Biobased epoxy resins

Abstract

Disclosed herein are biobased epoxy resin compositions and methods for forming the biobased epoxy resin compositions. The compositions incorporate biobased monomers as alternatives to compositions containing solely petroleum-derived monomers. By incorporating biobased monomers, this invention aims to the reduce the environmental impact and health and safety concerns traditionally associated with the use of exclusively petroleum-derived monomers. In addition to including biobased monomers to replace at least some of the content of more traditionally used petroleum-derived monomers, the disclosed epoxy resin compositions retain key performance characteristics necessary for high performance coating applications and unexpectedly exhibit improved surface hardness, rigidity, and interactions with a metal substrate.

Description

BIOBASED EPOXY RESINSCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 667,020, filed July 2, 2024, which is incorporated by reference herein in its entirety.BACKGROUND

[0002] Epoxy resins are used to produce certain types of high performance coatings. To increase the molecular weight of epoxy resins, the fusion process is often employed. Generally, the fusion process involves heating and reacting a starting low molecular weight epoxy resin with polyfunctional monomers in the presence of a catalyst. Many mid molecular weight and high molecular weight epoxy resins currently available include monomers that are derived from petroleum. For instance, commercial mid molecular weight and high molecular weight epoxy resins commonly include bisphenol A diglycidyl ether (BADGE) upgraded with bisphenol A (BP A). While petroleum-derived monomers are widely used for upgrading epoxy resins due to their satisfactory performance characteristics such as good adhesion and chemical, heat, and wear resistance, customer desires and potential regulatory trends increasingly suggest a market need for epoxy resins that include fewer petroleum products. An epoxy resin that includes biobased monomers and that achieves satisfactory performance is desired.SUMMARY

[0003] This summary is provided to introduce a selection of concepts in a simplified form that are further described herein. This summary is not intended to identify key features or essential features of the claimed subject matter. Nor is this summary intended to be used to limit the scope of the claimed subject matter.

[0004] Disclosed herein are biobased epoxy resin compositions and methods for forming the biobased epoxy resin compositions. The compositions incorporate biobased monomers as alternatives to compositions containing solely petroleum-derived monomers. In addition to including biobased monomers to replace at least some of the content of more traditionally usedpetroleum-derived monomers (e.g., BPA), the disclosed epoxy resin compositions retain key performance characteristics necessary for high performance coating applications and unexpectedly exhibit improved surface hardness, rigidity, and interactions with a metal substrate.

[0005] Both the foregoing summary and the following detailed description provide examples and are explanatory only. Accordingly, the foregoing summary and the following detailed description should not be considered to be restrictive. Further, features or variations may be provided in addition to those set forth herein. For example, certain aspects may be directed to various feature combinations and sub-combinations described in the detailed description.BRIEF DESCRIPTION OF THE FIGURES

[0006] Non-limiting and non-exhaustive examples are described with reference to the following Figures.

[0007] FIG. 1 depicts an example chemical structure of the BADGE epoxy resin component.

[0008] FIG. 2 depicts the chemical structure of the isosorbide biobased monomer.

[0009] FIG. 3 depicts the chemical structure of the vanillyl alcohol biobased monomer.

[0010] FIG. 4 depicts the chemical structure of the vanillic acid biobased monomer.

[0011] FIG. 5. depicts an example generalized reaction scheme for upgrading BADGE with the disclosed biobased monomers.

[0012] FIG. 6 depicts example pKa values in water for the functional groups present within the biobased monomer structures.

[0013] FIG. 7A depicts a line drawing adapted from a photographic image of “webbing” of an example coating with the control epoxy resin of Comparative Example Cl.

[0014] FIG. 7B depicts a line drawing adapted from a photographic image of “webbing” of an example coating with the bio-upgraded epoxy resin of Example 4.

[0015] FIG. 8 depicts an example compression DMA graph with storage modulus as a function of temperature for the bio-upgraded epoxy resin samples from Examples 2, 4, and 6 and control epoxy resin sample from Comparative Example Cl.

[0016] FIG. 9 depicts an example bar chart of the indentation hardness of the bio-upgraded epoxy resins of Example 3-4 and the control epoxy resin of Comparative Example Cl.

[0017] FIG. 10 depicts an example compression DMA graph with storage modulus as a function of temperature for the bio-upgraded epoxy resin of Example 1 and control epoxy resin of Comparative Example C2.DETAILED DESCRIPTION

[0018] In the following detailed description, references are made to the accompanying drawings that form a part hereof, and in which are shown by way of illustrations specific embodiments or examples. These examples may be combined, other examples may be utilized, and structural changes may be made without departing from the present disclosure. Examples may be practiced as methods, systems, or devices. It should be understood that this invention is not limited to the particular methodology, protocols, and reagents, etc., described herein and as such may vary. The terminology used herein is for the purpose of describing particular embodiments only. The following detailed description is therefore not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims and their equivalents.

[0019] To define more clearly the terms used herein, the following definitions are provided. Unless otherwise indicated, the following definitions are applicable to this disclosure. If a term is used in this disclosure but is not specifically defined herein, the definition from the IUPAC Compendium of Chemical Terminology, 2ndEd (1997), can be applied, as long as that definition does not conflict with any other disclosure or definition applied herein, or render indefinite or non-enabled any claim to which that definition is applied. To the extent that any definition or usage provided by any document incorporated herein by reference conflicts with the definition or usage provided herein, the definition or usage provided herein controls.

[0020] Herein, features of the subject matter are described such that, within particular aspects, a combination of different features can be envisioned. For each and every aspect and / or feature disclosed herein, all combinations that do not detrimentally affect the compositions and processes described herein are contemplated with or without explicit description of the particular combination. Additionally, unless explicitly recited otherwise, any aspect and / or feature disclosed herein can be combined to describe inventive features consistent with the present disclosure.

[0021] The processes, systems, and compositions of the present disclosure may comprise, consist essentially of, or consist of the components and ingredients of the present disclosure aswell as other ingredients described herein. As used herein, “consisting essentially of’ means that the methods and compositions may include additional steps, components or ingredients, but only if the additional steps, components or ingredients do not materially alter the basic and novel characteristics of the claimed processes and compositions.

[0022] As used herein, “weight percent,” “wt%,” “percent by weight,” “% by weight,” and variations thereof refer to the concentration of a substance as the weight of that substance divided by the total weight of the composition and multiplied by 100. It is understood that, as used here, “percent,” “%,” and the like are intended to be synonymous with “weight percent,” “wt%,” etc.

[0023] As used herein, “g” represents gram; “L” represents liter; “mg” represents “milligram (10-3 gram);” “mL” represents milliliter (10-3 liter); “cm” represents centimeter (10- 2 meter); micron represents 10-6 meter; “mm” represents millimeter (10-3 meter); “inch” is used as a length unit, and one inch equals to about 2.54 cm; “centipoise” or “cPs” or “cP” is used as a viscosity unit, and 1 cP = 10-3 Pa-s = 1 mPa-s. The temperature unit used herein is degree Celsius (°C).

[0024] The term “about” is used in conjunction with numeric values to include normal variations in measurements, as expected by persons skilled in the art, and is understood to have the same meaning as “approximately” and to cover a typical margin of error, such as ± 10 % of the stated value. The term “about” also encompasses amounts that differ due to different equilibrium conditions for a composition resulting from a particular initial composition. Whether or not modified by the term “about,” the claims include equivalents to the quantities.

[0025] It should be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a composition containing “a compound” includes having two or more compounds that are either the same or different from each other. It should also be noted that the term “or” is generally employed in its sense including “and / or” unless the content clearly dictates otherwise.

[0026] In the interest of brevity and conciseness, any ranges of values set forth in this specification contemplate all values within the range, and are to be construed as support for claims, reciting any sub-ranges having endpoints which are real number values within the specified rangein question. By way of a hypothetical illustrative example, a disclosure in this specification of a range of from 1 to 5 shall be considered to support claims to any of the following ranges: 1-5; 1- 4; 1-3; 1-2; 2-5; 2-4; 2-3; 3-5; 3-4; and 4-5.

[0027] The “epoxide equivalent weight” (EEW) refers to the number of grams of epoxy resin required to give 1 mole of epoxide groups. The EEW may be determined by titration. The EEW standard test method for epoxy content of epoxy resins is ASTM 17 D1652. Weight per Epoxy Equivalent (WPE) may be determined using ASTM D1652 test method.

[0028] Commercially produced mid and high molecular weight epoxy resins typically include monomers that are derived from petroleum. For instance, bisphenol A diglycidyl ether (BADGE) resins have two epoxide groups and can form linear chains or slightly branched structures when reacted with difunctional monomers such as bisphenol A (BPA) through the fusion method. BADGE resins exhibit strong resistance to chemicals and heat, good adhesion properties, and wear resistance, making these resins suitable for certain performance coatings. While BPA upgraded resins, such as BADGE, have many advantageous properties, there are several recognized drawbacks. First, utilization of petroleum-based monomers such as BPA is generally associated with negative environmental, economic, and health concerns. For example, BPA can have estrogenic activity and is a potential endocrine disruptor, raising consumer concerns about its potential health effects. Additionally, increasing regulatory restrictions on the use of BPA suggest a market need for epoxy resins that incorporate fewer petroleum products.

[0029] Thus, an objective of this invention is to develop compositions including a biobased monomer as alternatives to compositions containing solely petroleum-derived BPA monomers. By incorporating a biobased monomer, this invention aims to the reduce the environmental impact and health and safety concerns traditionally associated with the use of exclusively petroleum- derived monomers. In an example, the composition comprises at least 20 wt. % biobased carbon. This means that at least 20% of the total carbon atoms present in the composition are derived from biological sources or materials. Thus, the compositions of the present invention may reduce environmental impact and address health and safety concerns through the inclusion of the biobased monomers disclosed herein. Another objection of this invention is to develop epoxy resin compositions that incorporate biobased monomers and that maintain or exceed the keyperformance properties required of high-performance coatings, previously achieved by BPA upgraded BADGE resins.

[0030] When applied to surfaces or substrates, the epoxy resin compositions of the present invention can form a tough, protective coating. In some examples, the compositions of the present invention can be applied to any suitable surface or substrate before or after curing. For instance, the compositions can be applied to metal containing surfaces or substrates such as aluminum containing surfaces or substrates, iron containing surfaces or substrates, or a surface or substrate that contains a combination of different metals. The epoxy resin compositions of the present invention can be applied onto a surface or substrate by any suitable technique, non-limiting examples of which include, brushing, rolling, pouring, and / or spraying the composition onto the surface or substrate.

[0031] The present invention is directed to epoxy resin compositions that comprise a biobased monomer and methods of forming such epoxy resin compositions. In some examples, the epoxy resin compositions may include between about 10 wt. % and about 50 wt. % of the biobased monomer. In an example, the epoxy resin compositions are formed by combining an epoxy resin component with a catalyst, mixing the combined epoxy resin component and catalyst with a biobased monomer, and upon reaction completion, curing the composition.EPOXY RESIN COMPOSITIONS

[0032] In one example, an epoxy resin composition is disclosed herein. The epoxy resin composition may comprise an epoxy resin component, a catalyst, and a biobased monomer (in some examples, between about 10 wt. % and about 50 wt. % of the biobased monomer).

[0033] Suitable epoxy resin components that may be used in the compositions disclosed herein include, without limitation, a 2+ functional epoxy resin. A 2+ functional epoxy resin generally contains two or more epoxide or glycidyl groups per molecule. Epoxides are threemembered cyclic ethers with an oxygen atom and two carbon atoms. These epoxide groups represent the reactive sites on the epoxy resin component and, due to their reactivity, can undergo polymerization or cross-linking reactions.

[0034] A non-limiting example of a suitable epoxy resin component consistent with examples of this invention, includes but is not limited to, bisphenol A diglycidyl ether (commonly abbreviated BADGE or DGEBA), commercially known as EPON 828. The chemical structure of BADGE contains two epoxide groups at each end of the molecule, as shown in FIG. 1. The epoxide reactive sites present in BADGE are important for forming durable, high-performance coatings and materials.

[0035] The composition of the present invention can contain any suitable catalyst capable of upgrading epoxy resins through the fusion method. The fusion method involves heating the respective reactants in the presence of a catalyst to promote polymerization or cross-linking. This method can be used to increase the molecular weight of the resin by promoting the formation of longer polymer chains. Higher catalyst concentrations and longer reaction times typically lead to higher molecular weights, but these conditions must be balanced to avoid excessive cross-linking, which can result in a brittle material.

[0036] In an example, the catalyst is selected from a group consisting of tetrabutylammonium bromide (TBAB) or ethyltriphenylphosphonium iodide (ETPPI). TBAB is capable of upgrading aromatic alcohols with epoxy functional groups while ETPPI is capable of catalyzing aromatic acids with epoxy functional groups.

[0037] An objection of the present invention is to increase the biobased monomer content of an epoxy resin. Thus, the epoxy resins of the present invention contain between about 10 wt. % and about 50 wt. % of a biobased monomer. In an example, the biobased monomer is an aliphatic biobased monomer. In another example, the biobased monomer is an aromatic biobased monomer. In yet another aspect, the biobased monomer is a liquid. In yet another example, the biobased monomer is a solid. In yet another example, the biobased monomer is synthesized via glycidation of a diol or diacid monomer. Consistent with examples of the present invention, the biobased monomer is selected from the group consisting of isosorbide, vanillyl alcohol, or vanillic acid. These biobased monomers are advantageous for upgrading the disclosed epoxy resin components as their rigidity and aromaticity contribute to excellent toughness and adhesion properties in high- performance coating applications.

[0038] Notably, isosorbide is a cellulosic derivate, making it a sustainable biobased alternative to petroleum-derived monomers. The chemical structure of the isosorbide biobased monomer is depicted in FIG. 2. As shown in FIG. 2, isosorbide is a rigid cycloaliphatic molecule with two fused tetrahydrofuran rings. Based on chemical structure, isosorbide is considered unique as a midpoint between flexible linear aliphatic monomers with low UV susceptibility, and rigid aromatic monomers with high glass transition temperature (Tg) and hardness.

[0039] Isosorbide contains two secondary hydroxyl functional groups that can react with the epoxide groups on the epoxy resin component (e.g., BADGE) in the presence of a catalyst (e.g., TBAB) in a process known as ring-opening polymerization. The generalized reaction scheme for upgrading BADGE with the isosorbide biobased monomer in the presence of TBAB catalyst is depicted in FIG. 5.

[0040] The vanillyl alcohol biobased monomer is a vanillin-derivative, making it also a suitable biobased alternative to petroleum-derived monomers. The chemical structure of vanillyl alcohol is depicted in FIG. 3. As shown in FIG. 3, vanillyl alcohol is a phenolic alcohol, characterized by the presence of both hydroxyl and alcohol functional groups attached to a benzene ring. Advantageously, compared to BPA monomers, vanillyl alcohol contains a greater amount of oxygen within its structure. While not wishing to be bound by theory, by incorporating the vanillyl alcohol biobased monomer into an epoxy resin composition, the carbon-oxygen bonds are increased in the final composition, leading to improvements in adhesion of a coating to a metal surface or substrate, primarily due to the interactions between the metal (e.g., Al, Fe, etc,) and the oxygen contained in the carbon-oxygen bonds. Additionally, the vanillyl alcohol biobased monomers will contribute to solvent resistance when incorporated into an epoxy resin composition due to the pi-stacking ability of the monomer.

[0041] Vanillyl alcohol contains a phenolic hydroxyl group attached to the benzene ring and a primary hydroxyl group attached to the benzyl carbon. These hydroxyl functional groups can react with the epoxide groups on the epoxy resin component (e.g., BADGE) in the presence of a catalyst (e.g., TBAB) in a process known as ring-opening polymerization. The generalized reaction scheme for upgrading BADGE with the vanillyl alcohol biobased monomer in the presence of TBAB catalyst is depicted in FIG. 5.

[0042] Likewise, the vanillic acid biobased monomer is a vanillin-derivative, making it a suitable biobased alternative to petroleum-derived monomers. The chemical structure of vanillic acid is depicted in FIG. 4. As shown in FIG. 4, vanillic acid is a benzoic acid with carboxyl, hydroxyl, and methoxy functional groups attached to a benzene ring. Due to the increased amount of oxygen in its chemical structure, as compared to BPA monomers, and while not wishing to be bound by theory, the vanillic acid biobased monomer can also provide a final epoxy resin composition with improved adhesion of a coating to a metal surface. Like vanillyl alcohol, the vanillic acid biobased monomers will also contribute to solvent resistance when incorporated into an epoxy resin composition due to the pi-stacking ability of the monomer.

[0043] Vanillic acid contains a phenolic hydroxyl group attached to the benzene ring and a carboxyl group attached to the benzene ring. These functional groups can react with the epoxide groups on the epoxy resin component (e.g., BADGE) in the presence of a catalyst (e.g., TBAB) in a process known as ring-opening polymerization. The generalized reaction scheme for upgrading BADGE with the vanillic acid biobased monomer in the presence of ETPPI catalyst is depicted in FIG. 5

[0044] The reactivity trends of the biobased monomers can be compared based on the pKa of their respective reactive groups. The general pKa values in water for the functional groups present within the biobased monomer structures is shown in FIG. 6. The pKa of the functional groups provide a guide to the level of reactivity the biobased molecules will have at the specified reactive sites.

[0045] Generally, the lower the pKa of the functional group, the likelihood that a reaction will occur at the specified location is increased. Specifically for upgrading epoxy resins, the reactivity of the hydroxyl and carboxyl groups help drive the reaction toward completion in which there is full consumption or fully reacted biobased monomer into the epoxy resin component.

[0046] Regarding the vanillic acid biobased monomer, due to the presence of two functional groups with relatively low pKa, the monomer was anticipated to be highly reactive with an epoxy resin component such as BADGE. The pKa values of the functional groups present within the vanillic acid biobased monomer are a pKa of about 10 for the hydroxyl group and a pKa of about 4.2 for the carboxyl group, as shown in FIG. 6.

[0047] On the other hand, it was unexpected that the vanillyl alcohol biobased monomer had the capability to react with an epoxy resin component such as BADGE, due to the presence of two functional groups with higher pKa values. The pKa values of the functional groups present within the vanillyl alcohol biobased monomer are a pKa of about 10 for the hydroxyl group and a pKa of about 15 for the primary hydroxyl group attached to the benzyl carbon, as shown in FIG. 6. It was unexpectedly found that the vanillyl alcohol biobased monomer could react to completion or near completion with about a 50 wt. % loading of monomer with a BADGE epoxy resin component.

[0048] The bio-upgraded epoxy resin compositions of the present invention offer a sustainable alternative to epoxy resins that are upgraded through the use of exclusively petroleum- derived monomers. In an example of the present invention, the composition comprises at least 20 wt. % biobased carbon. The bio-upgraded epoxy resins of the present invention not only retain key performance qualities of BPA upgraded BADGE resins but exhibit further improvements in improved surface hardness and rigidity, as demonstrated in the examples below. Beneficially, the bio-upgraded epoxy resins of the present invention may act as a drop-in replacement for epoxy resins previously upgraded with solely petroleum -derived monomers.METHODS FOR FORMING EPOXY RESIN COMPOSITIONS

[0049] Various methods for forming a biobased epoxy resin composition containing an epoxy resin component, a catalyst, and between about 10 wt. % and about 50 wt. % of a biobased monomer are disclosed and described. A method for forming a biobased epoxy resin composition consistent with examples of this invention may comprise (or consist essentially of, or consist of): combining an epoxy resin component with a catalyst; mixing the combined epoxy resin component and catalyst with a biobased monomer; and upon reaction completion, curing the composition.

[0050] Generally, the features of any of the methods disclosed herein (e.g., the epoxy resin component, the catalyst, the biobased monomer, the reaction completion, and the curing of the composition, among others) are independently described herein, and these features can be combined in any combination to further describe the disclosed methods. Moreover, other method steps can be conducted before, during, and / or after any of the steps listed in the disclosed methods, unless stated otherwise.

[0051] Referring now to the first step of the method, an epoxy resin component is combined with a catalyst. Any suitable epoxy resin component disclosed herein can be utilized. Any suitable amount of epoxy resin component can be utilized, non-limiting ranges of which include from about 50 to about 99 wt. %, from about 60 to about 98 wt. %, from about 70 to about 97 wt.%, or from about 75 to about 96 wt. % epoxy resin component, based on the total weight of the epoxy resin composition. Likewise, any suitable catalyst disclosed herein can combined with the epoxy resin component. Any suitable amount of the catalyst can be utilized, non-limiting ranges of which include from about 0.01 to 20 wt. %, from about 0.05 to 15 wt. %, or from about 0.1 to about 10 wt. % catalyst, based on the total weight of the epoxy resin composition.

[0052] The epoxy resin component and the catalyst can be combined at any suitable temperature. Additionally, the epoxy resin component and catalyst can be combined for any suitable amount of time. Any suitable vessel and conditions can be used for combining the epoxy resin component and the catalyst, and such can be accomplished batchwise or continuously.

[0053] Referring now to the second step of the process, the combined epoxy resin component and catalyst are mixed with a biobased monomer. Any suitable biobased monomer disclosed herein can be mixed with the combined epoxy resin component and any suitable amount of the biobased monomer can be utilized. A representative amount of biobased monomer includes, but is not limited to, from about 1 to about 110 grams, from about 10 to about 100 grams, or from about 20 to about 95 grams of the biobased monomer. Suitable non-limiting ranges for the amount of the biobased monomer include from 1 to 40 wt. %, from 5 to 35 wt. %, or from 5 to 25 wt. % biobased monomer, based on the total weight of the epoxy resin composition.

[0054] Mixing of the combined epoxy resin component and catalyst with the biobased monomer can be performed at any suitable temperature. For example, the temperature for mixing the combined epoxy resin component and catalyst can often fall within a range from 50 °C to 200 °C, from 60 °C to 150 °C, or from 70 °C to 140 °C. In an example, the temperature for mixing the combined epoxy resin component and catalyst is 120 °C. The combined epoxy resin component and catalyst can be mixed with the biobased monomer for any suitable amount of time. For example, the time period for mixing the combined epoxy resin component and catalyst can be, but is not limited to, from about 30 minutes to about 6 hours, from about 45 minutes to about 5 hours,or from about 1 hour to about 4 hours. In an example, the time period for mixing the combined epoxy resin component and catalyst can be from about 1 hour to about 4 hours.

[0055] In an example of the present invention, it is contemplated that the epoxy resin component, the catalyst, and the biobased monomer can be combined to form the epoxy resin composition in one step. Thus, instead of combining the epoxy resin component and the catalyst and then adding the biobased monomer to the combined epoxy resin component and catalyst, the components can be combined all at once in one step. In an example, the epoxy resin component, the catalyst, and the biobased monomer are combined to form the epoxy resin composition at any suitable temperature and time period.

[0056] Referring now to a next step of the method, upon reaction completion, the composition is cured. The reaction is considered complete once the theoretical epoxy equivalent weight (EEW) is attained, or, when there no change in EEW titration value when the value is within about 50 units of the theoretical value over the course of an hour. The EEW is a measure of the number of epoxide groups in an epoxy resin. It is defined as the weight of the resin that contains one equivalent of epoxide groups. For EEW titration, a decrease in EEW indicated that the epoxy groups are reacting with the biobased monomer. When the EEW stabilizes, it suggests that the reaction is complete or has reached equilibrium. By measuring the EEW during titration, one can track the consumption of epoxy groups and determine the progression and completion of the reaction.

[0057] In an example of the present invention, prior to curing the composition, any additional ingredient, filler, or additive can optionally be combined with the epoxy resin composition. In an example, a solvent can be mixed with the composition and the amount of solvent being mixed is based on an amount of solvent necessary to decrease a viscosity of the composition to a predetermined viscosity target.

[0058] In an example of the present invention, the composition can be applied to a surface or substrate before curing the composition. Any suitable surface or substrate can be utilized. For instance, the compositions can be applied to metal containing surfaces or substrates such as aluminum containing surfaces or substrates, iron containing surfaces or substrates, or a surface or substrate that contains a combination of different metals. The epoxy resin compositions of thepresent invention can be applied onto a surface or substrate by any suitable technique, non-limiting examples of which include, brushing, rolling, pouring, and / or spraying the composition onto the surface or substrate.

[0059] The composition can be cured using any suitable curing method. For example, the composition can be cured by increasing the temperature of the reacted mixture incrementally. The composition can be cured at any suitable temperature and for any suitable amount of time. Any suitable curing vessel or reactor can be utilized.

[0060] In a particular example, BADGE is contacted with a TBAB or ETPPI catalyst and then the combined BADGE and TBAB or ETPPI catalyst is mixed with any of the disclosed biobased monomers such as isosorbide, vanillic alcohol, or vanillic acid. The combined BADGE and TBAB or ETPPI and biobased monomer (e.g., isosorbide, vanillic alcohol, or vanillic acid) is mixed for 1 hour to 4 hours at a temperature of 120 °C. Once the reaction is completed (i.e., the theoretical epoxy equivalent weight (EEW) is attained, or, when there no change in EEW titration value when the value is within ~50 units of the theoretical value over the course of an hour), the resulting composition is cured. The final composition is a bio-upgraded epoxy resin composition comprising between about 10 wt. % and 50 wt. % of a biobased monomer, based on the total weight percentage of the epoxy resin composition.EXAMPLES

[0061] The invention is further illustrated by the following examples, which are not to be construed in any way as imposing limitations to the scope of this invention. Various other examples, embodiments, modifications, and equivalents thereof which, after reading the description herein, can suggest themselves to one of ordinary skill in the art without departing from the spirit of the present invention or the scope of the appended claims.

[0062] Molecular weights and molecular weight distributions were obtained by Gel Permeation Chromatography (GPC), and values depended on reaction conditions (heat, time, catalyst) and the weight % of monomer added. Theoretically, increased monomer in the reaction would result in a larger molecular weight, and increased reaction time could result in a shorter MW range.

[0063] Materials analysis of 100% solids bio-upgraded EPON 828 resins was carried out primarily via Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). Solid resin viscosity was determined by DMA.

[0064] Further confirmation of reaction completion was observed using Gas Chromatography-Mass Spectrometer (GCMS) to determine the weight percent of unreacted monomer in the reaction product. For example, GCMS was used to determine the weight percent of vanillyl alcohol in the resulting product based on how much initial vanillyl alcohol was added.EXAMPLES 1-6 AND COMPARITIVE EXAMPLES C1-C2

[0065] The bio-upgraded epoxy resin compositions of Examples 1-6 were prepared according to the following procedures:EXAMPLES 1-2: UPGRADING WITH VANILLIC ACID

[0066] A heating mantle to fit a 3 L reaction vessel, a Friedrich condenser, a temperature probe, and an inert gas line were prepared. To the 4-necked 3 L round-bottom flask, bisphenol A diglycidyl ether (commercially available as EPON 828) (405 g, 185-192 g / eq epoxy equivalent weight) stored at 40 °C, ETPPI catalyst (0.4 g, 0.15 wt %), and vanillyl alcohol (90 g, 0.50 eq or 22 wt %) were combined. The overhead stirring rod was set into the reaction vessel, and stirring began at 154 rpm, then the heating mantle temperature was set to 80 °C. Once the reaction components reached 80°C, the temperature was gradually increased to 130 °C over the course of an hour, at which point, the stir rate was lowered to 140 rpm. The reaction progression was monitored by epoxy equivalent weight (EEW) titration. The reaction continued for 2 more hours, then the hot resin was poured into an aluminum pan to cool and harden overnight. Theoretical EEW= 460 g / eq. Actual EEW= 444 g / eq. GCMS confirmed the final resin to have no residual monomeric vanillic acid. The resin Tg was 40 °C, determined by DSC.EXAMPLES 3-4: UPGRADING WITH VANILLYL ALCOHOL

[0067] A heating mantle to fit a 3 L reaction vessel, a Friedrich condenser, a temperature probe, and an inert gas line were prepared. To the 4-necked 3 L round-bottom flask, bisphenol A diglycidyl ether (commercially available as EPON 828) (414 g, 185-192 g / eq epoxy equivalentweight) stored at 40 °C, TBAB catalyst (0.4 g, 0.1 wt %), and vanillyl alcohol (42 g, 0.25 eq or 10 wt %) were combined. The overhead stirring rod was set into the reaction vessel, and stirring began at 140 rpm, then the heating mantle temperature was set to 140 °C. Once the reaction components reached 140 °C, the temperature was gradually increased to 160 °C. The reaction progression was monitored by epoxy equivalent weight (EEW) titration. After 4 hours, the reaction temperature was increased to 180 °C. After 1 hour, the reaction vessel was removed from heat and allowed to cool for 30 minutes before the resin was poured into a lined quart can. Theoretical EEW= 276 g / eq. Actual EEW= 240 g / eq. GCMS confirmed the final resin to have no residual monomeric vanillyl alcohol.EXAMPLES 5-6: UPGRADING WITH ISOSORBIDE

[0068] A heating mantle to fit a 3 L reaction vessel, a Friedrich condenser, a temperature probe, and an inert gas line were prepared. To the 4-necked 3 L round-bottom flask, bisphenol A diglycidyl ether (commercially available as EPON 828) (401 g, 185-192 g / eq epoxy equivalent weight) stored at 40 °C, TBAB catalyst (0.8 g, 0.2 wt %), and isosorbide (38.8 g, 0.25 eq or 9.8 wt %) were combined. The overhead stirring rod was set into the reaction vessel, and stirring began at 130 rpm, then the heating mantle temperature was set to 100 °C. Once the reaction components reached 100 °C, the stir rate was increase to 140 rpm, and the temperature was gradually increased to 180 °C over the course of 5 hours. The reaction progression was monitored by epoxy equivalent weight (EEW) titration. No increase in EEW was observed in the final 45 minutes of the reaction, prompting the removal of the reaction from heat. At 5 hours into the reaction, the reaction vessel was removed from heat, then after 30 minutes, the resin was poured into a lined quart can. Theoretical EEW= 275 g / eq. Actual EEW= 213 g / eq. GCMS confirmed the final resin to have 4.7-4.9 % monomeric isosorbide by mass.REACTION COMPLETION

[0069] The reaction was considered complete once the theoretical EEW was attained, or alternatively, once there was no change in EEW titration value when the value was within about 50 units of the theoretical value over the course of an hour. Further confirmation of reaction completion was observed using Gas Chromatography-Mass Spectrometer (GCMS) to determinethe weight percent of unreacted monomer in the reaction product. For example, GCMS was used to determine the weight percent of vanillyl alcohol in the resulting product based on how much initial vanillyl alcohol was added. Table 1 below depicts the weight percent of unreacted vanillyl alcohol in the resin products, as determined by GCMS. Table 1 illustrates that for resin product compositions comprising greater than 50 wt % vanillyl alcohol in reaction with EPON 828, in the identical reaction conditions, the amount of unreacted monomer is several orders of magnitude larger than the amount of unreacted monomer for resin product compositions comprising 50 wt % vanillyl alcohol or less. For the resin product compositions comprising greater than 50 wt % vanillyl alcohol, the larger amount of unreacted monomer may lead to undesirable leaching of monomer out of the final coating product.Table 1. GCMS results of unreacted monomer in resin product.POWDER FORMULA PROCESSING

[0070] The Speedmixing process consisted of combining all formula components in a 30 g scale in a 60 g Speedmixing vessel. A capped half-pint metal can containing 10 g of 1 mm ceramic beads was placed in the vessel and sealed with the 60 g lid. The components were then mixed in the Flacktek Speedmixer (available from FlackTek Manufacturing at 486 South Pierce Avenue Louisville, Colorado 80027) at 3500 rpm for 1.5 minutes, then the entire container was placed in cool water bath for 10 minutes. The melted puck of material was removed and then ground to a powder in a 40 g or 10 g vessel in the Speedmixer at 1500 rpm for 30 seconds. The heat processing step and the grinding step were run once more before subject to analysis.

[0071] The upgraded resins were compared to each other by concentration of functionality to indicate level of crosslinking ability, and glass transition temperature (Tg) and viscosity both serve as indicators of ambient physical state and behavior in formulations. Each upgraded epoxy resin composition was compared to a control epoxy resin based on similarity of the EEW values. Comparative Example Cl was the control liquid resin EPON 828 (non-upgraded) used to compare the upgraded biobased liquid resins of Examples 2-6. Comparative Example C2 was the control solid resin DER 6116 (non-upgraded) used to compare the solid vanillic acid upgraded resin of Example 1. Although the EEW of the vanillic acid upgraded resin of Example 1 was roughly 100 g / eq lower, the Tg and viscosity of the vanillic acid upgraded resin of Example 1 and control solid resin of Comparative Example C2 is nearly the same.

[0072] The upgraded epoxy resins of Examples 1, 3, and 5-6 and the control epoxy resins of Comparative Examples C1-C2 were 100% solids. The upgraded epoxy resin of Example 2 was 77% solids and the upgraded epoxy resin of Example 4 was 92% solids. Material analysis of the upgraded and control resins was carried out primarily via Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA), as shown in Table 2 below. For the control epoxy resin of Comparative Example C2 and the upgraded epoxy resin of Example 1, solid resin viscosity was determined by DMA, as shown in Table 2 below.Table 2. Epoxy resin compositions of Examples 1-6 and Comparative Examples C1-C2.

[0073] Clearcoat drawdowns of the amine Ancamine 2422 (EVONIK) with the upgraded epoxy resin compositions of Examples 1-6 and the control epoxy resin of Comparative Example Cl were performed to study the resin properties. However, no surface testing, such as adhesion tests or surface hardness, could be run due to severe “webbing” of the coatings. The “webbing” of the example coating with the control epoxy resin of Comparative Example Cl is depicted in FIG. 7A. The “webbing” of the example coating with the bio-upgraded epoxy resin of Example 4 is depicted in FIG. 7B. There appeared to be an internal tension issue that could be mitigated by the presence of components typically in full formulations such as fillers and solvents. For that reason, the comparison of control and bio-upgraded epoxies was run in full formulations; liquid resins in primer formula, and solid resins in powder formula.

[0074] To obtain some information from the simple two-component system, compression DMA was used to understand the cure behavior of the liquid resins. The compression DMA graph is shown in FIG. 8. Bio-upgraded epoxy resin samples from Examples 2, 4, and 6 and controlepoxy resin sample from Comparative Example Cl were combined with the crosslinker Ancamine 2422 in a FlackTek Speedmixer in a 1 : 1 stoichiometry between epoxy and amine functional groups.

[0075] The cure behavior of the upgraded samples was ruled by epoxy equivalent weight when comparing the upgraded epoxy resin samples of Examples 2, 4, and 6 to the control epoxy resin sample Comparative Example Cl (EPON 828). All upgraded epoxy resins showed a lower crosslinking reaction onset temperature, likely due to their lower functionality to EPON 828.

[0076] Additionally, for the bio-upgraded epoxy resins, the crosslinking reaction onset temperature followed the trends of viscosity as shown in Table 2, where the higher the epoxy resin viscosity, the higher the onset temperature and consequently, the later the reaction onset. In terms of physical properties, the upgraded biobased epoxy resin samples of Examples 2, 4, and 6 and the control epoxy resin sample Comparative Example Cl were ruled by viscosity, where the higher the viscosity, the lower the storage modulus or stiffness of the resulting cured polymer.

[0077] While not wishing to be bound by theory, there seemed to be a direct correlation between chain mobility and storage modulus, where storage modulus behavior was used an indicator of the extent of cure. For example, the control epoxy resin samples of Comparative Example C l has the lowest EEW and molecular weight (MW) of the samples and because it has shorter epoxy chains, it can obtain a more “complete” reaction by being able to navigate the reaction media without being entangled or caged by other epoxy chains. On the other hand, the bio-upgraded epoxy resins of Examples 2, 4, and 6, having higher EEW and MW, are more likely to become entangled by other epoxy chains, or at the very least would need more energy to become sufficiently mobile in the reaction media.

[0078] The vanillyl alcohol bio-upgraded epoxy resin sample of Example 4 and the isosorbide upgraded biobased epoxy resin sample of Example 6 had roughly the same EEW (215 and 219, respectively), but the cured storage modulus of the Example 6 was significantly higher than Example 4. This demonstrates the difference in strength of intermolecular interactions possible of cycloaliphatic molecules and aromatic molecules. The cycloaliphatic isosorbide segments in the bio-upgraded epoxy resin of Example 6 were primarily capable of weak Van der Waals interactions and require less energy for its intramolecular movements. Contrastingly, the aromatic vanillylalcohol segments in the bio-upgraded epoxy resin of Example 4 were capable of stronger Van der Waals forces with pi-stacking with other similar segments as well as BADGE segments. This means that it would take more energy to break the vanillyl alcohol upgraded biobased epoxy resin intermolecular attractions.

[0079] Primer formula R-Cure 200 Dawn Grey (available from Sherwin Williams at 101 West Prospect Ave Cleveland, Ohio 44115) was used to compare the properties of the liquid vanillyl alcohol bio-upgraded epoxy resins of Examples 3-4 to the properties of the control epoxy resin of Comparative Example Cl. The median surface hardness (N / mm2) of the 100 % solids liquid vanillyl alcohol bio-upgraded epoxy resin sample of Example 3 appears to be nearly the same as the control epoxy resin of Comparative Example Cl, 384 N / mm2and 382 N / mm2, respectfully. However, the distribution leans to higher surface hardness values for the liquid vanillyl alcohol bio-upgraded epoxy resin sample of Example 3. Notably, the general breadth of distribution of the results was similar; the liquid vanillyl alcohol bio-upgraded epoxy resins of Examples 3 and the control epoxy resin of Comparative Example Cl both show a comparable amount of irregularity on their surface.

[0080] The 92 % solids liquid vanillyl alcohol bio-upgraded epoxy resin sample of Example 4 contained xylene, which was added as the upgrading reaction cooled resulting in a bio-upgraded epoxy resin with a viscosity resembling that of the control epoxy resin of Comparative Example Cl. Table 3 and FIG. 9 demonstrates how the viscosity of the bio-upgraded epoxy resin samples and the control epoxy resin sample can be determinative when observing the glass transition temperature and surface hardness.Table 3. Primer formula 2ndheat Tg & median nanoindentation results.

[0081] Additionally, the coating hardness of the 92 % solids liquid vanillyl alcohol bioupgraded epoxy resin sample of Example 4 was softer with respect to median compared to both of the other samples, but it the results are still within their distribution of results. However, the narrowness of the distribution of results for 92 % solids liquid vanillyl alcohol bio-upgraded epoxy resin sample of Example 4 indicated a more uniform surface. The softness and uniformity of the bio-upgraded epoxy resin sample of Example 4 was likely due to the presence of solvent in the sample and could change over the span of months. Although the median surface hardness was lower for the bio-upgraded epoxy resin sample of Example 4 than the control epoxy resin sample of Comparative Example Cl, it should also be noted that the grinding step of the 92 % solids sample was difficult to pass the Hegman gauge particle fineness measurement and took several hours longer than was typical compared to the control. The 100 % solids bio-upgraded epoxy resin sample of Example 3, roughly 8 times the viscosity of the control epoxy resin of Comparative Example Cl, handled exceptionally well with a behavior similar to the control Comparative Example Cl in the grind paste process. The bio-upgraded epoxy resin of Example 3 also shared the control sample’s median surface hardness but differed greatly from both the other samples. This may indicate incomplete curing of the sample.

[0082] Notably, the solid vanillic acid resin sample of Example 1 showed Tg and viscosity nearly identical to the higher molecular weight resin of Comparative Example C2 DER 6116, as shown in Table 2. The vanillic acid upgrade was processed as a replacement for DER 6116 with all formula components using a FlackTek Speedmixer. For a more accurate comparison, the DER 6116-containing control formula was also processed using the Speedmixer. The cure behavior of the of the control resin of Comparative Example C2 and bio-upgraded resin of Example 1 were compared via compression DMA, as shown in FIG. 10. Due to the nearly identical glass transition temperature and viscosity of the resins, the main difference was the EEW, with the upgraded resin of Example 1 having higher functionality than the DER 6116 control resin of Comparative Example C2 (444 g / eq and 540 g / eq, respectively). The bio-upgraded resin, due to its greater capacity to crosslink, resulted in a stiffer cure than the control formula as seen in the rubbery plateau regions of the storage modulus for the samples.

[0083] For the purposes of this application, directional terms such as “upper,” “lower,” “upward,” and “downward” are intended to be descriptive with reference to the disclosure above and, where applicable, in relation to the orientation shown in the Figures for clarity. The examples as practiced and included in the scope of the claims may include examples where the systems and devices are in a different orientation.

[0084] While particular uses of the technology have been illustrated and discussed above, the disclosed technology can be used with a variety of environments in accordance with many examples of the technology. The above discussion is not meant to suggest that the disclosed technology is only suitable for implementation within the environments shown and described above. As should be appreciated, the various aspects described with respect to the figures herein are not intended to limit the technology to the particular aspects described. Accordingly, additional configurations can be used to practice the technology herein and / or some aspects described can be excluded without departing from the methods and systems disclosed herein.

[0085] This disclosure described some aspects of the present technology with reference to the accompanying drawings, in which only some of the possible aspects were shown. Other aspects can, however, be embodied in many different forms and should not be construed as limited to the aspects set forth herein. Rather, these aspects were provided so that this disclosure was thorough and complete and fully conveyed the scope of the possible aspects to those skilled in the art.

[0086] Similarly, where operations of a process are disclosed, those operations are described for purposes of illustrating the present technology and are not intended to limit the disclosure to a particular sequence of operations. For example, the operations can be performed in differing order, two or more operations can be performed concurrently, additional operations can be performed, and disclosed operations can be excluded without departing from the present disclosure. Further, each operation can be accomplished via one or more sub-operations. The disclosed processes can be repeated.

[0087] Although specific aspects were described herein, the scope of the technology is not limited to those specific aspects. One skilled in the art will recognize other aspects or improvements that are within the scope of the present technology. Therefore, the specific structure, acts, or operations are disclosed only as illustrative aspects. The scope of the technologyis defined by the following claims and any equivalents therein. Examples of the disclosure may be described according to the following aspects.

[0088] Aspect 1. A composition, comprising: an epoxy resin component; a catalyst; and between about 10 wt. % and about 50 wt. % of a biobased monomer.

[0089] Aspect 2. The composition of aspect 1, wherein the epoxy resin component comprises a 2+ functional epoxy resin.

[0090] Aspect 3. The composition of any of aspects 1-2, wherein the catalyst comprises is selected from the group consisting of TBAB or ETPPI.

[0091] Aspect 4. The composition of any of aspects 1-3, wherein the biobased monomer comprises a 2+ functional monomer.

[0092] Aspect 5. The composition of any of aspects 1-4, wherein the biobased monomer is selected from the group consisting of isosorbide, vanillyl alcohol, or vanillic acid.

[0093] Aspect 6. The composition of any of aspects 1-5, wherein the biobased monomer is an aliphatic biobased monomer.

[0094] Aspect 7. The composition of any of aspects 1-6, wherein the biobased monomer is an aromatic biobased monomer.

[0095] Aspect 8. The composition of any of aspects 1-7, wherein the biobased monomer is a liquid.

[0096] Aspect 9. The composition of any of aspects 1-7, wherein the biobased monomer is a solid.

[0097] Aspect 10. The composition of any of aspects 1-9, wherein the composition comprises at least 20 wt. % biobased carbon.

[0098] Aspect 11. The composition of any of aspects 1-10, wherein the biobased monomer is synthesized via glycidation of a diol or diacid monomer.

[0099] Aspect 12. The composition of any of aspects 1-11, further comprising a solvent.

[0100] Aspect 13. A method of forming a composition, comprising: combining an epoxy resin component with a catalyst; mixing the combined epoxy resin component and catalyst with a biobased monomer; and upon reaction completion, curing the composition.

[0101] Aspect 14. The method of aspect 13, wherein the composition is cured by ramping temperature from 25°C to 150°C at a ramp rate of 5°C per minute.

[0102] Aspect 15. The method of any of aspects 13-14, further comprising: prior to curing the composition, mixing a solvent with the composition, the amount of solvent being mixed being based on an amount of solvent necessary to decrease a viscosity of the composition to a predetermined viscosity target.

[0103] Aspect 16. The method of any of aspects 13-15, wherein the mixing of the combined epoxy resin component and catalyst with a biobased monomer occurs at a temperature of 120°C for between about 1 hour and 4 hours.

[0104] Aspect 17. The method of any of aspects 13-16, wherein the biobased monomer comprises between about 10 wt. % and about 50 wt. % of the composition.

Claims

What is claimed is:

1. A composition, comprising: an epoxy resin component; a catalyst; and between about 10 wt. % and about 50 wt. % of a biobased monomer.

2. The composition of claim 1, wherein the epoxy resin component comprises a 2+ functional epoxy resin.

3. The composition of any of claims 1-2, wherein the catalyst comprises is selected from the group consisting of TBAB or ETPPI.

4. The composition of any of claims 1-3, wherein the biobased monomer comprises a 2+ functional monomer.

5. The composition of any of claims 1-4, wherein the biobased monomer is selected from the group consisting of isosorbide, vanillyl alcohol, or vanillic acid.

6. The composition of any of claims 1-5, wherein the biobased monomer is an aliphatic biobased monomer.

7. The composition of any of claims 1-6, wherein the biobased monomer is an aromatic biobased monomer.

8. The composition of any of claims 1-7, wherein the biobased monomer is a liquid.

9. The composition of any of claims 1-7, wherein the biobased monomer is a solid.

10. The composition of any of claims 1-9, wherein the composition comprises at least 20 wt. % biobased carbon.

11. The composition of any of claims 1-10, wherein the biobased monomer is synthesized via glycidation of a diol or diacid monomer.

12. The composition of any of claims 1-11, further comprising a solvent.

13. A method of forming a composition, comprising: combining an epoxy resin component with a catalyst; mixing the combined epoxy resin component and catalyst with a biobased monomer; and upon reaction completion, curing the composition.

14. The method of claim 13, wherein the composition is cured by ramping temperature from 25°C to 150°C at a ramp rate of 5°C per minute.

15. The method of any of claims 13-14, further comprising: prior to curing the composition, mixing a solvent with the composition, the amount of solvent being mixed being based on an amount of solvent necessary to decrease a viscosity of the composition to a predetermined viscosity target.

16. The method of any of claims 13-15, wherein the mixing of the combined epoxy resin component and catalyst with a biobased monomer occurs at a temperature of 120°C for between about 1 hour and 4 hours.

17. The method of any of claims 13-16, wherein the biobased monomer comprises between about 10 wt. % and about 50 wt. % of the composition.

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