillin and syringaldehyde (as discussed in Section 2) can be used to make epoxy thermosets. For example, Zhao and Abu-Omar made triphenylmethane-type polyphenols from syringaldehyde and vanillin [107]. The polyphenols were then reacted with or without linoleic acid (as a plasticizer), followed by epoxidation and curing to obtain a final form of the resin. The use of linoleic acid decreased glass transition temperature from 167 to 82 °C and storage modulus from 12.3 to 3.6 GPa (entry 1 in Table 2).
Zhu and co-workers synthesized vanillin-based epoxy resins having flame retardant properties attributed to phosphorus functionalized by using p-phenylenediamine or 4,4-diaminodiphenylmethane as coupling agent [94]. The procedure led to epoxy resins with thermal and mechanical properties that are comparable to commercial diglycidyl ether of bisphenol A (DGEBA) (entry 2 in Table 2).
Thermoplastic polymers are applied to manufacturing packaging, fibers, furniture, insulators, containers, medical equipment, automotive parts, et cetera. In addition to epoxy thermosets, thermoplastic polymers can be derived from vanillin and syringaldehyde. For instance, different methacrylate polymers with high glass-transition temperatures were derived from vanillin and syringaldehyde. Acrylate- and methacrylate-type monomers were first made, including vanillin acrylate, vanillin methacrylate, syringaldehyde acrylate, and syringaldehyde methacrylate [100]. Free radical polymerization of such monomers yielded their corresponding polymers. The polymers (95–180 °C) had a lot higher glass transition temperature than poly (methyl methacrylate) (PMMA), polystyrene (PS), and polylactic acid (PLA) (48–110 °C) (entry 4 in Table 2). They also had higher initial degradation temperature ranging from 300 to 320 °C than PMMA (280 °C) and PLA (296 °C). Kim group used a dimerized vanillin to partially replace traditionally used chain extender (e.g., 1,4-butanediol) to make polyurethanes [93]. The resultant polymeric materials that containing divanillin-ethanol amine conjugate had enhanced Young’s modulus (8.0–9.7 MPa) and strain (644.8–770.9%) than those of typical polyurethane (7.5 MPa and 522.6%, respectively) (entry 9 in Table 2).
Kayser et al. reported a cross-conjugated pyrrole-based fluorescent polymer comprising biomass-derived monomers such as vanillin and furan-based acid chlorides for the first time [108]. Multi-component polymerization substituted by catechyls and mediated by phosphonites was used to make the cross-conjugated polymer using light alkenes (or alkynes) and diacid chlorides. Investigation into the polymer’s optical properties (e.g., fluorescence and UV-vis absorbance) proved that the polymer is blue-emitting, and the emission can be modulated by modifying its structure. The authors of this study stated that the polymer is potentially applied to produce polymer-based light emitting diode. Properties of more vanillin- and syringaldehyde-derived polymers are also available in Table 2.
Table
Table 2. Thermomechanical properties of vanillin- and syringaldehyde-derived polymers.
Table 2. Thermomechanical properties of vanillin- and syringaldehyde-derived polymers.
EntryMonomersPolymerization MethodFinal PolymerGlass Transition Temperature (°C)Degradation Temperature (°C)Other PropertiesRef.
1Vanillin, syringaldehydeEpoxidation; curing at 80 °C for 8 hEpoxy resin82–167 aT5% = 220–269 b-Zhao et al. [107]
2VanillinEpoxidation; curing at 160 °C for 2 hEpoxy resin166–214 cT5% = 286–356 d-Wang et al. [94]
3Vanillin methacrylateSuspension polymerization; curing at 65 °C for 6 hPolyvanillin methacrylate102 cDegradation T range = 250–480 b-Zhang et al. [102]
4Vanillin, syringaldehydeFree radical polymerization(Meth)acrylate-type polymers95–180 cTmax = 340–360 bMn = 7600–14,600 g mol−1; Đ = 1.89–4.07Zhou et al. [100]
5VanillinElectrochemical reductive polymerizationPolyvanillin-T50% = 440 dMn = 9850–11,784 g mol−1; Đ = 1.42–1.58Amarasekara et al. [86]
6VanillinReversible addition-fragmentation chain-transfer (RAFT) polymerizationMethacrylate-type polymers111–139Tmax = 281–327Mn = 15,000–41,000 g mol−1; Đ = 1.12–1.39Holmberg et al. [109]
7Syringyl methacrylateRAFT polymerizationPoly(syringyl methacrylate)114–205 eInitial degradation T = 256–303 dMn = 11000–38,000 g mol−1; Đ = 1.32–1.74Holmberg et al. [110]
8Vanillin-derived bis-benzoxazine monomerRing opening polymerizationPoly(bisbenzoxazine)202–255 eDegradation T range = 220–450 b-Sini et al. [111]
9Vanillin-Divanillin-ethanol amine conjugate-based
polyurethane		−68.1 to −67.2 cT5% = 329.6–341.5 b-Gang et al. [93]
10Vanillin, syringaldehyde, etc.-Polyvinyl acetals114–157T95% = 185–308 bMn = 22,300–46,000 g mol−1Rostagno et al. [97]
11Vanillin-Poly (ether benzoxazole)->400 b-Sun et al. [112]
12Vanillin-based monomersPhosphonite-mediated
multicomponent polymerization		Fluorescent polymers--Mn = 3000–12,700 g mol−1; Đ = 1.8–2.3Kayser et al. [108]
13Vanillyl alcohol-Polyurethane59T5% = 178 bMw = 32,000 g mol−1 Tachibana and Abe [113]
14Vanillin-Polyurethane (PU-3)80.4 cT5% = 229 bMn = 4000 g mol−1 Zhao et al. [114]
15Vanillin-Cured epoxy resins-T5% = 394 b-Shibata and Ohkita [115]
16VanillinPhthalonitrile functionalizationPhthalonitrile resins>500 cT5% = 477–482 b-Han et al. [116]
17HydrovanilloinElectrochemical dimerizationHydrovanilloin—Diglycidyl Ether Phenoxy Resin135T = 255 d-Amarasekara et al. [117]
18Vanillin methacrylateFree radical solution homo-polymerizationVanillin-derived polymer (PVMA)--Mn = 17,900 g mol−1Zhao et al. [118]
a By dynamic mechanical analysis; b By thermogravimetric analysis (TGA) in N2; c By differential scanning calorimetry (DSC) in N2; d By TGA in air; e By DSC in air.

4. Summary and Outlook

Lignin is an intriguing aromatic biopolymer. The release of more chemicals derived from lignin can expand available biorefinery feedstocks, thereby making economics of biorefineries and pulp and paper industries profitable. In this regard, this review gives an overview of processes that enable to deliver bio-based polymers from pre-isolated lignin or lignocellulose in good selectivities. As shown in this review, the applications of lignin to the manufacture of bio-based polymers demonstrate why lignin is regarded as a key renewable source in biorefineries. However, there are still challenges that need to be solved to be capable of the full implementation of lignin as renewable feedstock for bio-based polymers.
There are a large number of strategies to transform lignin into aromatic aldehydes such as syringaldehyde and vanillin. Many studies have recognized that re-condensation reactions occurring during processing lignocellulosic biomass and lignin conversion processes have pronounced effects on the product yields. Efforts to suppress the undesired reactions have been made. For instance, the introduction of formaldehyde to isolating lignin from lignocellulosic biomass achieved the yields at a near theoretical maximum [119]. Stabilization of reactive intermediate species during acidolysis of organosolv lignin was also reported [120,121,122]. Reductive catalytic fractionation led to high selectivities toward defined target products rather than obtaining a complex mixture of products [123].
The aerobic oxidation of lignin reported so far needs for high amounts of oxygen and alkali medium. However, most studies have still focused on increasing yields of target products, although reducing the oxygen and alkali consumption is clearly attention-worthy issue [124]. More efforts should be made to figure out how to lower the consumption of oxygen and alkali during the aromatic aldehyde production.
Most studies into the production of aromatic aldehydes from lignin that are currently available have laid emphasis on solving fundamental challenges of selective β-O-4 bond cleavage in lignin. However, cleavage of other linkages in lignin needs to be more actively investigated to fully valorize all lignin components. Stable and reusable catalysts that are tolerant to impurities contained in lignin should be developed [125]. Upscaling of experiments on converting lignin into the monomers is also required as an effort to make the lignin valorization process more economically viable.
For the conversion of lignin into aromatic aldehyde monomers, it is difficult to make a direct comparison of the conversion processes because characteristics and properties of lignin substances (e.g., purity, solubility, molecular weight, and β-O-4 content) are different, dependent upon the methods of lignin isolation and processing developed by different research groups. Thus, standardization of reporting performance of the lignin conversion methods is required. Regarding the standardization, the lack of standard lignin samples that have reproducible quality is a serious challenge. It is also necessary to standardize existing techniques for analysis both of the structure of lignin and lignocellulose and of lignin-derived complicated product mixtures.
Considerable advancements have come with polymers made from lignin-derived aromatic aldehydes. Many research groups have used pure and well-defined lignin substrates available from commercial sources to synthesize bio-based polymers, particularly thermoplastics and thermosets with comparable properties to conventional materials. However, there is still a discrepancy between chemical compounds frequently obtained from depolymerization of lignin and monomers most frequently used for the production of bio-based polymers. Novel methods to make the actual monomers with high yields are needed, which can open up possibilities of synthesizing emerging bio-based polymers having desired properties.
Catalytic conversions of lignin typically result in mixtures of different aromatic compounds that are directly employed to synthesize bio-based polymers. This can allow to avoid additional purification or separation steps, if reproducibility associated with the kind of lignin feedstocks and the composition of the aromatic mixtures is clarified. Moreover, the lignin-derived bio-based polymers are not degradable in nature; hence, their biodegradability and toxicity in the environment need to be further investigated.
In the past, the use of lignin as a starting material for the production of other chemicals was skeptical because the breakage of recalcitrant structure of lignin was a daunting task. Today, considerable advancements in research into biorefinery and catalysis make it possible the production of lignin-derived platform chemicals in acceptable yields. However, the full implementation of lignin as renewable feedstock for bio-based polymers still requires active collaborations across multiple disciplines and a constructive dialogue between people working in academia and industry. Constant efforts to develop lignin valorization processes will be essential for further innovation in biorefinery technologies.

Author Contributions

Conceptualization, J.L.; writing—original draft preparation, N.L., Y.T.K. and J.L.; writing—review and editing, N.L., Y.T.K. and J.L.; visualization, N.L. and Y.T.K.; supervision, J.L. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (Ministry of Science and ICT) (No. NRF-2020R1C1C1003225). This work was also supported by the KRICT project (SI2112-10) of the Korea Research Institute of Chemical Technology.

Institutional Review Board Statement

Not Applicable.

Informed Consent Statement

Not Applicable.

Data Availability Statement

Not Applicable.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. De Bhowmick, G.; Sarmah, A.K.; Sen, R. Lignocellulosic biorefinery as a model for sustainable development of biofuels and value added products. Bioresour. Technol. 2018, 247, 1144–1154. [Google Scholar] [CrossRef] [PubMed]
  2. Kwon, E.E.; Lee, T.; Ok, Y.S.; Tsang, D.C.W.; Park, C.; Lee, J. Effects of calcium carbonate on pyrolysis of sewage sludge. Energy 2018, 153, 726–731. [Google Scholar] [CrossRef]
  3. Jung, J.-M.; Oh, J.-I.; Baek, K.; Lee, J.; Kwon, E.E. Biodiesel production from waste cooking oil using biochar derived from chicken manure as a porous media and catalyst. Energy Convers. Manag. 2018, 165, 628–633. [Google Scholar] [CrossRef]
  4. Kim, S.; Kwon, E.E.; Kim, Y.T.; Jung, S.; Kim, H.J.; Huber, G.W.; Lee, J. Recent advances in hydrodeoxygenation of biomass-derived oxygenates over heterogeneous catalysts. Green Chem. 2019, 21, 3715–3743. [Google Scholar] [CrossRef]
  5. Park, C.; Lee, J. Recent achievements in CO2-assisted and CO2-catalyzed biomass conversion reactions. Green Chem. 2020, 22, 2628–2642. [Google Scholar] [CrossRef]
  6. Cagnon, B.; Py, X.; Guillot, A.; Stoeckli, F.; Chambat, G. Contributions of hemicellulose, cellulose and lignin to the mass and the porous properties of chars and steam activated carbons from various lignocellulosic precursors. Bioresour. Technol. 2009, 100, 292–298. [Google Scholar] [CrossRef] [Green Version]
  7. Schutyser, W.; Renders, T.; Van den Bosch, S.; Koelewijn, S.F.; Beckham, G.T.; Sels, B.F. Chemicals from lignin: An interplay of lignocellulose fractionation, depolymerisation, and upgrading. Chem. Soc. Rev. 2018, 47, 852–908. [Google Scholar] [CrossRef]
  8. Sun, Z.; Fridrich, B.; de Santi, A.; Elangovan, S.; Barta, K. Bright side of lignin depolymerization: Toward new platform chemicals. Chem. Rev. 2018, 118, 614–678. [Google Scholar] [CrossRef] [Green Version]
  9. Rinaldi, R.; Jastrzebski, R.; Clough, M.T.; Ralph, J.; Kennema, M.; Bruijnincx, P.C.A.; Weckhuysen, B.M. Paving the way for lignin valorisation: Recent advances in bioengineering, biorefining and catalysis. Angew. Chem. Int. Ed. 2016, 55, 8164–8215. [Google Scholar] [CrossRef] [Green Version]
  10. Gillet, S.; Aguedo, M.; Petitjean, L.; Morais, A.R.C.; da Costa Lopes, A.M.; Łukasik, R.M.; Anastas, P.T. Lignin transformations for high value applications: Towards targeted modifications using green chemistry. Green Chem. 2017, 19, 4200–4233. [Google Scholar] [CrossRef]
  11. Shuai, L.; Saha, B. Towards high-yield lignin monomer production. Green Chem. 2017, 19, 3752–3758. [Google Scholar] [CrossRef]
  12. Renders, T.; Van den Bosch, S.; Koelewijn, S.F.; Schutyser, W.; Sels, B.F. Lignin-first biomass fractionation: The advent of active stabilisation strategies. Energy Environ. Sci. 2017, 10, 1551–1557. [Google Scholar] [CrossRef]
  13. Gierer, J. Chemistry of delignification. Wood Sci. Technol. 1985, 19, 289–312. [Google Scholar] [CrossRef]
  14. Sturgeon, M.R.; Kim, S.; Lawrence, K.; Paton, R.S.; Chmely, S.C.; Nimlos, M.; Foust, T.D.; Beckham, G.T. A mechanistic investigation of acid-catalyzed cleavage of aryl-ether linkages: Implications for lignin depolymerization in acidic environments. ACS Sustain. Chem. Eng. 2014, 2, 472–485. [Google Scholar] [CrossRef]
  15. Pu, Y.; Hu, F.; Huang, F.; Ragauskas, A.J. Lignin structural alterations in thermochemical pretreatments with limited delignification. Bioenerg. Res. 2015, 8, 992–1003. [Google Scholar] [CrossRef]
  16. Liu, S.; Bai, L.; van Muyden, A.P.; Huang, Z.; Cui, X.; Fei, Z.; Li, X.; Hu, X.; Dyson, P.J. Oxidative cleavage of β-O-4 bonds in lignin model compounds with a single-atom Co catalyst. Green Chem. 2019, 21, 1974–1981. [Google Scholar] [CrossRef]
  17. Lora, J. Industrial commercial lignins: Sources, properties and applications. In Monomers, Polymers and Composites from Renewable Resources; Belgacem, M.N., Gandini, A., Eds.; Elsevier: Amsterdam, The Netherlands, 2008; pp. 225–241. [Google Scholar] [CrossRef]
  18. Ragauskas, A.J.; Beckham, G.T.; Biddy, M.J.; Chandra, R.; Chen, F.; Davis, M.F.; Davison, B.H.; Dixon, R.A.; Gilna, P.; Keller, M.; et al. Lignin valorization: Improving lignin processing in the biorefinery. Science 2014, 344, 1246843. [Google Scholar] [CrossRef]
  19. Davis, R.; Tao, L.; Tan, E.; Biddy, M.; Beckham, G.; Scarlata, C.; Jacobson, J.; Cafferty, K.; Ross, J.; Lukas, J. Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons: Dilute-Acid and Enzymatic Deconstruction of Biomass to Sugars and Biological Conversion of Sugars to Hydrocarbons; Report NREL/TP-5100-60223; National Renewable Energy Laboratory: Golden, CO, USA, 2013.
  20. Zhu, Y.; Romain, C.; Williams, C.K. Sustainable polymers from renewable resources. Nature 2016, 540, 354–362. [Google Scholar] [CrossRef]
  21. Delidovich, I.; Hausoul, P.J.C.; Deng, L.; Pfützenreuter, R.; Rose, M.; Palkovits, R. Alternative monomers based on lignocellulose and their use for polymer production. Chem. Rev. 2016, 116, 1540–1599. [Google Scholar] [CrossRef]
  22. Cheng, C.; Wang, J.; Shen, D.; Xue, J.; Guan, S.; Gu, S.; Luo, K.H. Catalytic oxidation of lignin in solvent systems for production of renewable chemicals: A review. Polymers 2017, 9, 240. [Google Scholar] [CrossRef] [Green Version]
  23. Rodrigues Pinto, P.C.; Borges da Silva, E.A.; Rodrigues, A.E. Lignin as source of fine chemicals: Vanillin and syringaldehyde. In Biomass Conversion: The Interface of Biotechnology, Chemistry and Materials Science; Baskar, C., Baskar, S., Dhillon, R.S., Eds.; Springer: Berlin/Heidelberg, Germany, 2012; pp. 381–420. [Google Scholar] [CrossRef]
  24. Fache, M.; Boutevin, B.; Caillol, S. Vanillin production from lignin and its use as a renewable chemical. ACS Sustain. Chem. Eng. 2016, 4, 35–46. [Google Scholar] [CrossRef]
  25. Fargues, C.; Mathias, Á.; Rodrigues, A. Kinetics of vanillin production from Kraft lignin oxidation. Ind. Eng. Chem. Res. 1996, 35, 28–36. [Google Scholar] [CrossRef]
  26. Villar, J.C.; Caperos, A.; García-Ochoa, F. Oxidation of hardwood Kraft-lignin to phenolic derivatives with oxygen as oxidant. Wood Sci. Technol. 2001, 35, 245–255. [Google Scholar] [CrossRef]
  27. Araújo, J.D.P.; Grande, C.A.; Rodrigues, A.E. Vanillin production from lignin oxidation in a batch reactor. Chem. Eng. Res. Des. 2010, 88, 1024–1032. [Google Scholar] [CrossRef]
  28. Rodrigues Pinto, P.C.; Borges da Silva, E.A.; Rodrigues, A.E. Insights into oxidative conversion of lignin to high-added-value phenolic aldehydes. Ind. Eng. Chem. Res. 2011, 50, 741–748. [Google Scholar] [CrossRef]
  29. Pinto, P.C.R.; Costa, C.E.; Rodrigues, A.E. Oxidation of lignin from Eucalyptus globulus pulping liquors to produce syringaldehyde and vanillin. Ind. Eng. Chem. Res. 2013, 52, 4421–4428. [Google Scholar] [CrossRef]
  30. Tarabanko, V.E.; Fomova, N.A.; Kuznetsov, B.N.; Ivanchenko, N.M.; Kudryashev, A.V. On the mechanism of vanillin formation in the catalytic oxidation of lignin with oxygen. React. Kinet. Catal. Lett. 1995, 55, 161–170. [Google Scholar] [CrossRef]
  31. Bjørsvik, H.-R.; Minisci, F. Fine chemicals from lignosulfonates. 1. Synthesis of vanillin by oxidation of lignosulfonates. Org. Process Res. Dev. 1999, 3, 330–340. [Google Scholar] [CrossRef]
  32. Santos, S.G.; Marques, A.P.; Lima, D.L.D.; Evtuguin, D.V.; Esteves, V.I. Kinetics of Eucalypt lignosulfonate oxidation to aromatic aldehydes by oxygen in alkaline medium. Ind. Eng. Chem. Res. 2011, 50, 291–298. [Google Scholar] [CrossRef] [Green Version]
  33. Pacek, A.W.; Ding, P.; Garrett, M.; Sheldrake, G.; Nienow, A.W. Catalytic conversion of sodium lignosulfonate to vanillin: Engineering aspects. Part 1. Effects of processing conditions on vanillin yield and selectivity. Ind. Eng. Chem. Res. 2013, 52, 8361–8372. [Google Scholar] [CrossRef]
  34. Mathias, A.L.; Rodrigues, A.E. Production of vanillin by oxidation of pine Kraft lignins with oxygen. Holzforschung 1995, 49, 273–278. [Google Scholar] [CrossRef]
  35. Tarabanko, V.E.; Petukhov, D.V. Study of mechanism and improvement of the process of oxidative cleavage of lignins into the aromatic aldehydes. Chem. Sustain. Dev. 2003, 11, 655–667. [Google Scholar]
  36. Tarabanko, V.E.; Petukhov, D.V.; Selyutin, G.E. New mechanism for the catalytic oxidation of lignin to vanillin. Kinet. Catal. 2004, 45, 569–577. [Google Scholar] [CrossRef]
  37. Hosoya, T.; Yamamoto, K.; Miyafuji, H.; Yamada, T. Selective production of bio-based aromatics by aerobic oxidation of native soft wood lignin in tetrabutylammonium hydroxide. RSC Adv. 2020, 10, 19199–19210. [Google Scholar] [CrossRef]
  38. Wu, G.; Heitz, M. Catalytic mechanism of Cu2+ and Fe3+ in alkaline O2 oxidation of lignin. J. Wood Chem. Technol. 1995, 15, 189–202. [Google Scholar] [CrossRef]
  39. Araújo, J.D.P.; Grande, C.A.; Rodrigues, A.E. Structured packed bubble column reactor for continuous production of vanillin from Kraft lignin oxidation. Catal. Today 2009, 147, S330–S335. [Google Scholar] [CrossRef]
  40. Constant, S.; Wienk, H.L.J.; Frissen, A.E.; Peinder, P.d.; Boelens, R.; Van Es, D.S.; Grisel, R.J.H.; Weckhuysen, B.M.; Huijgen, W.J.J.; Gosselink, R.J.A.; et al. New insights into the structure and composition of technical lignins: A comparative characterisation study. Green Chem. 2016, 18, 2651–2665. [Google Scholar] [CrossRef] [Green Version]
  41. Ekielski, A.; Mishra, P.K. Lignin for bioeconomy: The present and future role of technical lignin. Int. J. Mol. Sci. 2021, 22, 63. [Google Scholar] [CrossRef]
  42. Schutyser, W.; Kruger, J.S.; Robinson, A.M.; Katahira, R.; Brandner, D.G.; Cleveland, N.S.; Mittal, A.; Peterson, D.J.; Meilan, R.; Román-Leshkov, Y.; et al. Revisiting alkaline aerobic lignin oxidation. Green Chem. 2018, 20, 3828–3844. [Google Scholar] [CrossRef]
  43. Silva, E.A.B.D.; Zabkova, M.; Araújo, J.D.; Cateto, C.A.; Barreiro, M.F.; Belgacem, M.N.; Rodrigues, A.E. An integrated process to produce vanillin and lignin-based polyurethanes from Kraft lignin. Chem. Eng. Res. Des. 2009, 87, 1276–1292. [Google Scholar] [CrossRef]
  44. Mota, M.I.F.; Rodrigues Pinto, P.C.; Loureiro, J.M.; Rodrigues, A.E. Recovery of vanillin and syringaldehyde from lignin oxidation: A review of separation and purification processes. Sep. Purif. Rev. 2016, 45, 227–259. [Google Scholar] [CrossRef]
  45. Mabrouk, A.; Erdocia, X.; Alriols, M.G.; Labidi, J. Economic analysis of a biorefinery process for catechol production from lignin. J. Clean. Prod. 2018, 198, 133–142. [Google Scholar] [CrossRef]
  46. Wang, Y.; Sun, S.; Li, F.; Cao, X.; Sun, R. Production of vanillin from lignin: The relationship between β-O-4 linkages and vanillin yield. Ind. Crops Prod. 2018, 116, 116–121. [Google Scholar] [CrossRef]
  47. Mohamad Ibrahim, M.N.; Nadiah, M.Y.N.; Norliyana, M.S.; Sipaut, C.S.; Shuib, S. Separation of vanillin from oil palm empty fruit bunch lignin. Clean (Weinh.) 2008, 36, 287–291. [Google Scholar] [CrossRef]
  48. Taraban’ko, V.E.; Koropatchinskaya, N.V.; Kudryashev, A.V.; Kuznetsov, B.N. Influence of lignin origin on the efficiency of the catalytic oxidation of lignin into vanillin and syringaldehyde. Russ. Chem. Bull. 1995, 44, 367–371. [Google Scholar] [CrossRef]
  49. Wong, Z.; Chen, K.; Li, J. Formation of vanillin and syringaldehyde in an oxygen delignification process. Bioresources 2010, 5, 1509–1516. [Google Scholar]
  50. Zhang, J.; Deng, H.; Lin, L. Wet aerobic oxidation of lignin into aromatic aldehydes catalysed by a perovskite-type oxide: LaFe1-xCuxO3 (x=0, 0.1, 0.2). Molecules 2009, 14, 2747–2757. [Google Scholar] [CrossRef]
  51. Gomes, E.D.; Rodrigues, A.E. Lignin biorefinery: Separation of vanillin, vanillic acid and acetovanillone by adsorption. Sep. Purif. Technol. 2019, 216, 92–101. [Google Scholar] [CrossRef]
  52. Li, Y.-X.; Zhu, J.-P.; Zhang, Z.-J.; Qu, Y.-S. Preparation of syringaldehyde from lignin by catalytic oxidation of perovskite-type oxides. ACS Omega 2020, 5, 2107–2113. [Google Scholar] [CrossRef]
  53. Jeon, W.; Choi, I.-H.; Park, J.-Y.; Lee, J.-S.; Hwang, K.-R. Alkaline wet oxidation of lignin over Cu-Mn mixed oxide catalysts for production of vanillin. Catal. Today 2020, 352, 95–103. [Google Scholar] [CrossRef]
  54. Maeda, M.; Hosoya, T.; Yoshioka, K.; Miyafuji, H.; Ohno, H.; Yamada, T. Vanillin production from native softwood lignin in the presence of tetrabutylammonium ion. J. Wood Sci. 2018, 64, 810–815. [Google Scholar] [CrossRef] [Green Version]
  55. Gomes, E.D.; Rodrigues, A.E. Recovery of vanillin from kraft lignin depolymerization with water as desorption eluent. Sep. Purif. Technol. 2020, 239, 116551. [Google Scholar] [CrossRef]
  56. Gitaari, N.; Benard, K.; Gichuki, J.; Kareru, P. Synthesis of vanillin from lignin. Chem. Sci. Int. J. 2019, 27, 1–5. [Google Scholar] [CrossRef]
  57. Zhu, Y.; Liao, Y.; Lv, W.; Liu, J.; Song, X.; Chen, L.; Wang, C.; Sels, B.F.; Ma, L. Complementing vanillin and cellulose production by oxidation of lignocellulose with stirring control. ACS Sustain. Chem. Eng. 2020, 8, 2361–2374. [Google Scholar] [CrossRef]
  58. Zhang, R.; Maltari, R.; Guo, M.; Kontro, J.; Eronen, A.; Repo, T. Facile synthesis of vanillin from fractionated Kraft lignin. Ind. Crops Prod. 2020, 145, 112095. [Google Scholar] [CrossRef]
  59. Yan, K.; Zhang, Y.; Tu, M.; Sun, Y. Electrocatalytic valorization of organosolv lignin utilizing a nickel-based electrocatalyst. Energy Fuels 2020, 34, 12703–12709. [Google Scholar] [CrossRef]
  60. Liu, S.; Das, L.; Blauch, D.N.; Veronee, C.; Dou, C.; Gladden, J.; Sun, N.; Socha, A.M. Statistical design of experiments for production and purification of vanillin and aminophenols from commercial lignin. Green Chem. 2020, 22, 3917–3926. [Google Scholar] [CrossRef]
  61. Ninomiya, K.; Ochiai, K.; Eguchi, M.; Kuroda, K.; Tsuge, Y.; Ogino, C.; Taima, T.; Takahashi, K. Oxidative depolymerization potential of biorefinery lignin obtained by ionic liquid pretreatment and subsequent enzymatic saccharification of eucalyptus. Ind. Crops Prod. 2018, 111, 457–461. [Google Scholar] [CrossRef]
  62. Westwood, N.J.; Panovic, I.; Lancefield, C.S. Chemical modification of lignin for renewable polymers or chemicals. In Production of Biofuels and Chemicals from Lignin; Fang, Z., Smith, J.R.L., Eds.; Springer: Singapore, 2016; pp. 183–216. [Google Scholar] [CrossRef]
  63. Upton, B.M.; Kasko, A.M. Strategies for the conversion of lignin to high-value polymeric materials: Review and perspective. Chem. Rev. 2016, 116, 2275–2306. [Google Scholar] [CrossRef]
  64. Sen, S.; Patil, S.; Argyropoulos, D.S. Thermal properties of lignin in copolymers, blends, and composites: A review. Green Chem. 2015, 17, 4862–4887. [Google Scholar] [CrossRef]
  65. Faruk, O.; Sain, M. Lignin in Polymer Composites; Elsevier: Amsterdam, The Netherlands, 2016. [Google Scholar]
  66. Llevot, A.; Grau, E.; Carlotti, S.; Grelier, S.; Cramail, H. From lignin-derived aromatic compounds to novel biobased polymers. Macromol. Rapid Commun. 2016, 37, 9–28. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  67. Li, C.; Zhao, X.; Wang, A.; Huber, G.W.; Zhang, T. Catalytic transformation of lignin for the production of chemicals and fuels. Chem. Rev. 2015, 115, 11559–11624. [Google Scholar] [CrossRef] [PubMed]
  68. Fache, M.; Boutevin, B.; Caillol, S. Vanillin, a key-intermediate of biobased polymers. Eur. Polym. J. 2015, 68, 488–502. [Google Scholar] [CrossRef]
  69. Fache, M.; Darroman, E.; Besse, V.; Auvergne, R.; Caillol, S.; Boutevin, B. Vanillin, a promising biobased building-block for monomer synthesis. Green Chem. 2014, 16, 1987–1998. [Google Scholar] [CrossRef]
  70. Fache, M.; Viola, A.; Auvergne, R.; Boutevin, B.; Caillol, S. Biobased epoxy thermosets from vanillin-derived oligomers. Eur. Polym. J. 2015, 68, 526–535. [Google Scholar] [CrossRef]
  71. Fache, M.; Auvergne, R.; Boutevin, B.; Caillol, S. New vanillin-derived diepoxy monomers for the synthesis of biobased thermosets. Eur. Polym. J. 2015, 67, 527–538. [Google Scholar] [CrossRef]
  72. Harvey, B.G.; Guenthner, A.J.; Meylemans, H.A.; Haines, S.R.L.; Lamison, K.R.; Groshens, T.J.; Cambrea, L.R.; Davis, M.C.; Lai, W.W. Renewable thermosetting resins and thermoplastics from vanillin. Green Chem. 2015, 17, 1249–1258. [Google Scholar] [CrossRef]
  73. Stanzione Iii, J.F.; Sadler, J.M.; La Scala, J.J.; Reno, K.H.; Wool, R.P. Vanillin-based resin for use in composite applications. Green Chem. 2012, 14, 2346–2352. [Google Scholar] [CrossRef]
  74. Mirzakhanian, Z.; Faghihi, K.; Geravi, H.A.; Mahdieh, M. Semi-aromatic polyimide/Ag nanocomposite derived from vanillin. J. Appl. Polym. Sci. 2016, 133, 44001. [Google Scholar] [CrossRef]
  75. Chauhan, N.P.S.; Kataria, P.; Chaudhary, J.; Ameta, S.C. Synthesis, Characterization, and Thermal Studies of Terpolymers Derived from Vanillin, Furfural, and Halo-Substituted Acetophenones. Int. J. Polym. Mater. Polym. Biomater. 2012, 61, 57–71. [Google Scholar] [CrossRef]
  76. Chauhan, N.P.S. Preparation and characterization of bio-based terpolymer derived from vanillin oxime, formaldehyde, and p-hydroxyacetophenone. Des. Monomers Polym. 2014, 17, 176–185. [Google Scholar] [CrossRef] [Green Version]
  77. Sini, N.K.; Bijwe, J.; Varma, I.K. Renewable benzoxazine monomer from Vanillin: Synthesis, characterization, and studies on curing behavior. J. Polym. Sci. Part A Polym. Chem. 2014, 52, 7–11. [Google Scholar] [CrossRef]
  78. Nishimura, R.T.; Giammanco, C.H.; Vosburg, D.A. Green, enzymatic syntheses of divanillin and diapocynin for the organic, biochemistry, or advanced general chemistry laboratory. J. Chem. Educ. 2010, 87, 526–527. [Google Scholar] [CrossRef]
  79. Llevot, A.; Grau, E.; Carlotti, S.; Grelier, S.; Cramail, H. Renewable (semi)aromatic polyesters from symmetrical vanillin-based dimers. Polym. Chem. 2015, 6, 6058–6066. [Google Scholar] [CrossRef] [Green Version]
  80. Llevot, A.; Grau, E.; Carlotti, S.; Grelier, S.; Cramail, H. Selective laccase-catalyzed dimerization of phenolic compounds derived from lignin: Towards original symmetrical bio-based (bis) aromatic monomers. J. Mol. Catal. B Enzym. 2016, 125, 34–41. [Google Scholar] [CrossRef] [Green Version]
  81. Savonnet, E.; Grau, E.; Grelier, S.; Defoort, B.; Cramail, H. Divanillin-based epoxy precursors as DGEBA substitutes for biobased epoxy thermosets. ACS Sustain. Chem. Eng. 2018, 6, 11008–11017. [Google Scholar] [CrossRef]
  82. Yamamoto, H.; Hoshino, T.; Uchiyama, T. Convenient preparation and quantification of 5,5′-diferulic acid. Biosci. Biotechnol. Biochem. 1999, 63, 390–394. [Google Scholar] [CrossRef] [Green Version]
  83. Kelly, D.R.; Baker, S.C.; King, D.S.; de Silva, D.S.; Lord, G.; Taylor, J.P. Studies of nitrile oxide cycloadditions, and the phenolic oxidative coupling of vanillin aldoxime by Geobacillus sp. DDS012 from Italian rye grass silage. Org. Biomol. Chem. 2008, 6, 787–796. [Google Scholar] [CrossRef]
  84. Delomenède, M.; Bedos-Belval, F.; Duran, H.; Vindis, C.; Baltas, M.; Nègre-Salvayre, A. Development of novel antiatherogenic biaryls: Design, synthesis, and reactivity. J. Med. Chem. 2008, 51, 3171–3181. [Google Scholar] [CrossRef]
  85. Fang, Z.; Nikafshar, S.; Hegg, E.L.; Nejad, M. Biobased divanillin as a precursor for formulating biobased epoxy resin. ACS Sustain. Chem. Eng. 2020, 8, 9095–9103. [Google Scholar] [CrossRef]
  86. Amarasekara, A.S.; Wiredu, B.; Razzaq, A. Vanillin based polymers: I. An electrochemical route to polyvanillin. Green Chem. 2012, 14, 2395–2397. [Google Scholar] [CrossRef]
  87. Maiorana, A.; Reano, A.F.; Centore, R.; Grimaldi, M.; Balaguer, P.; Allais, F.; Gross, R.A. Structure property relationships of biobased n-alkyl bisferulate epoxy resins. Green Chem. 2016, 18, 4961–4973. [Google Scholar] [CrossRef]
  88. Amarasekara, A.S.; Razzaq, A. Vanillin-based polymers—Part II: Synthesis of Schiff base polymers of divanillin and their chelation with metal ions. ISRN Polym. Sci. 2012, 2012, 532171. [Google Scholar] [CrossRef] [Green Version]
  89. Fache, M.; Boutevin, B.; Caillol, S. Epoxy thermosets from model mixtures of the lignin-to-vanillin process. Green Chem. 2016, 18, 712–725. [Google Scholar] [CrossRef]
  90. Zhao, S.; Abu-Omar, M.M. Recyclable and malleable epoxy thermoset bearing aromatic imine bonds. Macromolecules 2018, 51, 9816–9824. [Google Scholar] [CrossRef]
  91. Forsythe, W.G.; Garrett, M.D.; Hardacre, C.; Nieuwenhuyzen, M.; Sheldrake, G.N. An efficient and flexible synthesis of model lignin oligomers. Green Chem. 2013, 15, 3031–3038. [Google Scholar] [CrossRef]
  92. Llevot, A.; Grau, E.; Carlotti, S.; Grelier, S.; Cramail, H. ADMET polymerization of bio-based biphenyl compounds. Polym. Chem. 2015, 6, 7693–7700. [Google Scholar] [CrossRef] [Green Version]
  93. Gang, H.; Lee, D.; Choi, K.-Y.; Kim, H.-N.; Ryu, H.; Lee, D.-S.; Kim, B.-G. Development of high performance polyurethane elastomers using vanillin-based green polyol chain extender originating from lignocellulosic biomass. ACS Sustain. Chem. Eng. 2017, 5, 4582–4588. [Google Scholar] [CrossRef]
  94. Wang, S.; Ma, S.; Xu, C.; Liu, Y.; Dai, J.; Wang, Z.; Liu, X.; Chen, J.; Shen, X.; Wei, J.; et al. Vanillin-derived high-performance flame retardant epoxy resins: Facile synthesis and properties. Macromolecules 2017, 50, 1892–1901. [Google Scholar] [CrossRef]
  95. Hernandez, E.D.; Bassett, A.W.; Sadler, J.M.; La Scala, J.J.; Stanzione, J.F. Synthesis and characterization of bio-based epoxy resins derived from vanillyl alcohol. ACS Sustain. Chem. Eng. 2016, 4, 4328–4339. [Google Scholar] [CrossRef]
  96. An, E.S.; Cho, D.H.; Choi, J.W.; Kim, Y.H.; Song, B.K. Peroxidase-catalyzed copolymerization of syringaldehyde and bisphenol A. Enzyme Microb. Technol. 2010, 46, 287–291. [Google Scholar] [CrossRef]
  97. Rostagno, M.; Shen, S.; Ghiviriga, I.; Miller, S.A. Sustainable polyvinyl acetals from bioaromatic aldehydes. Polym. Chem. 2017, 8, 5049–5059. [Google Scholar] [CrossRef]
  98. Kwon, J.; Kim, J.; Park, S.; Khang, G.; Kang, P.M.; Lee, D. Inflammation-responsive antioxidant nanoparticles based on a polymeric prodrug of vanillin. Biomacromolecules 2013, 14, 1618–1626. [Google Scholar] [CrossRef] [PubMed]
  99. Liu, H.; Lepoittevin, B.; Roddier, C.; Guerineau, V.; Bech, L.; Herry, J.-M.; Bellon-Fontaine, M.-N.; Roger, P. Facile synthesis and promising antibacterial properties of a new guaiacol-based polymer. Polymer 2011, 52, 1908–1916. [Google Scholar] [CrossRef]
  100. Zhou, J.; Zhang, H.; Deng, J.; Wu, Y. High glass-transition temperature acrylate polymers derived from biomasses, syringaldehyde, and vanillin. Macromol. Chem. Phys. 2016, 217, 2402–2408. [Google Scholar] [CrossRef]
  101. Kakuchi, R.; Yoshida, S.; Sasaki, T.; Kanoh, S.; Maeda, K. Multi-component post-polymerization modification reactions of polymers featuring lignin-model compounds. Polym. Chem. 2018, 9, 2109–2115. [Google Scholar] [CrossRef]
  102. Zhang, H.; Yong, X.; Zhou, J.; Deng, J.; Wu, Y. Biomass vanillin-derived polymeric microspheres containing functional aldehyde groups: Preparation, characterization, and application as adsorbent. ACS Appl. Mater. Interfaces 2016, 8, 2753–2763. [Google Scholar] [CrossRef]
  103. Zhang, H.; Deng, J.; Wu, Y. Biobased magnetic microspheres containing aldehyde groups: Constructed by vanillin-derived polymethacrylate/Fe3O4 and recycled in adsorbing amine. ACS Sustain. Chem. Eng. 2017, 5, 658–666. [Google Scholar] [CrossRef]
  104. Ma, S.; Li, T.; Liu, X.; Zhu, J. Research progress on bio-based thermosetting resins. Polym. Int. 2016, 65, 164–173. [Google Scholar] [CrossRef]
  105. Ratna, D. Handbook of Thermoset Resins; iSmithers: Shawbury, UK, 2009. [Google Scholar]
  106. Auvergne, R.; Caillol, S.; David, G.; Boutevin, B.; Pascault, J.-P. Biobased thermosetting epoxy: Present and future. Chem. Rev. 2014, 114, 1082–1115. [Google Scholar] [CrossRef]
  107. Zhao, S.; Abu-Omar, M.M. Renewable thermoplastics based on lignin-derived polyphenols. Macromolecules 2017, 50, 3573–3581. [Google Scholar] [CrossRef]
  108. Kayser, L.V.; Hartigan, E.M.; Arndtsen, B.A. Multicomponent coupling approach to cross-conjugated polymers from vanillin-based monomers. ACS Sustain. Chem. Eng. 2016, 4, 6263–6267. [Google Scholar] [CrossRef]
  109. Holmberg, A.L.; Nguyen, N.A.; Karavolias, M.G.; Reno, K.H.; Wool, R.P.; Epps, T.H. Softwood lignin-based methacrylate polymers with tunable thermal and viscoelastic properties. Macromolecules 2016, 49, 1286–1295. [Google Scholar] [CrossRef]
  110. Holmberg, A.L.; Reno, K.H.; Nguyen, N.A.; Wool, R.P.; Epps, T.H. Syringyl methacrylate, a hardwood lignin-based monomer for high-Tg polymeric materials. ACS Macro Lett. 2016, 5, 574–578. [Google Scholar] [CrossRef] [PubMed]
  111. Sini, N.K.; Bijwe, J.; Varma, I.K. Thermal behaviour of bis-benzoxazines derived from renewable feed stock ‘vanillin’. Polym. Degrad. Stab. 2014, 109, 270–277. [Google Scholar] [CrossRef]
  112. Sun, H.; Young, Y.D.; Kanehashi, S.; Tsuchiya, K.; Ogino, K.; Sim, J.-H. Synthesis and characterization of biobased poly (ether benzoxazole) derived from vanillin. J. Fiber Sci. Technol. 2016, 72, 89–95. [Google Scholar] [CrossRef] [Green Version]
  113. Tachibana, K.; Abe, H. Studies on thermo-mechanical and thermal degradation properties of bio-based polyurethanes synthesized from vanillin-derived diol and lysine diisocyanate. Polym. Degrad. Stab. 2019, 167, 283–291. [Google Scholar] [CrossRef]
  114. Zhao, C.; Huang, C.; Chen, Q.; Ingram, I.D.V.; Zeng, X.; Ren, T.; Xie, H. Sustainable aromatic aliphatic polyesters and polyurethanes prepared from vanillin-derived diols via green catalysis. Polymers 2020, 12, 586. [Google Scholar] [CrossRef] [Green Version]
  115. Shibata, M.; Ohkita, T. Fully biobased epoxy resin systems composed of a vanillin-derived epoxy resin and renewable phenolic hardeners. Eur. Polym. J. 2017, 92, 165–173. [Google Scholar] [CrossRef]
  116. Han, Y.; Tang, D.-H.; Wang, G.-X.; Sun, Y.-N.; Guo, Y.; Zhou, H.; Qiu, W.-F.; Zhao, T. Phthalonitrile resins derived from vanillin: Synthesis, curing behavior, and thermal properties. Chin. J. Polym. Sci. 2020, 38, 72–83. [Google Scholar] [CrossRef]
  117. Amarasekara, A.S.; Garcia-Obergon, R.; Thompson, A.K. Vanillin-based polymers: IV. Hydrovanilloin epoxy resins. J. Appl. Polym. Sci. 2019, 136, 47000. [Google Scholar] [CrossRef]
  118. Zhao, R.; Yong, X.; Pan, M.; Deng, J.; Pan, K. Aldehyde-containing nanofibers electrospun from biomass vanillin-derived polymer and their application as adsorbent. Sep. Purif. Technol. 2020, 246, 116916. [Google Scholar] [CrossRef]
  119. Shuai, L.; Amiri, M.T.; Questell-Santiago, Y.M.; Héroguel, F.; Li, Y.; Kim, H.; Meilan, R.; Chapple, C.; Ralph, J.; Luterbacher, J.S. Formaldehyde stabilization facilitates lignin monomer production during biomass depolymerization. Science 2016, 354, 329–333. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  120. Deuss, P.J.; Scott, M.; Tran, F.; Westwood, N.J.; De Vries, J.G.; Barta, K. Aromatic monomers by in situ conversion of reactive intermediates in the acid-catalyzed depolymerization of lignin. J. Am. Chem. Soc. 2015, 137, 7456–7467. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  121. Lahive, C.W.; Deuss, P.J.; Lancefield, C.S.; Sun, Z.; Cordes, D.B.; Young, C.M.; Tran, F.; Slawin, A.M.Z.; De Vries, J.G.; Kamer, P.C.J.; et al. Advanced model compounds for understanding acid-catalyzed lignin depolymerization: Identification of renewable aromatics and a lignin-derived solvent. J. Am. Chem. Soc. 2016, 138, 8900–8911. [Google Scholar] [CrossRef] [Green Version]
  122. Deuss, P.J.; Lancefield, C.S.; Narani, A.; De Vries, J.G.; Westwood, N.J.; Barta, K. Phenolic acetals from lignins of varying compositions via iron(iii) triflate catalysed depolymerisation. Green Chem. 2017, 19, 2774–2782. [Google Scholar] [CrossRef] [Green Version]
  123. Galkin, M.V.; Samec, J.S.M. Lignin valorization through catalytic lignocellulose fractionation: A fundamental platform for the future biorefinery. ChemSusChem 2016, 9, 1544–1558. [Google Scholar] [CrossRef]
  124. Tarabanko, V.E.; Tarabanko, N. Catalytic oxidation of lignins into the aromatic aldehydes: General process trends and development prospects. Int. J. Mol. Sci. 2017, 18, 2421. [Google Scholar] [CrossRef] [Green Version]
  125. Kim, S.; Tsang, Y.F.; Kwon, E.E.; Lin, K.-Y.A.; Lee, J. Recently developed methods to enhance stability of heterogeneous catalysts for conversion of biomass-derived feedstocks. Korean J. Chem. Eng. 2019, 36, 1–11. [Google Scholar] [CrossRef]
Polymers 13 00364 g001 550
Figure 1. Potential reaction pathway for aerobic oxidation of lignin to vanillin via a series of reactions [37].
Figure 1. Potential reaction pathway for aerobic oxidation of lignin to vanillin via a series of reactions [37].
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Figure 2. Various polymers that can originate from vanillin or syringaldehyde.
Figure 2. Various polymers that can originate from vanillin or syringaldehyde.
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Lee, N.; Kim, Y.T.; Lee, J. Recent Advances in Renewable Polymer Production from Lignin-Derived Aldehydes. Polymers 2021, 13, 364. https://doi.org/10.3390/polym13030364

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Lee N, Kim YT, Lee J. Recent Advances in Renewable Polymer Production from Lignin-Derived Aldehydes. Polymers. 2021; 13(3):364. https://doi.org/10.3390/polym13030364

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Lee, Nahyeon, Yong Tae Kim, and Jechan Lee. 2021. "Recent Advances in Renewable Polymer Production from Lignin-Derived Aldehydes" Polymers 13, no. 3: 364. https://doi.org/10.3390/polym13030364

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