EP4652214A1

EP4652214A1 - Biobased amine-curatives and polyurea compositions

Info

Publication number: EP4652214A1
Application number: EP24701795.7A
Authority: EP
Inventors: Juan Jesus Burdeniuc; Jared Denis Bender; Jingguo Shen; Kristen MINNICH
Original assignee: Evonik Operations GmbH
Current assignee: Evonik Operations GmbH
Priority date: 2023-01-20
Filing date: 2024-01-17
Publication date: 2025-11-26
Also published as: CN120569421A; WO2024153653A1; KR20250135279A; JP2026503555A

Abstract

The present invention relates to a low carbon footprint (LCF) amine curative composition characterized by the presence of ¹⁴C radiocarbon isotope, a LCF polyurea composition, a method of making the LCF-amine curative composition, and a method of making the LCF polyurea composition.

Description

TITLE OF THE INVENTION: BIOBASED AMINE-CURATIVES AND POLYUREA COMPOSITIONS

FIELD OF THE INVENTION

[0001] The field of invention is novel low carbon footprint (LCF) polyurea compositions and a LCF-amine curative composition characterized by the presence of ¹⁴C radiocarbon isotope. The field of the invention is also a product by process where the LCF-curative is prepared utilizing a raw material made by fermentation of biomass. The field of the invention is also a method to make polyurea polymers in which a significant part of the raw materials have very low emission of green house gases into the environment. The LCF-amine curative is used to make polyurea polymers by the reaction with an organic isocyanate. The LCF-amine curative and the isocyanate have each at least two functional groups. The LCF-curative is preferably an organic diamine that has been produced with sustainable biobased raw materials having a low carbon foot print in which the process employed for the manufacturing of the curative substantially reduces green house gases emissions.

BACKGROUND OF THE INVENTION

[0002] Alkanediol-p-diaminobenzoate diesters have been used as curatives for preparing polyureas. These curatives can be prepared in a number of different processes and the prior art is described below.

[0003] One representative family of curatives used in the manufacturing of polyureas is obtained when petrochemical based polytetramethylene ether glycol (PTMEG) of various molecular weights are esterified at each of their two-terminal hydroxyl group with p- aminobenzoic acid (PABA) to yield a bi-functional amine curative. When these curatives are reacted with difunctional or polyfunctional isocyanates they can produce polyurea films with good mechanical properties providing high performance in abrasion resistance and toughness.

[0004] Existing methods for the preparation of petrochemical based aromatic amine curatives described in the prior art utilize exclusively raw materials and processes that are carbon intensive putting stress on the environment by the large emission of carbon dioxide generated during their manufacturing as well as by the depletion of irreplaceable fossil fuels. Some of these prior methods are described in the following documents. [0005] US Pat. 3932360 discloses the preparation of petrochemical based diamine cured polyurethane products by combining an isocyanate terminated urethane prepolymer with a compound of the formula: wherein X is a 2-12 carbon alkylene or cycloalkylene group. The products have zero ¹⁴C content made exclusively from fossil fuel based materials.

[0006] US Pat. 4283549 discloses a method of producing petrochemical based alkanediol-diaminobenzoate esters which includes esterifying nitro-benzoic acid and certain diols in a melt and then dissolving the intermediate in a solvent sparingly soluble in water such as an aromatic hydrocarbon, an ether or an ester and reducing with hydrogen gas. The products have zero ¹⁴C content being made exclusively from fossil fuel based materials and at least twice as much emissions of greenhouse gases when compared with the new invention.

[0007] US Pat 4476318 discloses a process for the preparation of petrochemical based 1 ,3-propanediol bis(p-aminobenzoate) obtained by reacting the alkali metal salt of p- aminobenzoic with dihalogenated propane in an aprotic polar solvent. In accordance with this process, diesterification is said to proceed under mild conditions without causing any undesirable side reactions and to provide 1 ,3-propanediol bis(p-aminobenzoate) diester in high purity and high yield. The products have zero ¹⁴C content being made exclusively from fossil fuel based materials with no environmental benefits relative to the new invention.

[0008] US Pat 6111129 discloses a process for the direct preparation of alkanediol- diaminobenzoate diesters comprising transesterifying an alkyl-p-aminobenzoate with a diol in the presence of a transesterification catalyst. No ¹⁴C content is present in these products as they are prepared exclusively from fossil fuel based materials.

[0009] EP 0677542 A2 discloses petrochemical based polyurethane-urea elastomers that are made using 2-methyl-1 ,3-propanediol-bis-p-aminobenzoate, which is the reduction product from hydrogenating 2-methyl-1 ,3-propanediol-bis-p-nitrobenzoate. The latter composition is preferably made by esterifying p-nitrobenzoic acid and 2-methyl-1 ,3- propanediol using a stoichiometric excess of the diol to promote the esterification process followed by further reaction with the acid, removal of the volatile free diol while continuing the esterification of unreacted acid and transesterification of the monoester formed to diester. This process, is claimed to be applicable broadly to esterification of other nitroaromatic acids with other aliphatic diols and also to produce high yields of diester without needing extraneous solvent for processibility and with only water as a byproduct. The products have zero ¹⁴C content being made exclusively from fossil fuel based materials.

[0010] The curatives provided by all the above processes are petrochemical based materials having zero ¹⁴C radiocarbon content and made exclusively from fossil fuel based materials with process disadvantages such as at least double the emission of greenhouse gases when compared with the process of the new invention.

[0011] Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

BRIEF SUMMARY OF THE INVENTION

[0012] The invention relates to aromatic amine curing agents that can be produced using chemical processes that have positive carbon footprint (carbon dioxide uptake from the atmosphere), neutral carbon footprint (no emission or release of carbon dioxide into the atmosphere) or minimal carbon footprint (minimal to no emission of carbon dioxide into the atmosphere). The new aromatic amine curing agent should also provide polyurea compositions comprising the reaction product of an organic isocyanate and an organic amine, each having at least two functional groups are disclosed. The polyurea compositions while satisfying the requirement of no-carbon or low carbon footprint should also be able to provide polyurea polymer with optimum physical and chemical properties.

[0013] The new LCF-amine curative as well as the resulting polyurea polymers are characterized by the presence of ¹⁴C radiocarbon isotope. The biocarbon content is based on the amount of biogenic carbon present and defined as the amount of biocarbon in the material/product as fraction of the weight or mass or percent weight or percent mass of the total organic carbon in the material/product. This determination of the percentage content of biocarbon is typically obtained using the ASTM D6866 method. In this method, the % of biobased carbon content = [bio(organic) carbon/total organic carbon] x 100. The ASTM D6866 is a standard test method for determining the biobased content of solid, liquid, and gaseous samples using radiocarbon analysis. [0014] Carbon is the main element that is the building block of polymeric materials, fuels and living organisms. There is increasing concerns over the growing of CO₂ emissions released into the environment from human activity with no additional fixation and removal of the released CO₂. Reducing our carbon footprint and addressing the carbon cycle imbalance is one of the main challenges facing modern human society. The use of renewable biobased chemical feedstocks to manufacture plastics and products provides an alternative pathway towards a zero or neutral carbon footprint value proposition.

[0015] The concentration of carbon dioxide in the atmosphere is about 380 ppm. The heat retained in the atmosphere will increase if the concentration of CO₂ begins to increase above this value leading to global warming that can threaten life because of increasing man made carbon (CO₂) and other heat trapping gas emissions released into the atmosphere. Thus, there is no disagreement that uncontrolled and continued increase in levels of CO₂ in the atmosphere will lead to global warming bringing a negative impact on life.

[0016] Therefore, it is necessary to prevent the level of CO₂ to increase using the zero carbon emissions approach. While the fixation of CO₂ from air to form petroleum/fossil feedstocks is typically measured in millions of years the time scale for its end of life and release into the environment is in 1-10 years. Thus, it is not sustainable if the CO₂ release due to human activity is much larger than the rate of fixation. This leads to an increase in carbon emissions and with it the collateral effect of global warming and climate change. By using renewable biomass crops as feedstocks to manufacture our carbon based products the CO₂ released at the end-of-life of the product is captured by planting new crops or biomass plantations. Specifically, the rate and time scales of CO₂ release to the environment at end of life equals the rate of photosynthesis that captures CO₂ converting into biomass for the next generation of products with a net zero carbon footprint.

[0017] Biobased materials may contain 100% biogenic carbon witch contains ¹⁴C radiocarbon isotope or be mixed (physically, chemically, or biologically) with fossil/petroleum based carbon. Therefore, one needs to define biobased content by the amount of biogenic carbon present in the product. Measuring the ¹⁴C isotope content forms the basis for identifying and quantifying the amount of biboased material. The CO₂ in the atmosphere is in equilibrium with radioactive ¹⁴CO₂. Radioactive carbon is formed in the upper atmosphere through the effect of cosmic ray neutrons on ¹⁴N. Then it is oxidized to radioactive ¹⁴CO₂ entering through photosynthesis to plant life and subsequently the animal life. Plants and animals use carbon foodchains taking up ¹⁴C during their life spans. Living organisms exist in equilibrium with the ¹⁴C concentration of the atmosphere and non-radioactive carbon atoms stay approximately the same over time.

[0018] When a plant or animal dies their metabolic function stops carbon uptake and radiocarbon ¹⁴C is not replaced with its concentration slowly decaying. Since the half life of carbon is around 5730 years, the fossil feedstocks formed over millions of years will have no ¹⁴C present. Therefore, using this methodology it is possible to identify and quatify biobased content which has beed standardized using the ASTM D6866. This method involves the combustion of the test material with oxygen to produce carbon dioxide gas. The gas is then analyzed to provide a measure of the products ¹⁴C/¹²C content and relative to the modern carbon based oxalic acid radiocarbon Standard Reference Material (SRM) 4990c that is 100 % biocarbon. Three different methods can be used to obtain the ¹⁴C/¹²C ratio as described in the Standard ASTM D6866. The most accurate method of determining ¹⁴C/¹²C ratios is by magnetic accelerator mass spectrometry which is able to provide a measurement with approximately 3 % uncertainty.

[0019] Thus, the present invention relates to a LCF-amine curative composition comprising at least one compound with the formula: where n = 1-40 and more preferably n = 1-30, having a % of biomass content ranging from 100 % to 10 % and preferably 100% to 50% and more preferably 90% to 50% as measured by the presence of the ¹⁴C isotope using the ASTM D6866 method and prepared using ¹⁴C containing biobased 1 ,3-propylenediol and/or poly(1 ,3-propylenediol) with MW in the range of 76 g/mol to 3040 g/mol and preferably 76 g/mol to 2280 g/mol, where 1 ,3-propylenediol and/or poly(1 ,3-propylenediol) are produced by fermentation of biomass and/or polycondensation of 1 ,3-propylenediol obtained by fermentation of biomass. Furthermore, the new composition also discloses a unique distribution of isomers as denoted by the ranges of “n” in the formula such that the curative remains liquid, or formation of solids does not occur for a long period of time, resulting essentially in liquid amine curatives without the need of providing heat for melting resulting in improved processing. DEFINITIONS

[0020] The following definitions are provided in order to aid those skilled in the art in understanding the detailed description of the present invention.

PPDO: Poly-1 , 3-propylenediol

PABA: Para-aminobenzoic acid

PTMEG: Poly-tetramethylene glycol

LCF: Low carbon footprint

DETAILED DESCRIPTION OF THE INVENTION

[0021] The invention is directed to a LCF-amine curative composition comprising at least one compound with the formula: where n = 1-40, having a % of biomass content ranging from 100 % to 10 % as measured by the presence of the ¹⁴C isotope using the ASTM D6866 method and prepared using ¹⁴C containing biobased 1 ,3-propylenediol and/or poly(1 ,3-propylenediol) with MW in the range of 76 g/mol to 3040 g/mol, where 1 ,3-propylenediol and/or poly(1 ,3-propylenediol) are produced by fermentation of biomass and/or polycondensation of 1 ,3-propylenediol obtained by fermentation of biomass. Preferably in one embodiment, the at least one compound has n = 1-30. Preferably in one embodiment, the at least one compound has a % of biomass content ranging from 100 % to 50 % as measured by the presence of the ¹⁴C isotope using the ASTM D6866 method. Preferably in another embodiment, the at least one compound has a % of biomass content ranging from 90 % to 50 % as measured by the presence of the ¹⁴C isotope using the ASTM D6866 method. Preferably in one embodiment, the at least one compound is prepared using ¹⁴C containing biobased 1 ,3-propylenediol and/or poly(1 ,3- propylenediol) with MW in the range of 76 g/mol to 2280 g/mol. Furthermore, the new composition also discloses a unique distribution of isomers as denoted by the ranges of “n” in formula (I) such that the curative remains liquid, or formation of solids does not occur for a long period of time, resulting essentially in liquid amine curatives without the need of providing heat for melting resulting in improved processing.

[0022] In another embodiment the invention relates to a product by process in which biobased or optionally non-biobased p-aminobenzoic acid or a p-aminobenzoic acid ester is contacted with biobased 1 ,3 propanediol or biobased poly(1 ,3 propanediol) and the mixture was dried with toluene excess with a Dean Stark apparatus prior to adding a metal catalyst Ti(BuO)₄ to the toluene containing mixture and increasing the temperature to compete the esterification to about 99% to give the biobased amine-curative 1 ,3- propyleneglycolbis(4-aminobenzoate) or poly-(1 ,3-propyleneglycol)bis(4- aminobenzoate).

[0023] The amine-curatives can be produced using chemical processes that have negative carbon footprint (carbon dioxide uptake from the atmosphere), neutral carbon footprint (no net emission or release of carbon dioxide into the atmosphere) or positive carbon footprint (minimal emission of carbon dioxide into the atmosphere).

[0024] In another embodiment, the invention relates to a LCF polyurea composition comprising the reaction of at least one isocyanate and a LCF-amine curative composition comprising at least one compound with the formula: where n = 1-40 and more preferably n = 1-30, having a % of biomass content ranging from 100 % to 10 % and preferably 100% to 50% and more preferably 90% to 50% as measured by the presence of the ¹⁴C isotope using the ASTM D6866 method and prepared using ¹⁴C containing biobased 1 ,3-propylenediol and/or poly(1 ,3-propylenediol) with MW in the range of 76 g/mol to 3040 g/mol and preferably 76 g/mol to 2280 g/mol, where 1 ,3-propylenediol and/or poly(1 ,3-propylenediol) are produced by fermentation of biomass and/or polycondensation of 1 ,3-propylenediol obtained by fermentation of biomass.

[0025] In another embodiment, the invention relates to a method of making a LCF polyurea composition comprising contacting at least one diisocyanate or polyisocyanate with a LCF-amine curative composition comprising at least one compound with the formula: where n = 1-40 and more preferably n = 1-30, having a % of biomass content ranging from 100 % to 10 % and preferably 100% to 50% and more preferably 90% to 50% as measured by the presence of the ¹⁴C isotope using the ASTM D6866 method and prepared using ¹⁴C containing biobased 1 ,3-propylenediol and/or poly(1 ,3-propylenediol) with MW in the range of 76 g/mol to 3040 g/mol and preferably 76 g/mol to 2280 g/mol, where 1 ,3-propylenediol and/or poly(1 ,3-propylenediol) are produced by fermentation of biomass and/or polycondensation of 1 ,3-propylenediol obtained by fermentation of biomass.

[0026] In another embodiment, the invention relates to a method of making a LCF polyurea polymer by contacting the biobased amine-curative 1 ,3-propyleneglycolbis(4- aminobenzoate) or poly-(1 ,3-propyleneglycol)bis(4-aminobenzoate) with a diisocyanate or polyisocyanate to give a polyurea polymer.

[0027] The polyureas of the invention are prepared by reacting at least one organic isocyanate and the amine-curative composition. Preferably, the at least one organic isocyanate is a di-isocyanate or polyisocyanate. Preferably, the di-isocyanate or polyisocyanate is an aliphatic isocyanate, arylaliphatic isocyanate, or aromatic isocyanate selected from hexamethylene diisocyanate, isophorone diisocyanate, phenylene diisocyante, toluene diisocyanate (TDI), diphenyl methane diisocyanate isomers (MDI), hydrated MDI and 1 ,5-naphthalene diisocyanate.

[0028] Preferred examples of aliphatic isocyanates which may be employed include but are not limited to polymethylene diisocyanates such as ethylene diisocyanate, propylene- 1 ,2-diisocyanate, tetramethylene-1 ,4-diisocyanate, hexamethylene- 1 ,6 diisocyanate, dodecane-1 ,12-diisocyanate and the like. Also, cycloaliphatic isocyanates such as dicyclohexylmethane diisocyanate, cyclobutane- 1 ,3-diisocyanate, cyclohexane- 1 ,4- diisocyanate, cyclohexane-1 ,3-diisocyanate and mixtures of these isomers, 1- isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane and the like. Arylaliphatic diisocyanates such as 1 ,3-xylene diisocyanate; perchlorinated aryl polyisocyanates, polyphenylpolymethylene polyisocyanates obtained by aniline formaldehyde condensation followed by phosgenation, m and p-isocyanatophenyl-sulphonyl isocyanates and the like. [0029] Preferred aromatic isocyanates which may be used in the invention include 3,3'- dimethyl-4,4'-biphenylene diisocyanate (o-tolidine diisocyanate, TODI), toluene-2,4- or 2,6-diisocyanate (TDI) and mixtures of these isomers such as a mixture of 80% 2,4- toluene diisocyanate and 20% 2,6-toluene diisocyanate; phenylene1 ,4-diisocyanate; diphenylmethane-2,4'-diisocyanate; diphenylmethane- 4,4'-diisocyanate (MDI); diphenyl ether 4,4'-diisocyanate; naphthylene- 1 ,5-diisocyanate (NDI); p-phenylene diisocyanate (PPDI); p,p-diphenyl diisocyanate; hexahydrophenylene-1 ,3-diisocyanate; hexahydrophenylene-1 ,4-diisocyanate; triphenylmethane- 4,4'4"-triisocyanate; perhydrodiphenylmethane-2,4'-diisocyanate; perhydrodiphenylmethane-4,4'-diisocyanate and the like, preferably MDI. Other preferred isocyanates which may be employed include polyisocyanates having carbodiimide groups; polyisocyanates having allophanate groups; polyisocyanates having isocyanurate groups; polyisocyanates having urea groups; polyisocyanates having acylated urea groups; polyisocyanates having biuret groups; polyisocyanates prepared by telomerization reactions; polyisocyanates having ester groups; reaction products of the above-mentioned isocyanates with acetals; and polyisocyanates containing polymeric fatty acid groups; isophorone diisocyanate and ester diisocyanates of carboxylic acids of the kind described in EP0269869A2 triisocyanates such as, p.p',p"-triphenyl methane triisocyanate also may be used.

[0030] The polyurea compositions while satisfying the requirement on no-carbon or low carbon footprint should also be able to provide polyurea polymer with optimum physical and chemical properties. The products are also characterized by the presence of ¹⁴C content which can be measured using ASTM D6866.

[0031] In one embodiment of the invention, the amine-curative composition of the present invention further comprises at least one amine co-curative made exclusively from fossil fuel based materials having zero ¹⁴C content. A broad range of amine cocurativemay be employed. Choice of amine co-curative will affect the hardness attained in the polyurea product. Preferably, the at least one amine co-curative is an organic diamine or organic triamine. Preferably in another embodiment, the at least one amine co-curative is an aromatic diamine. Preferably, the amine co-curativeis seleced from the group consisting of polymethylene-di-p-aminobenzoates, polyethyleneglycolbis(4- aminobenzoate) and the like. Preferably, the aromatic diamine is seleced from the group consisting of A) a polymethylene-di-p-aminobenzoate with the formula: where X=2-12 carbon alkylene or cycloalkylene groups, where the alkylene and cycloalkylene groups represented by X may be substituted or unsubstituted, suitable substituents include 1-5 carbon alkyl groups, halogenpreferably chloro or fluoro, and aryl groups preferably phenyl;

B) a polyethyleneglycol-bis(4-aminobenzoate) with the formula: where n=2-4;

C) a polydimethylsiloxane-bis(4-aminobenzoate) with the formula: where n=2-4; and

D) a polytetramethyleneetherglycol-di-p-aminobenzoate with the formula: where n=1-40.

[0032] In addition to the negative environmental impact, the use of the petrochemical based PTMEG-based aromatic diamines also have some limitations in relation to its physical state. PTMEG is well known to have a high Tg and forms an amorphous solid, and when curatives are made via esterification with p-aminobenzoic acid then solidification is very likely limiting its utility. Among commercially available curatives made with PTMEG and PABA only one has a melting point below 15°C while most of them are solids at ambient temperature. Although the products can be heated during ambient temperature processing, any application requiring storage as in the case of polyurea coatings and adhesives will lead to solid phase separation making the manufacturing operation more complex.

[0033] In some applications, polyurea polymers are used over polyurethane polymers because the former typically have higher mechanical performance where high abrasion resistance and toughness is needed. System manufacturers currently use PTMEG based curatives because of the physical property benefits even though challenges remain because the PTMEG-based aromatic diamine made from PABA are very viscous and are typically solids or tend to solidify over time.

[0034] Another main disadvantage of PTMEG based curatives is the energy intensive processes and raw materials utilized in its manufacturing processes. PTMEG is made by the acid-catalyzed polymerization of tetrahydrofuran. Tetrahydrofuran is commercially made from fossil fuels starting with natural gas which is converted to acetylene. The acetylene is then reacted with formaldehyde to make butynediol which is further hydrogenated to butanediol. Butanediol is then converted into tetrahydrofuran by the action of a catalyst. This process to make PTMEG is not only energy intensive causing large emission of greenhouse gases but it also employs non-renewable resources.

[0035] The new biobased curatives of the invention are characterized by having either low or no carbon footprint (no release of CO₂ into the environment) or negative carbon footprint impact (net uptake of CO₂ from the environment). The new amine curative composition is characterized by the presence of ¹⁴C radiocarbon isotope, which is completely absent in petrochemical-based curatives, where the concentration of ¹⁴C radiocarbon is zero. The new biobased curatives of the invention are made with precursors obtained, for example, by bacterial fermentation of plant based glucose using a process that is essentially carbon neutral so the overall amine curative process is more energy efficient with substantially low emission of green house gases.

[0036] Thus, as an example, the present invention illustrates the use of corn-based 1 ,3-propanediol and related substances obtained by the oligomerization and polymerization of 1 ,3-propane diols to give poly-1 ,3-propanediols which are used to synthesize the LCF-amine curatives of the invention. Biobased 1 ,3-propanediol is typically obtained by a fermentation process of plant derived glucose instead of using petroleoum based feedstocks.

[0037] The present invention provides new curing agents made via the esterification of biobased 1 ,3-propanediol or biobased poly(1 ,3-propanediol) with PABA to make biobased aromatic diamines that can provide abrasion resistance polyureas comparable to those made using petrochemical. Surprisingly, the biobased poly-1 , 3- propanediol/PABA diester amines are liquid at room temperature and therefore are easier to use in applications where conventional PTMEG diamines cannot be used because of their high melting point and difficult processability.

[0038] Optionally, the present invention provides new LCF-amine curatives made via the esterification of biobased 1 ,3-propanediol or biobased poly(1 ,3-propanediol) with biobased PABA produced by bacterial fermentation of biomass including sugars to make biobased aromatic diamines that can provide abrasion resistance polyureas comparable to those made using petrochemical.

[0039] Oligomeric diamines LCF-curatives made via esterification of PABA and/or optionally biobased-PABA with biobased poly-1 , 3-propanediol (PPDO) of three different molecular weights of ~650, ~1000, and ~2000 results surprisingly in products that are liquid at room temperatures. The time window for these curatives to remain liquid is much longer than with conventional PTMEG curatives eliminating the need for heating when the new LCF-curatives made from biobased PPDO are used. Thus, while a typical PTMEG/PABA curative with approximate MW of 2000 is a solid at room temperature (mp.~36°C) the corresponding similar product made with biobased-PPDO/PABA with approximately the same MW (~2000) is liquid at room temperature. A similar case is for MW ~1000 for which the biobased-PPDO/PABA curatives are liquid at room temperature while the corresponding PTMEG/PABA curatives are hazy liquids due to partial solidification. Only for low MW (~650) both the biobased-PPDO/PABA and the PTMEG/PABA are liquids at room temperature albeit the biobased-PPDO/PABA curatives have lower viscosity.

[0040] Due to the global concerns regarding climate change and the impact of emissions of global warming gases into the environment the chemical industry is transitioning towards a more circular economy where chemical processes are designed to minimize the impact on the environment as measured, for example, by the carbon footprint of the new chemical processes. Thus, there is a need for new environmentally friendly chemical processes able to provide chemical products with minimal or no impact in the environment. In accordace with these needs, the present invention provided new LCF-amine curative compositions characterized by the presence of ¹⁴C radiocarbon isotope in its composition. The present invention also provide a product by process where the new curatives are made using fully or partial biobased raw materials with low or no carbon footprint. In addition, the present invention provides a method to to make these new LCF-amine curatives.

[0041] The following invention is directed to the following aspects: <1> A LCF-amine curative composition comprising at least one compound with the formula: where n = 1-40, having a % of biomass content ranging from 100 % to 10 % as measured by the presence of the ¹⁴C isotope.

<2> The LCF-amine curative composition of aspect <1>, where the at least one compound has n = 1-30.

<3> The LCF-amine curative composition of aspect <1> or <2>, where the at least one compound has a % of biomass content ranging from 100 % to 50 % as measured by the presence of the ¹⁴C isotope.

<4> The LCF-amine curative composition of any of aspects <1> to <3>, where the at least one compound has a % of biomass content ranging from 90 % to 50 % as measured by the presence of the ¹⁴C isotope.

<5> The LCF-amine curative composition of any of aspects <1> to <4>, where the at least one compound is prepared using ¹⁴C containing biobased 1 ,3-propylenediol and/or biobased poly(1 ,3-propylenediol) with MW in the range of 76 g/mol to 3040 g/mol.

<6> The LCF-amine curative composition of any of aspects <1> to <4>, where the at least one compound is prepared using ¹⁴C containing biobased 1 ,3-propylenediol and/or biobased poly(1 ,3-propylenediol) with MW in the range of 76 g/mol to 2280 g/mol.

<7> The LCF-amine curative composition of aspects <5> or <6>, where the biobased 1 ,3-propylenediol is produced by fermentation of biomass.

<8> The LCF-amine curative composition of aspects <5> or <6>, where the biobased poly(1 ,3-propylenediol) is produced by fermentation of biomass and/or polycondensation of biobased 1 ,3-propylenediol.

<9> The LCF-amine curative composition of any of aspects <1> to <8> further comprising at least one amine co-curative made exclusively from fossil fuel based materials having zero ¹⁴C content.

<10> The LCF-amine curative composition of aspect <9> where the least one amine cocurative is an organic diamine or organic triamine.

<11> The LCF-amine curative composition of aspect <8> or <9> where the least one amine co-curative is an aromatic diamine. <12> The LCF-amine curative composition of aspect <11> where the aromatic diamine is selected from the group consisting of

A) a polymethylene-di-p-aminobenzoate with the formula: where X=2-12 carbon alkylene or cycloalkylene groups, where the alkylene and cycloalkylene groups represented by X may be substituted or unsubstituted;

B) a polyethyleneglycol-bis(4-aminobenzoate) with the formula: where n=2-4;

<13> A LCF polyurea composition comprising the reaction of at least one isocyanate and the LCF-amine curative composition of any of aspects <1> to <12>.

<14> The LCF polyurea composition of aspect <13> where the at least one isocyanate is a diisocyanate or polyisocyanate.

<15> The LCF polyurea composition of aspect <14> where the diisocyanate or polyisocyanate is an aliphatic isocyanate, arylaliphatic isocyanate, or aromatic isocyanate selected from hexamethylene diisocyanate, isophorone diisocyanate, phenylene diisocyante, toluene diisocyanate, diphenyl methane diisocyanate isomers, hydrated diphenyl methane diisocyanate isomers and 1 ,5-naphthalene diisocyanate. <16> A method of making a LCF polyurea composition comprising contacting a diisocyanate or polyisocyanate with the LCF-amine curative composition of any of aspects <1> to <12>.

<17> The method of aspect <16> where the diisocyanate or polyisocyanate is an aliphatic isocyanate, arylaliphatic isocyanate, or aromatic isocyanate selected from hexamethylene diisocyanate, isophorone diisocyanate, phenylene diisocyante, toluene diisocyanate, diphenyl methane diisocyanate isomers, hydrated diphenyl methane diisocyanate isomers and 1 ,5-naphthalene diisocyanate.

<18> A method of making a LCF polyurea polymer comprising contacting the biobased amine-curative 1 ,3-propyleneglycolbis(4-aminobenzoate) or poly-(1 ,3- propyleneglycol)bis(4-aminobenzoate) with a diisocyanate or polyisocyanate.

EXAMPLES

[0042] These Examples are provided to demonstrate certain aspects of the invention and shall not limit the scope of the claims appended hereto.

EXAMPLE 1 : Synthesis of Biobased PDO-Oligomer Based Curatives

Procedure for Synthesis of Biobased Curative with Average MW~855:

[0043] A mixture of (300 g, 1 .81 mol) of ethyl p-aminobenzoate, (588.5g, 0.95 mol) of poly (1 ,3 propanediol) with a hydroxyl number of 181 .75 mg KOH/g-sample (MW = 617) and 200g toluene were charged to a 2L round-bottom flask fitted with an overhead stirrer, thermocouple, short path distillation head and a nitrogen sweep. The flask was purged with nitrogen then the mixture was heated to 100°C under vacuum until 50g of toluene was removed to ensure reaction mixture was water free. Vacuum was stopped and replaced with a nitrogen sweep. 1.77g of titanium (IV) butoxide of was added to the flask and then temperature was raised to 165°C and kept at temperature until the concentration of ethyl p-aminobenzoate was less than one weight percent. Residual toluene was then removed under vacuum. The new curative has an average MW = 855 g/mol and a calculated % of biobased carbon of about 69 %. Procedure for Synthesis of Biobased Curative with Average MW 1300:

[0044] A mixture of 200g of ethyl p-aminobenzoate, 676 g of poly (1 ,3 propanediol) with a hydroxyl number of 105.3 mg KOH/g and 200g toluene were charged to a 2L roundbottom flask fitted with an overhead stirrer, thermocouple, short path distillation head and a nitrogen sweep. The flask was purged with nitrogen then the mixture was heated to 100°C under vacuum until 50g of toluene was removed to ensure reaction mixture was water free. Vacuum was stopped and replaced with a nitrogen sweep. 1.75g of titanium IV butoxide was added to the flask and then temperature was raised to 165°C and held there until the ethyl p-aminobenzoate content was less than one weight percent.

Residual toluene was then removed under vacuum. The new curative has an average MW = 1300 g/mol and a calculated % of biobased carbon of about 79 %.

Procedure for Synthesis of Biobased Curative with Average MW 2013:

[0045] A mixture of 125g of ethyl p-aminobenzoate, 709.4g of poly(1 ,3 propanediol) with a hydroxyl number of 63.08 mg KOH/g and 200g toluene were charged to a 2L round-bottom flask fitted with an overhead stirrer, thermocouple, short path distillation head and a nitrogen sweep. The flask was purged with nitrogen then the mixture was heated to 100°C under vacuum until 50g of toluene was removed to ensure reaction mixture was water free. Vacuum was stopped and replaced with a nitrogen sweep. 1.67g of titanium IV butoxide was added to the flask and then temperature was raised to 165°C and held there until ethyl p-aminobenzoate content was less than one weight percent. Residual toluene was then removed under vacuum. The new curative has an average MW = 2013 g/mol and a calculated % of biobased carbon of about 87 %.

EXAMPLE 2: Cast Elastomer

[0046] In cast elastomer, the isocyanate prepolymer and curative components are usually pre-heated, and the streams are mixed hot. The mixed component is pumped through heated lines into molds that are typically heated as well. Specific machinery is available on the market to perform this type of processing. Because raw materials are typically melted and heated, the physical state of the raw materials is no issue to manufacturers.

[0047] Each oligomeric diamine was cured with a carbodiimide-modified 4,4’-MDI (methylene diphenyl diisocyanate) and compared to low-free TDI (toluene diisocyanate) prepolymer of equivalent hardness. Furthermore, for comparison, both PTMEG and PPG-based prepolymers were used to demonstrate inherent differences in performance between PTMEG and PPG at normalized hardness, as these systems are the most well- known ways to make polyurea cast elastomer parts. TDI prepolymers were cured with dimethylthiotoluene diamine. Stoichiometry for all systems were 95% (amine:isocyanate). Prepolymers and oligomeric diamines were melted and pre-heated at 70°C prior to casting. Isocyanate and curatives were mixed at 95% stoichiometry

(amine:isocyanate). Parts made with the TDI prepolymers were cured at 100°C for 16 hours, while parts made with the oligomeric diamines were cured at 70°C for 16 hours. Higher cure temperatures generally produce parts that are harder. However, in general, the mechanical properties for the PPD-based diamine systems are comparable to conventional PTMEG systems and vastly improved over the PPG systems. Abrasion resistance and split tear, in particular, are comparable to PTMEG performance, and this is consistent for all three hardness systems.

Tensile stress at break (psi) M D412C 5230 5860 1460

AST

Abrasion resistance - mass loss (mg)

NBS Abrasion Test 90 100

Tensile story at break (psi) 4670 6200 6200

[0048] For coating and adhesive applications, systems are generally pre-blended and sold. The pre-blended systems are expected to be stable for months so that the end-use customer can use it immediately with as little pre-treatment as possible. The three examples below demonstrate performance in different applications for the oligomeric aromatic diamines that would require some liquid stability.

EXAMPLE 3: Spray Applied Polyurea

[0049] This application relies on pre-made systems that require some phase stability at room temperature (20-25°C). Conventional PTMEG-based amines are solid and are therefore not able to use for this application. Imparting PTMEG on the resin side improves mechanical properties of the spray coating, in particular, abrasion resistance. [0050] Typically formulations consist of an MDI prepolymer with mixtures of 2,4’ and 4,4’ MDI that are based on PPG or PTMEG and are 14-18% NCO. The curative side preferably consists of 2- or 3- functional polyetheramines, which are PPG-based, amine chain extenders, and additives which may help processing, such as UV scavengers, wetting agents, defoamers, and/or adhesion promoters.

[0051] Simplistic formulations were used in the example below to demonstrate the performance based on the oligomeric diamine. Isocyanate side was a PTMEG-based MDI prepolymer at 16% NCO. Curative side consisted of 61 wt% of the 2000 MW amine, 13wt% diethyltoluenediamine, and 26 wt% 4,4’-methylenebis(N-sec-butylaniline). The 2000 MW amines being compared are a PPG-based aliphatic primary diamine (noted as D2000), the PPD-based aromatic diamine (PPD2000) and the PTMEG-based aromatic diamine (P2000). All reactants are pre-heated to 70°C. A and B sides are loaded into a 1 :1 volume cartridge with static mixer on a low-pressure pneumatic gun. Spray pressure at 80-90 psi to make films that are about 0.15 inches in thickness. All films are post-cured at room temperature for 2 weeks prior to conducting physical property tests.

[0052] Because the actual spray is done at elevated temperature, the P2000 can be used to prepare for spray. However, in practice the system must have shelf life phase stability. As P2000 has a relatively high melt point at 36°C, well above standard storage conditions ~25°C, this makes the material unusable even though the film’s final properties are very good. The PPD-2000 is more compatible with the system and will not solidify at room temperature. Although there is a solvent effect when mixing with the chain extenders, we still find that the P2000 drops out of the batch after a few days stored at 23-25°C.

Shore A/D hardness

ASTM D2240

Taber abrasion resistance (mass l

CS-17 wheel/1000g/5000 cycles ²¹

EXAMPLE 4: Conventionally-Applied Coatings (ie. Roller, squeegee)

[0053] The major difference between this system and the spray applied coating is the long potlife. Reactivity between the aromatic amine and isocyante is slow enough that the material can be handmixed and conventionally applied; linear primary polyetheramines conventionally used in spray systems are rarely used in roll-applied cases because their reactivity with isocyanate is too fast. This example demonstrates that a simplistic system composed of curative and small amounts of filler at 80/20 weight ratio. Film is made by curing with carbodiimide-modified 4,4’ liquid MDI (29% NCO), and drawn down at the noted thicknesses. Comparison is against a fully optimized commercial system that contains large levels of filler (talc, calcium carbonate, or barium sulfite, for example) as well as other additions to enhance performance such as drying agents, wetting agents, adhesion promoters, degassers, and/or UV scavengers. All films are drawn down at the specified thickness, then post-cured for 1 day at room temperature. Adhesion test specimens are post-cured at 25°C for 7 days prior to testing. This commercial system is likely also based on PPG, but additional materials are used to enhance performance, whereas the PPD-based system (PPD1000) can meet those performance metrics without any additional help. Similar to the spray coating, PPD1000 may be useful here for its phase stability and viscosity. Systems based on P1000 are more stable than that of P2000 at RT, as the material has a lower melting point that is about 18-20°C.

EXAMPLE 5: Adhesion

[0054] The PPD-based system can also be used as a resin for adhesives. Demonstration of adhesive strength show that the PPD1000 and PPD650 materials produce adhesive strength that is similar to the PTMEG-based system. Like in coatings, adhesive systems are typically pre-blended and are expected to maintain phase stability at ambient conditions over time. Typical adhesive formulations generally contain the base resin (a 2- or 3- functional polyol (preferably polyether) that is between 700 and 3500 MW, chain extender (preferably diol), fillers such as talc, calcium carbonate, or barium sulfate, and additives for processing such as adhesion promoters, rheology modifiers, UV scavengers, wetting agents, drying agents, and defoamers.

[0055] The oligomeric diamine was cured with liquid 4,4’-MDI (29% NCO) at 95% stoichiometry (amine:isocyanate). Mixed resin were applied on pre-cleaned cold-rolled steel coupons with 5 mm bond line. No primer was applied. Samples cured for 1 week under ambient conditions prior to pulling to determine lap shear strength.

[0056] Lap shear strength of the adhesives made with oligomeric diamines made based on PPD are comparable to those made with PTMEG and are comparable to a fully

20

SUBSTITUTE SHEET (RULE 26) formulated system. These results are obtained without any additional additives to the system that can promote adhesion (ie. aminosilanes for adhesion promotion, silicone surfactants for wetting enhancement).

EXAMPLE 6: Environmental Benefit & Reduction in CO₂ Emissions

[0057] Poly(1 ,3-propyleneglycol) with a hydroxyl number of 105.3 mg KOH/g (MW ~ 1063 g/mol) is used as a sustainable alternative to petro-chemical based poly- (tetramethylene ether)-glycol (PTMEG). A mixture of 200g of ethyl p-aminobenzoate, 676 g of poly (1 ,3 propanediol) with a hydroxyl number of 105.3 mg KOH/g and 200g toluene were charged to a 2L round-bottom flask fitted with an overhead stirrer, thermocouple, short path distillation head and a nitrogen sweep. The flask was purged with nitrogen then the mixture was heated to 100°C under vacuum until 50g of toluene was removed to ensure reaction mixture was water free. Vacuum was stopped and replaced with a nitrogen sweep. 1 ,75g of titanium IV butoxide was added to the flask and then temperature was raised to 165°C and held there until ethyl p-aminobenzoate content was less than one weight percent. Residual toluene was then removed under vacuum. The new curative has an average MW = 1300 g/mol and a calculated % of biobased carbon of about 79 %.

[0058] When PTMEG with MW ~1000 g/mol is replaced in a 1 :1 drop-in with biobased poly(1 ,3-propyleneglycol) with MW ~ 1000 g/mol the carbon footprint can be reduced by more than 50%. Thus, while PTMEG MW = 1000 would result in the release of 9.61 Kg CO₂/equivalent of amine-curative, the biobased poly(1 ,3-propyleneglycol) with MW ~ 1000 g/mol would result in the release of 4.67 Kg CO₂/equivalent of amine curative bringing a 50% carbon emissions reduction.

EXAMPLE 7: MALDI and GPC Analysis of New Curatives (Prophetic)

[0059] MALDI and GPC analysis of the new composition also discloses a unique distribution of isomers as denoted by the ranges of “n” in the general formula such that the curative remains liquid, or formation of solids does not occur for a long period of time, resulting essentially in liquid amine curatives without the need of providing heat for melting resulting in improved processing.

Claims

1. A LCF-amine curative composition comprising at least one compound with the formula: where n = 1-40, having a % of biomass content ranging from 100 % to 10 % as measured by the presence of the ¹⁴C isotope.

2. The LCF-amine curative composition of claim 1 , where the at least one compound has n = 1-30.

3. The LCF-amine curative composition of claim 1 or 2, where the at least one compound has a % of biomass content ranging from 100 % to 50 % as measured by the presence of the ¹⁴C isotope.

4. The LCF-amine curative composition of any of claims 1 -3, where the at least one compound has a % of biomass content ranging from 90 % to 50 % as measured by the presence of the ¹⁴C isotope.

5. The LCF-amine curative composition of any of claims 1 -4, where the at least one compound is prepared using ¹⁴C containing biobased 1 ,3-propylenediol and/or biobased poly(1 ,3-propylenediol) with MW in the range of 76 g/mol to 3040 g/mol.

6. The LCF-amine curative composition of any of claims 1 -4, where the at least one compound is prepared using ¹⁴C containing biobased 1 ,3-propylenediol and/or biobased poly(1 ,3-propylenediol) with MW in the range of 76 g/mol to 2280 g/mol.

7. The LCF-amine curative composition of claim 5 or 6, where the biobased 1 ,3- propylenediol is produced by fermentation of biomass.

8. The LCF-amine curative composition of claim 5 or 6, where the biobased poly(1 ,3-propylenediol) is produced by fermentation of biomass and/or polycondensation of biobased 1 ,3-propylenediol.

9. The LCF-amine curative composition of any of claims 1 -8 further comprising at least one amine co-curative made exclusively from fossil fuel based materials having zero ¹⁴C content.

10. The LCF-amine curative composition of claim 9 where the least one amine co- curative is an organic diamine or organic triamine.

11 . The LCF-amine curative composition of claim 8 or 9 where the least one amine co-curative is an aromatic diamine.

12. The LCF-amine curative composition of claim 11 where the aromatic diamine is selected from the group consisting of

E) a polymethylene-di-p-aminobenzoate with the formula: where X=2-12 carbon alkylene or cycloalkylene groups, where the alkylene and cycloalkylene groups represented by X may be substituted or unsubstituted;

F) a polyethyleneglycol-bis(4-aminobenzoate) with the formula: where n=2-4;

G) a polydimethylsiloxane-bis(4-aminobenzoate) with the formula: where n=2-4; and

H) a polytetramethyleneetherglycol-di-p-aminobenzoate with the formula: where n=1-40.

13. A LCF polyurea composition comprising the reaction of at least one isocyanate and the LCF-amine curative composition of any of claims 1-12.

14. The LCF polyurea composition of claim 13 where the at least one isocyanate is a diisocyanate or polyisocyanate.

15. The LCF polyurea composition of claim 14 where the diisocyanate or polyisocyanate is an aliphatic isocyanate, arylaliphatic isocyanate, or aromatic isocyanate selected from hexamethylene diisocyanate, isophorone diisocyanate, phenylene diisocyante, toluene diisocyanate, diphenyl methane diisocyanate isomers, hydrated diphenyl methane diisocyanate isomers and 1 ,5-naphthalene diisocyanate.

16. A method of making a LCF polyurea composition comprising contacting a diisocyanate or polyisocyanate with the LCF-amine curative composition of any of claims 1-12.

17. The method of claim 16 where the diisocyanate or polyisocyanate is an aliphatic isocyanate, arylaliphatic isocyanate, or aromatic isocyanate selected from hexamethylene diisocyanate, isophorone diisocyanate, phenylene diisocyante, toluene diisocyanate, diphenyl methane diisocyanate isomers, hydrated diphenyl methane diisocyanate isomers and 1 ,5-naphthalene diisocyanate.

18. A method of making a LCF polyurea polymer comprising contacting the biobased amine-curative 1 ,3-propyleneglycolbis(4-aminobenzoate) or poly-(1 ,3- propyleneglycol)bis(4-aminobenzoate) with a diisocyanate or polyisocyanate.