Epoxy resin

Abstract

The name of the invention is epoxy resin. The present disclosure relates to epoxide-containing compounds comprising three benzene units linked by a bridging group. The present disclosure also relates to the production of curable epoxy resin formulations comprising the epoxide-containing compounds, as well as the possible incorporation thereof in composite materials, such as fiber-reinforced composite materials. Also disclosed are possible methods of formulating compounds including epoxide-containing compounds as described herein.

Description

[0001] This application is a divisional application of a patent application with an application date of July 20, 2017, application number 2017800501327, and name “Epoxy Resin”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 366,443, filed on July 25, 2016, and Australian Provisional Patent Application No. 2016904019, filed on October 4, 2016, the contents of which are incorporated herein by reference. Technical Field

[0004] Disclosed herein are epoxide-containing compounds comprising three benzene units connected by a bridging atom; the production of curable epoxy resin formulations comprising the epoxide-containing compounds; and the possible incorporation of the compounds into composite materials. Background Art

[0005] For fiber-reinforced composites, the efficiency of load transfer between the fibers and the surrounding matrix at the microscale directly affects the overall mechanical properties of the composite at the continuum level. The matrix region (sometimes referred to as the "interphase" region) that is significantly affected by the presence of fibers is the interfacial region of the matrix directly surrounding the fibers. In composites, it is this interphase region that experiences high shear strains due to the mismatch in elastic stiffness between the fibers and the surrounding matrix.

[0006] Although various resin matrix preparations have been developed to maximize the twisting capacity of polymer resins, the preparations that show higher performance potential still have limitations, such as limited fluid resistance and pre-impregnated composite materials (prepregs) processing characteristics that are lower than expectation, such as tackiness and / or prepreg processing lifespan deficiency. These problems can be partially solved by the chemical structure (chemistry) of the overall polymer resin that forms matrix through modification. However, these modifications need to develop special monomers or additives, which may increase production costs. And, although these special preparations and additives can improve the fluid resistance of matrix resins, they may reduce other properties of composite materials.

[0007] Epoxy may be deformed by expansion and / or distortion. Materials that primarily respond to distortion rather than expansion tend to show high strength and improved performance compared to materials that rely on expansion. Herein, the inventors have conducted extensive research and development to identify alternative types of epoxy resins that exhibit enhanced distortion while exhibiting appropriate matrix modulus, glass transition temperature (Tg), and environmental resistance properties.

[0008] Epoxy resin is a versatile material that can be combined with fibers to produce a variety of composite materials, including a range of prepreg compositions.

[0009] For composite materials including epoxy resin and fibers, the angle of the fibers affects the distribution of distortion and expansion deformation. Therefore, the angle of the incorporated fibers is selected so as to absorb mechanical energy and create an environment of distortion rather than expansion deformation. As the angle approaches parallel to the main load direction, the mode of deformation decreases in the form of expansion deformation and increases in the form of distortion deformation. Finding the optimal angle of the fibers allows increasing the load carried by the fibers in these composites.

[0010] While the expansion deformation characteristics are generally similar among various epoxies, the intramolecular torsional conformational arrangements within the components of the epoxide mean that the distortion deformation properties can differ significantly for various epoxy resins.

[0011] Because distortion is often preferred, the challenge is to identify materials that possess the best distortion properties while balancing them with material characteristics such as Tg and stiffness.

[0012] Therefore, there is a need to develop and identify alternative types of epoxy resins that display enhanced twisting behavior while maintaining high performance properties. The twisted epoxy resin can then be combined with fibers to produce a composite that absorbs mechanical energy and dissipates that energy as heat, preventing potential expansion cracks and allowing the load carried by the fibers to be increased.

[0013] Any discussion of documents, acts, materials, devices, articles or the like included in this specification should not be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application. Summary of the invention

[0014] In one aspect, disclosed herein are compounds of Formula 1 or Formula 2:

[0015]

[0016] in:

[0017] Each X 1 are identical and are selected from O and C(O);

[0018] Each X 2 are identical and are selected from C(O); and

[0019] Each R 1 is hydrogen and each R 2 is selected from epoxide groups, or each R 2 is hydrogen and each R 1Selected from epoxide groups.

[0020] In one example, the epoxide group is selected from:

[0021] In another example:

[0022] (a) When X 1 When is O, the epoxide group is

[0023] (b) When X 1 When C(O), the epoxide group is and

[0024] (c) When X 2 When it is C(O), either:

[0025] (i)R 2 It is H and R 1 yes or

[0026] (ii) R 1 It is H and R 2 yes

[0027] In another aspect, disclosed herein is a curable epoxy resin formulation comprising an epoxide-containing compound as defined herein and a curing agent.

[0028] In another aspect, disclosed herein is a curable epoxy resin formulation comprising an epoxy resin and a curing agent, wherein:

[0029] The epoxy resin includes a compound of Formula 3:

[0030]

[0031] in

[0032] Each X is the same and is selected from O, CH2 and C(O);

[0033] Each R is the same and is an epoxide group; and

[0034] The curing agent includes a diamine curing agent of formula 4:

[0035]

[0036] wherein each Y is the same and is selected from O, CH2 and C(O).

[0037] In one example, the epoxide group is selected from:

[0038] In another example, each R is the same and is an epoxide group selected from: And optionally, when R is When X is CH2, the CH2 groups are in the meta position relative to each other.

[0039] In another aspect, disclosed herein is an impregnated fiber reinforced material comprising fibers impregnated with a curable epoxy resin formulation as defined herein.

[0040] In another aspect, disclosed herein is a composite material comprising a fibrous material in a matrix of a cured epoxy resin, wherein the cured epoxy resin is formed from a curable epoxy resin formulation as defined herein.

[0041] In another aspect, disclosed herein is forming an impregnated fiber reinforced material, the method comprising the steps of;

[0042] a) Provide:

[0043] (i) a curable epoxy resin formulation as defined herein; and

[0044] (ii) fibrous materials; and

[0045] b) combining the resin formulation of step (a)(i) with the fibrous material of step (a)(ii) and subjecting the materials to elevated temperatures,

[0046] This elevated temperature enables curing to form the impregnated fiber reinforced material.

[0047] In another aspect, disclosed herein is the use of a compound as defined herein as a curable epoxy resin or in the preparation of a curable epoxy resin formulation.

[0048] In another aspect, disclosed herein is a method for preparing a compound of Formula 8, comprising the steps of:

[0049] i) reacting a compound of formula 5 with a compound of formula 6 in the presence of a catalyst to form a compound of formula 7, wherein P is a protecting group, M is a metal and LG is a leaving group:

[0050]

[0051] ii) further reacting the compound of formula 7 with an acid catalyst to form a compound of formula 8;

[0052]

[0053] In another aspect, disclosed herein is a method of preparing a compound of formula 10, comprising the steps of: reacting a compound of formula 8 with a halogenated epoxy compound of formula 9 to form a compound of formula 10;

[0054]

[0055] In one example, the compound of formula 8 is prepared by a method according to aspects of the above paragraphs. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] While it will be appreciated that various examples of the present disclosure may be utilized, below, we describe a number of examples with reference to the following figures;

[0057] Figure 1 -N,N,N,N-tetraglycidyl 1,4-bis(4-aminophenoxy)benzene (144-TGAPB) 1 H(image a)) and 13 C (Image b)) NMR spectrum.

[0058] Figure 2 - HPLC showing the resolution times of components in the synthesis of N,N,N,N-tetraglycidyl 1,4-bis(4-aminophenoxy)benzene (144-TGAPB).

[0059] Figure 3 -N,N,N,N-tetraglycidyl 1,3-bis(4-aminophenoxy)benzene (134-TGAPB) 1 H(image a)) and 13 C (Image b)) NMR spectrum.

[0060] Figure 4 - HPLC showing the resolution times of components in the synthesis of N,N,N,N-tetraglycidyl 1,3-bis(4-aminophenoxy)benzene (134-TGAPB).

[0061] Figure 5 -N,N,N,N-tetraglycidyl 1,3-bis(3-aminophenoxy)benzene (133-TGAPB) 1 H(image a)) and 13 C (Image b)) NMR spectrum.

[0062] Figure 6 - HPLC showing the resolution times of components in the synthesis of N,N,N,N-tetraglycidyl 1,3-bis(3-aminophenoxy)benzene (133-TGAPB).

[0063] Figure 7-1 ,3-bis(3-glycidyloxyphenoxy)benzene 1 H(image a)) and 13 C (Image b)) NMR spectrum.

[0064] Figure 8 - HPLC showing the resolution times of components in the synthesis of 1,3-bis(3-glycidyloxyphenoxy)benzene.

[0065] Figure 9-1 ,4-bis(4-glycidyloxyphenoxy)benzene 1 H(image a)) and 13 C (Image b)) NMR spectrum.

[0066] Fig.10 - HPLC showing the resolution times of components in the synthesis of 1,4-bis(4-glycidyloxyphenoxy)benzene.

[0067] Fig.11 - Differential scanning chromatography of purified 1,4-bis(4-glycidyloxyphenoxy)benzene.

[0068] Fig.12 - High performance liquid chromatogram showing the resolution times of isomeric products produced during the synthesis of bis(4-hydroxyphenyl)-meta-xylene, wherein: a) indicates phenol; b) indicates the 4,4 isomer; c) indicates the 2,4 isomer; d) indicates the 2,2 isomer; and e) indicates oligomers.

[0069] Figure 13-2 -Hydroxyphenyl-m-xylene 1 H NMR spectrum, where: a) represents two OH groups; b) represents twelve aromatic CH groups; c) represents four aliphatic CH groups; and d) shows dimethyl sulfoxide (DMSO).

[0070] Fig.14 - High performance liquid chromatogram showing the resolution times of isomeric products produced during the synthesis of bis(4-hydroxyphenyl)-p-xylene, wherein: a) indicates phenol; b) indicates the 4,4 isomer; c) indicates the 2,4 isomer; d) indicates the 2,2 isomer; and e) indicates oligomers.

[0071] Figure 15-2 -Hydroxyphenyl-p-xylene 1 H NMR spectrum, where: a) represents two OH groups; b) represents twelve aromatic CH groups; c) represents four aliphatic CH groups; and d) shows dimethyl sulfoxide (DMSO).

[0072] Fig.16 - Curves of the respective concentrations of different isomers, phenol and oligomer species during the synthesis of bis(hydroxyphenyl)-p-xylene.

[0073] Fig.17- Dynamic mechanical thermal analysis (DMTA) spectra of diglycidyl ether of bisphenol A (BisA), diglycidyl ether of bisphenol F (BisF) and 1,4-di(4-glycidyletherphenoxy)benzene (144BGOPB) networks cured with a) 1,3-di(3-aminobenzoyl)benzene (133BABB), b) 1,3-di(4-aminobenzoyl)benzene (134BABB) and c) 1,4-di(4-aminobenzoyl)benzene (144BABB).

[0074] Fig.18 - a) Flexural modulus, b) strength and c) displacement at failure of BisA, BisF and 144BGOPB networks cured with 133BABB, 134BABB and 144BABB.

[0075] Fig.19 - Methyl ethyl ketone (MEK) incorporation as a function of time for 133, 134 and 144 BABB networks cured with a) BisA, b) BisF and c) 144 BGOPB.

[0076] Fig. 20 - DMTA tan delta traces showing the change in Tg of different epoxy resins after curing with a) 44DDS and b) MDA. Curing was 150°C for 12 hours and post curing at 177°C for 3 hours.

[0077] Fig.21 - DMTA spectra of BGOPpX / 44DDS-cured networks after curing at different post-cure temperatures.

[0078] Fig. 22 – Modulus curves for post-cured systems incorporating 44DDS and MDA hardeners.

[0079] Figure 23-4 4. Curves of a) yield strain and b) yield stress for the post-cured system of both DDS and MDA hardeners.

[0080] Fig.24 - Curves of solvent ingress as a function of time for a) 44DDS and b) MDA cured networks with MEK at room temperature.

[0081] Fig.25 - Comparison of tan delta spectra of 144-BGOPB and 133-BGOPB epoxies with BisF cured with 44DDS and 33DDS.

[0082] Fig.26- Original compressive strength versus strain curves of a) 144-BGOPB and 133-BGOPB cured networks compared to b) BisF cured with 44DDS and 33DDS. DETAILED DESCRIPTION

[0083] In the present disclosure, curable epoxy resin formulations have been developed that include compounds comprising three aromatic rings connected via ether, carbonyl or methylene groups and terminated by two or four epoxide groups. The aromatic structure provides strength, and the ether, carbonyl or methylene bridging groups allow twisting to dissipate any mechanical energy and increase the twisting ability of the cured epoxy resin. In addition, the epoxide groups incorporated into the compounds defined herein enable crosslinking to a polymer network structure.

[0084] As described herein, curable epoxy resins and formulations thereof have been developed for the possible production of composite materials.It is an object of the present disclosure to develop curable epoxy resin formulations with increased distortion properties to improve the performance of composite materials.

[0085] The compounds, composite materials, methods and uses defined herein will now be described more fully hereinafter.

[0086] With respect to the definitions provided herein, unless otherwise stated or implied from the context, the defined terms and phrases include the meanings provided. Unless otherwise explicitly stated or obvious from the context, the following terms and phrases do not exclude the meanings that a person skilled in the relevant art would have acquired for the term or phrase. These definitions are provided to aid in describing specific examples and are not intended to limit the claims, as the scope is limited only by the claims. In addition, unless the context requires otherwise, singular terms shall include the plural and plural terms shall include the singular.

[0087] Throughout the specification, various aspects and components of the present invention can be presented in range format. For convenience, range format is included, which should not be interpreted as an inflexible limitation on the scope of the present disclosure. Therefore, unless specifically noted, it should be considered that the description of the range specifically discloses all possible sub-ranges and each numerical value within the range. For example, it should be considered that the description of a range such as from 1 to 5 specifically discloses a sub-range, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 5, from 3 to 5, etc., and single digits and partial digits (unless integers are required) within the range, such as 1, 2, 3, 4, 5, 5.5 and 6. This applies to any width of the disclosed range. If a specific value is required, these will be indicated in the specification.

[0088] the term

[0089] Throughout the specification, the words “comprise”, “comprises”, “comprising” will be understood to imply the inclusion of stated elements, integers or steps, or groups of elements, integers or steps, but not the exclusion of any other elements, integers or steps, or groups of elements, integers or steps.

[0090] Throughout the specification, the term "consisting essentially of is intended to exclude elements that may substantially affect the properties of the claimed composition, although elements that do not substantially affect the properties may be included.

[0091] Epoxide-containing compounds

[0092] Disclosed herein are compounds of Formula 1:

[0093]

[0094] in:

[0095] Each X 1 are the same and are selected from O, CH2 and C(O); and

[0096] Each R 1 is hydrogen and each R 2 is selected from epoxide groups, or each R 2 is hydrogen and each R 1 Selected from epoxide groups.

[0097] Also disclosed herein are compounds of Formula 2:

[0098]

[0099] in:

[0100] Each X 2 are the same and are selected from O, CH2 and C(O); and

[0101] Each R 1 is hydrogen and each R 2 is selected from epoxide groups, or each R 2 is hydrogen and each R 1 Selected from epoxide groups.

[0102] Also disclosed herein are compounds of Formula 1a:

[0103]

[0104] in:

[0105] Each X 1 are the same and are selected from O, CH2 and C(O); and

[0106] Each R 2 Selected from epoxide groups.

[0107] Also disclosed herein are compounds of Formula 1b:

[0108]

[0109] in:

[0110] Each X 1 are the same and are selected from O, CH2 and C(O); and

[0111] Each R 1 Selected from epoxide groups.

[0112] Also disclosed herein are compounds of Formula 2a:

[0113]

[0114] in:

[0115] Each X 2 are the same and are selected from O, CH2 and C(O); and

[0116] Each R 1 Selected from epoxide groups.

[0117] Disclosed herein are compounds of Formula 2b:

[0118]

[0119] in:

[0120] Each X 2 are the same and are selected from O, CH2 and C(O); and

[0121] Each R 2 Selected from epoxide groups.

[0122] Substituent X 1 , X 2 , R 1 and R 2

[0123] In any compound of Formula 1, 1a or 1b, X 1 It can be O, CH2 or C(O).

[0124] In one example, X 1 is O. In another example, X 1 In another example, X 1 It is CH2.

[0125] In any compound of Formula 2, 2a or 2b, X 2 It can be O, CH2 or C(O).

[0126] In one example, X 2 is O. In another example, X 2 In another example, X 2 It is CH2.

[0127] In another example, each X 1 are the same and are selected from O and C(O); and each X 2 are identical and are selected from C(O).

[0128] In any compound of Formula 1, 1b, 2 or 2a, R 1 It can be hydrogen or an epoxide group.

[0129] In any compound of Formula 1, 1a, 2 or 2b, R 2 It can be hydrogen or an epoxide group.

[0130] In one example, each R 1 is hydrogen and each R 2 Selected from epoxide groups.

[0131] In one example, each R 2 is hydrogen and each R 1 Selected from epoxide groups.

[0132] Epoxide group

[0133] For compounds of Formula 1, 1a or 1b, the epoxide group may be selected from:

[0134]

[0135] For compounds of Formula 2, 2a or 2b, the epoxide group may be selected from:

[0136]

[0137] In one example, R 1 yes

[0138]

[0139] In another example, R 1 yes

[0140]

[0141] In one example, R 2 yes

[0142]

[0143] In yet another example, R 2 yes

[0144]

[0145] In one example, when X 1 When is O, the epoxide group is In another example, when X 1 When is O, the epoxide group is

[0146] In one example, when X 2 When is O, the epoxide group is In another example, when X 2 When is O, the epoxide group is

[0147] In one example, when X 1 When CH2, the epoxide group is In another example, when X 1 When CH2, the epoxide group is

[0148] In one example, when X 2 When CH2, the epoxide group is In another example, when X 2 When CH2, the epoxide group is

[0149] In one example, when X 1 When C(O), the epoxide group is In another example, when X 1 When C(O), the epoxide group is

[0150] In one example, when X 2 When C(O), the epoxide group is In another example, when X 2 When C(O), the epoxide group is

[0151] In an example, the compound of Formula 1 or Formula 2 may be selected from any one of the following:

[0152]

[0153] In an example, the compound of Formula 1 or Formula 2 may be selected from any one of the following:

[0154]

[0155] In an example, the compound of Formula 1 or Formula 2 may be selected from any one of the following:

[0156]

[0157]

[0158] In an example, the compound of Formula 1 or Formula 2 may be selected from any one of the following:

[0159]

[0160]

[0161] In an example, the compound of Formula 1 or Formula 2 may be selected from any one of the following:

[0162]

[0163] In an example, the compound of Formula 1 or Formula 2 may be selected from any one of the following:

[0164]

[0165]

[0166] Curable epoxy resin formulations

[0167] Disclosed herein are curable epoxy resin formulations including a compound of Formula 1, 1a, 1b, 2, 2a, or 2b, or mixtures thereof.

[0168] Disclosed herein are curable epoxy resin formulations comprising a compound of Formula 1, 1a, 1b, 2, 2a, or 2b, or a mixture thereof, and a curing agent.

[0169] Also disclosed herein are curable epoxy resin formulations consisting of or consisting essentially of a compound of any of Formulas 1, 1a, 1b, 2, 2a, or 2b, or mixtures thereof, and a curing agent.

[0170] In one example, the curable epoxy resin formulation includes the compound of Formula 1.

[0171] In one example, the curable epoxy resin formulation includes a compound of Formula 2.

[0172] Disclosed herein is a curable epoxy resin formulation comprising an epoxy resin and a curing agent, wherein:

[0173] Epoxy resins include compounds of Formula 3:

[0174]

[0175] in:

[0176] Each X is the same and is selected from O, CH2 and C(O); and

[0177] Each R is the same and is an epoxide group.

[0178] Disclosed herein is a curable epoxy resin consisting essentially of an epoxy resin and a curing agent, wherein:

[0179] Epoxy resins include compounds of Formula 3:

[0180]

[0181] in:

[0182] Each X is the same and is selected from O, CH2 and C(O); and

[0183] Each R is the same and is an epoxide group.

[0184] Disclosed herein is a curable epoxy resin formulation comprising an epoxy resin and a curing agent, wherein:

[0185] Epoxy resins include compounds of Formula 3:

[0186]

[0187] in:

[0188] Each X is the same and is selected from O, CH2 and C(O);

[0189] Each R is the same and is an epoxide group; and

[0190] The curing agent includes a diamine curing agent of Formula 4:

[0191]

[0192] wherein each Y is the same and is selected from O, CH2 and C(O).

[0193] Disclosed herein are curable epoxy resin formulations consisting of or consisting essentially of an epoxy resin and a curing agent, wherein:

[0194] Epoxy resins include compounds of Formula 3:

[0195]

[0196] in:

[0197] Each X is the same and is selected from O, CH2 and C(O);

[0198] Each R is the same and is an epoxide group; and

[0199] The curing agent includes a diamine curing agent of Formula 4:

[0200]

[0201]

[0202] wherein each Y is the same and is selected from O, CH2 and C(O).

[0203] In Formula 3, two X substituents can be connected to the central phenyl ring with ortho, meta or para positions with respect to each other. In one example, two X substituents are located at 1 and 2 (ortho substitution) on the central phenyl ring. In another example, two X substituents are located at 1 and 3 (meta substitution) on the central phenyl ring. In still another example, two X substituents are located at 1 and 4 (para substitution) on the central phenyl ring.

[0204] Herein, the compound of Formula 3 may be a compound of Formula 3a:

[0205]

[0206] in:

[0207] Each X is the same and is selected from O, CH2 and C(O); and

[0208] Each R is the same and is an epoxide group.

[0209] Herein, the compound of Formula 3 may be a compound of Formula 3a-i:

[0210]

[0211] in:

[0212] Each X is the same and is selected from O, CH2 and C(O); and

[0213] Each R is the same and is an epoxide group.

[0214] Herein, the compound of Formula 3 may be a compound of Formula 3a-ii:

[0215]

[0216] in:

[0217] Each X is the same and is selected from O, CH2 and C(O); and

[0218] Each R is the same and is an epoxide group.

[0219] Herein, the compound of Formula 3 may be a compound of Formula 3b:

[0220]

[0221] in:

[0222] Each X is the same and is selected from O, CH2 and C(O); and

[0223] Each R is the same and is an epoxide group.

[0224] Herein, the compound of Formula 3 may be a compound of Formula 3b-i:

[0225]

[0226] in:

[0227] Each X is the same and is selected from O, CH2 and C(O); and

[0228] Each R is the same and is an epoxide group.

[0229] Herein, the compound of Formula 3 may be a compound of Formula 3b-ii:

[0230]

[0231] in:

[0232] Each X is the same and is selected from O, CH2 and C(O); and

[0233] Each R is the same and is an epoxide group.

[0234] In any of the above examples of curable epoxy resin formulations, the epoxy resin can consist of, or can consist essentially of, a compound of Formula 3, or any example thereof described herein, and optionally a curing agent.

[0235] In another example of any of the above curable epoxy resin formulations, the curing agent present in the curable epoxy resin formulation can consist of, or consist essentially of, a diamine curing agent of Formula 4, or any example thereof described herein.

[0236] The compound of formula 3 may be selected from compounds of formula 1 as defined herein. Alternatively, the compound of formula 3 may be selected from compounds of formula 1a or formula 1b as defined herein.

[0237] The compound of formula 3 may be selected from the compounds of formula 2 as defined herein. Alternatively, the compound of formula 3 may be selected from the compounds of formula 2a or formula 2b as defined herein.

[0238] The compound of formula 3 may be selected from the compounds of formula 3a as defined herein. Alternatively, the compound of formula 3 may be selected from the compounds of formula 3a-i or formula 3a-ii as defined herein.

[0239] The compound of formula 3 may be selected from the compounds of formula 3b as defined herein. Alternatively, the compound of formula 3 may be selected from the compounds of formula 3b-i or formula 3b-ii as defined herein.

[0240] Substituents R and X

[0241] For compounds of Formula 3, X may be O, CH2 or C(O).

[0242] In one example, X is O. In another example, X is C(O). In still another example, X is CH2.

[0243] In the compound of Formula 3, each R group may be an epoxide group selected from:

[0244]

[0245] In one embodiment, the substituent R in the compound of formula 3 is

[0246]

[0247] In one embodiment, the substituent R in the compound of formula 3 is

[0248]

[0249] In one example, when X is O, the substituent R is In another example, when X is O, the substituent R is

[0250] In one example, when X is CH2, the substituent R is In another example, when X is CH2, the substituent R is

[0251] In one example, when X is C(O), the substituent R is In another example, when X is C(O), the substituent R is

[0252] In one example, the compound of Formula 3 can be selected from any one of the following:

[0253]

[0254] In one example, the compound of Formula 3 can be selected from any one of the following:

[0255]

[0256]

[0257] In one example, the compound of Formula 3 can be selected from any one of the following:

[0258]

[0259] In one example, the compound of Formula 3 can be selected from any one of the following:

[0260]

[0261] In one example, the compound of Formula 3 can be selected from any one of the following:

[0262]

[0263]

[0264] In one example, the compound of Formula 3 can be selected from any one of the following:

[0265]

[0266]

[0267] Curing agent

[0268] Curing agents such as amines, imidazoles, anhydrides, phenols, and thiols are known to those skilled in the art and can be used in the compositions described herein.

[0269] Herein, the ratio of the curing agent to the compound of Formula 1, Formula 2, or Formula 3 can vary from a balanced stoichiometry of about 1.0:1.0 to a stoichiometry of about 0.6:1.0. For example, the ratio of the curing agent to the compound of Formula 1, Formula 2, or Formula 3 can be about 1.0:1.0, about 0.95:1.0, about 0.90:1.0, about 0.85:1.0, about 0.75:1.0, about 0.70:1.0, about 0.65:1.0, or about 0.6:1.0. In one example, the ratio is 0.7:1.0.

[0270] For the curable epoxy resin formulations disclosed herein, the curing agent may be an amine.

[0271] In one example, the curing agent is an aliphatic amine, a cycloaliphatic amine, or an aromatic amine. Examples of possible amine curing agents include, but are not limited to: N-aminoethylpiperazine, alkylenediamine, isophoronediamine, meta-xylene diamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenyl sulfone, 3,3'-sulfodiphenylamine, 4,4'-sulfodiphenylamine, 4,4'-diphenylaminomethane, 4,4'-oxydinaniline, 4,4'-methylenebis(2-ethylaniline), 3,3'-((2,2-dimethylpropane-1,3-diyl)bis(oxy))diphenylamine, 4,4'-(1,4-phenylenebis-(propane-2,2-diyl))diphenylamine, 3-(4-(4-aminobenzyl)-benzyl)aniline, 4,4'-(1,4-phenylenebis(propane-2,2-diyl))bis(2,6-dimethylaniline), 4,4'-(1,4-phenylenebis(oxy))-diphenylamine, 3,3'-((propane-2,2-diylbis-(4,1-phenylene))bis(oxy))-diphenylamine, 4, 4'-methylenebis(cyclohexyl-1-amine), 4,4'-sulfur diphenylamine, 3,3'-((sulfonyldi(4,1-phenylene))di(oxy))diphenylamine, 4,4'-(1,4-phenylenedi-sulfonyl)diphenylamine, 4,4'-(pentane-1,5-diyldi-(oxy))diphenylamine, 4,4'-([1,1'-diphenyl]-4,4'-diyldi(oxy))diphenylamine, 4,4'-(1,3-phenylenedi- -(propane-2,2-diyl))bis(2,6-diisopropylaniline), 4,4'-(1,3-phenylenebis-(propane-2,2-diyl))diphenylamine, 4,4'-((sulfonylbis(4,1-phenylene))bis(oxy))diphenylamine, 4,4'-((propane-2,2-diylbis(4,1-phenylene))bis(oxy))diphenylamine, 4,4'-disulfanediyldiphenylamine, and 4,4'-disulfanediyldiphenylamine.

[0272] In one example, the curing agent is an amine, wherein the ratio of the amine to the compound of Formula 1, Formula 2, or Formula 3 can be varied from a balanced stoichiometry of about 1.0:1.0 to a stoichiometry of about 0.6:1.0. For example, the ratio of the amine curing agent to the compound of Formula 1, Formula 2, or Formula 3 can be about 1.0:1.0, about 0.95:1.0, about 0.90:1.0, about 0.85:1.0, about 0.75:1.0, about 0.70:1.0, about 0.65:1.0, or about 0.6:1.0. In one example, the ratio is 0.7:1.0.

[0273] The curing agent may be a diamine curing agent of formula 4:

[0274]

[0275] wherein each Y is the same and is selected from O, CH2 and C(O).

[0276] In formula 4, two Y substituents can be connected to the central phenyl ring with ortho, meta or para positions with respect to each other. In one example, two Y substituents are located at 1 and 2 (ortho substitution) on the central phenyl ring. In another example, two Y substituents are located at 1 and 3 (meta substitution) on the central phenyl ring. In still another example, two Y substituents are located at 1 and 4 (para substitution) on the central phenyl ring.

[0277] The curing agent may be a diamine curing agent of formula 4a:

[0278]

[0279] wherein each Y is the same and is selected from O, CH2 and C(O).

[0280] The curing agent may be a diamine curing agent of formula 4b:

[0281]

[0282] wherein each Y is the same and is selected from O, CH2 and C(O).

[0283] The curing agent may be a diamine curing agent of formula 4c:

[0284]

[0285] wherein each Y is the same and is selected from O, CH2 and C(O).

[0286] The curing agent may be a diamine curing agent of formula 4d:

[0287]

[0288] wherein each Y is the same and is selected from O, CH2 and C(O).

[0289] For compounds of any of Formula 4, 4a, 4b, 4c or 4d, Y may be O, CH2 or C(O).

[0290] In one example, Y is O. In another example, Y is C(O). In another example, Y is CH2.

[0291] In an example, the example of Formula 4 can be selected from any one of the following:

[0292]

[0293]

[0294] In an example, the example of Formula 4 can be selected from any one of the following:

[0295]

[0296]

[0297] In an example, the example of Formula 4 can be selected from any one of the following:

[0298]

[0299] Herein, the ratio of the curing agent of Formula 4 to the compound of Formula 1, Formula 2 or Formula 3 can be varied from a balanced stoichiometry of about 1.0:1.0 to a stoichiometry of about 0.6:1.0. For example, the ratio of the compound of Formula 4 to the compound of Formula 1, Formula 2 or Formula 3 can be about 1.0:1.0, about 0.95:1.0, about 0.90:1.0, about 0.85:1.0, about 0.75:1.0, about 0.70:1.0, about 0.65:1.0, or about 0.6:1.0. In one example, the ratio is 0.7:1.0.

[0300] As described herein, the curable epoxy resin formulation may further include one or more additives or one or more additional epoxy resins known in the art. These include: diglycidyl ethers of bisphenol A, F epoxy resins, triglycidyl p-aminophenol epoxy resins, and tetraglycidylamine epoxy resins. For example, the curable epoxy resin formulation may further include 4,4′-methylene diphenol (bisphenol F). Bisphenol F can be added as a liquid carrier for making prepreg materials.

[0301] Examples of additives include, but are not limited to, functional additives that can be added to the curable epoxy resin formulation to impart properties that affect: the mechanical, rheological, electrical, optical, chemical, flame retardant and / or thermal properties of the cured or uncured epoxy resin formulation. Examples of additives include, but are not limited to: flame retardants, ultraviolet (UV) stabilizers, and inorganic fillers.

[0302] Additives, such as rheology modifiers, fillers, thermal stabilizers or UV stabilizers, fire retardants, lubricants, surfactants, may further include:

[0303] a) film formers, such as esters of dicarboxylic acids (e.g. Lusolvan FBH, BASF) and glycol ethers (e.g. Dowanol, Dow); and

[0304] b) Surfactants, such as fatty acid derivatives (eg Bermadol SPS2543, Akzo) and quaternary ammonium salts.

[0305] In one example, the curable epoxy resin formulation does not include additives.

[0306] Composite Materials

[0307] Disclosed herein are impregnated fiber reinforced materials comprising fibers impregnated with a curable epoxy resin formulation as defined herein.

[0308] The fiber reinforced material may include fibers selected from, but not limited to, fibers consisting of fiberglass, carbon, or aramid (aromatic polyamide).

[0309] In one example, the impregnated fiber-reinforced material includes a compound of any one of Formulas 1, 1a, 1b, 2, 2a, 2b, or a mixture thereof, and a curing agent.

[0310] In one example, the impregnated fiber-reinforced material includes the compound of Formula 3 and a curing agent (eg, a curing agent of any one of Formulas 4, 4a, 4b, 4c, or 4d, or a mixture thereof).

[0311] Also disclosed herein is a composite material comprising a fibrous material in a matrix of a cured epoxy resin, wherein the cured epoxy resin is formed from the curable epoxy resin formulation defined herein.

[0312] In one example, the composite material includes a compound of any one of Formulas 1, 1a, 1b, 2, 2a, 2b, or a mixture thereof, and a curing agent.

[0313] In one example, the composite material includes the compound of Formula 3 and a curing agent of any one of Formulas 4, 4a, 4b, 4c, 4d, or a mixture thereof.

[0314] Also disclosed herein is a method of forming an impregnated fiber reinforced material, the method comprising the steps of:

[0315] a) Provide:

[0316] (i) a curable epoxy resin formulation as defined herein; and

[0317] (ii) fibrous materials; and

[0318] b) combining the resin formulation of step (a)(i) with the fibrous material of step (a)(ii) and subjecting the materials to elevated temperatures which enable curing to form an impregnated fiber reinforced material.

[0319] The fibrous material may include fibers composed of glass fibers, carbon fibers, aramid (aromatic polyamide) fibers.

[0320] In addition, the present invention also discloses the use of a compound of any one of formulas 1, 1a, 1b, 2, 2a, 2b or a mixture thereof as a curable epoxy resin or in the preparation of a curable epoxy resin formulation. The curable epoxy resin formulation can be used in the production of impregnated fiber-reinforced materials or composite materials thereof.

[0321] Furthermore, disclosed herein is a method for preparing a compound of Formula 8, comprising the steps of:

[0322] i) reacting a compound of formula 5 with a compound of formula 6 in the presence of a catalyst to form a compound of formula 7, wherein P is a protecting group, M is a metal and LG is a leaving group:

[0323]

[0324] ii) further reacting the compound of formula 7 with an acid catalyst to form a compound of formula 8:

[0325]

[0326] Also disclosed herein is a method for preparing a compound of Formula 10, comprising the steps of reacting a dihydroxy compound of Formula 8 with a halogenated epoxy compound of Formula 9 to form a compound of Formula 10:

[0327]

[0328] For Formula 9, the alkyl group can be C 1-3 For example, the compound of formula 9 can be epichlorohydrin.

[0329] Protecting groups may be temporary or permanent, are known in the art, and methods for their installation and removal are described in standard references such as Protective groups in Organic Synthesis, TW Greene and P Wutz, John Wiley and Son, 2 nd Edition (1991), the contents of which are incorporated by reference. In Formulas 5 and 7, the following groups can be used to protect the hydroxyl group, such as: acetyl, benzoyl, benzyl, methoxymethyl ether, methoxytrityl, methylthiomethyl ether, trimethylacetyl, tetrahydropyranyl, tetrahydrofuran, trityl, silyl ether (including trimethylsilyl, tert-butyldimethylsilyl, triisopropylsiloxymethyl and triisopropylsilyl ether), alkyl ether (such as methyl ether) and ethoxyethyl ether, protecting group. For example, for Formulas 5 and 7, the protecting group "P" can be an alkyl group, such as a methyl group.

[0330] Examples of metal "M" include, but are not limited to, potassium or sodium.

[0331] Those skilled in the art will appreciate that the term "leaving group" or "LG" and its meaning is a molecular fragment that can be replaced with a stable species, utilizing its binding electrons. Leaving groups are used in organic chemistry to promote covalent bonding between two parts. The term "leaving group" or "LG" includes, but is not limited to, a halide (such as, iodo, bromo and chloro) or a sulfonate group, such as mesylate, tosylate, osylate, p-nitrotoluenesulfonate (nosylate) or benzenesulfonate.

[0332] Example

[0333] raw material

[0334] Certain chemicals mentioned within the specification (including the examples below) can be obtained from the suppliers indicated in Table 1 .

[0335] Table 1 - Suppliers of selected compounds disclosed in the Examples.

[0336]

[0337] instrument

[0338] Nuclear Magnetic Resonance (NMR) Spectroscopy

[0339] Equipped with a 5 mm triple resonance broadband probe (BB / 2 H- 1 H / 19 F) or 5mm reverse broadband probe ( 1 H / 2 H-BB) using a Bruker Avance 400 NMR spectrometer (400.13 MHz 1 The NMR experiments were performed at 40 °C (100 °C) and 100 °C (37 °C). The solutions for NMR analysis were prepared by dissolving the material in 0.6 ml of deuterated chloroform (CDCl3). The NMR experiments were performed with the samples maintained at 25 ± 0.1 °C. 1 The chemical shifts of the H experiments were referenced to the residual solvent signal (CHCl3, δ7.24 ppm). 13 C reference solvent signal (CDCl3, δ77.23 ppm).

[0340] High performance liquid chromatography (HPLC)

[0341] High performance liquid chromatography was performed using a Waters 2695 separation module and a Waters 2996 photodiode array (PDA) or 2414 refractive index (RI) detector. The column was a reversed phase Alltima C18 150×4.6 mm column. The flow rate used was 1.00 mL / min, and the mobile phase was changed from 55% acetonitrile (CAN) / 45% H2O to 65% acetonitrile (CAN) / 35% H2O.

[0342] Electron spray ionization (ESI) mass spectrometry (MS)

[0343] Mass spectrometry was performed on a Thermo Scientific Q Exactive mass spectrometer equipped with a HESI-II ion source. Positive and / or negative ion electrospray mass spectra were recorded over the appropriate mass range set to 140,000 mass resolution. The probe was used with a solvent flow of 0.3 ml / min. In these experiments, the nitrogen nebulizing / desolvation gas used for evaporation was heated to 350°C. The sheath gas flow rate was set to 35 and the auxiliary gas flow rate was set to 25 (both in arbitrary units). The spray voltage was 3.0 kV and the capillary temperature was 300°C.

[0344] Differential Scanning Calorimetry (DSC)

[0345] Using the Mettler DSC821 e DSCDifferential Scanning Calorimetry (DSC) was performed in dynamic mode using approximately 5-10 mg of sample. The sample was placed in a sealed alumina crucible and placed in a furnace under a nitrogen blanket. Cured and uncured samples were heated from 50°C to 300°C at a rate of 10°C / min to determine the optimal curing temperature, get a rough understanding of the reactivity, determine the glass transition temperature of the network, and also get an informal understanding of the degree of cure.

[0346] Abbreviations

[0347] Table 2 lists a series of abbreviations used in this paper.

[0348] Table 2 - Abbreviations of compounds and components described herein

[0349] <![CDATA[ Abbreviation ]]> <![CDATA[ Compound / Component ]]> TPE-Q 1,4-Bis(4-aminophenoxy)benzene TPE-R 1,3-Bis(4-aminophenoxy)benzene 133-APB 1,3-Bis(3-aminophenoxy)benzene BX Bis(4-hydroxyphenyl)-m-xylene BX Bis(4-hydroxyphenyl)-p-xylene 144TGAPP N,N,N,N-Tetraglycidyl 1,4-bis(4-aminophenoxy)benzene 134TGAPB N,N,N,N-Tetraglycidyl 1,3-bis(4-aminophenoxy)benzene 133TGAPB N,N,N,N-Tetraglycidyl 1,3-bis(3-aminophenoxy)benzene 133-BGOPB 1,3-Bis(3-glycidyloxyphenoxy)benzene 144-BGOPB 1,4-Bis(4-glycidyloxyphenoxy)benzene

[0350] Example 1 - Synthesis of N,N,N,N-tetraglycidyl 1,4-bis(4-aminophenoxy)benzene (144-TGAPB)

[0351]

[0352] 1,4-Bis(4-aminophenoxy)benzene(144-TGAPB)

[0353] The materials used in the synthesis of 144-TGAPB are shown below:

[0354] ●1,4-bis(4-aminophenoxy)benzene (TPE-Q) 5.84 g (2.00 × 10 -2 Moore);

[0355] ·Epichlorohydrin (27.75 g, 3.00 × 10 -1 Moore);

[0356] Ethylene dichloride (50 ml);

[0357] Lanthanum nitrate hexahydrate (55 mg);

[0358] ·NaOH(4.00g,1.00×10 -1 Moore); and

[0359] Isopropyl alcohol (30 ml).

[0360] TPE-Q, epichlorohydrin, dichloroethane and lanthanum nitrate (in 2 ml isopropanol) were placed in a 250 ml three-necked round bottom flask. The mixture was refluxed in an oil bath for 90 minutes (oil bath temperature ~100°C, ~87°C in the reaction flask). After 980 minutes, the temperature of the oil bath was reduced to ~80°C, thereby reducing the temperature in the reaction flask to ~70-75°C.

[0361] Grind NaOH into a coarse powder and suspend in isopropanol. Slowly add this suspension in small portions (via a spoon) to the TPE-Q / epichlorohydrin solution over 30 minutes. After the addition is complete, stir the mixture at 70-75°C for another 15 minutes and then cool to room temperature.

[0362] The salts were filtered and the solvent and excess epichlorohydrin were removed in a rotary evaporator (oil pump) at 50°C for 1-2 hours. The residue was then suspended in methanol (50 ml). The solid product was filtered, then resuspended in methanol (50 ml) and filtered again. The white solid product was dried overnight in a vacuum oven at 70°C. The yield was 9.70 g (94%). The product was analyzed by NMR ( 1 H and 13 C)(respectively Figure 1 , images a) and b)), high performance liquid chromatography (HPLC) ( Figure 2 ), mass spectrometry (MS), differential scanning calorimetry (DSC) and thin layer chromatography (TLC).

[0363] TLC (silica plate; solvent: 2% v / v MeOH in DCM) - R f Value ~0.8.

[0364] MS (ESI) m / z 516.

[0365] HPLC: HPLC column Altima C18; mobile phase: 55% acetonitrile / water; single peak retention time (RT) of 17.267 minutes; 95.7% ( Figure 2 ).

[0366] Example 2 - Synthesis of N,N,N,N-tetraglycidyl 1,3-bis(4-aminophenoxy)benzene (134-TGAPB)

[0367]

[0368] 1,3-Bis(4-aminophenoxy)benzene(134-TGAPB)

[0369] The materials used in the synthesis of 134-TGAPB are shown below:

[0370] ·1,3-bis(4-aminophenoxy)benzene (TPE-R) 5.84 g (2.00 × 10 -2 Moore);

[0371] ·Epichlorohydrin (27.75 g, 3.00 × 10 -1 Moore);

[0372] Ethylene dichloride (50 ml);

[0373] Lanthanum nitrate hexahydrate (55 mg);

[0374] ·NaOH(4.0g,1.00×10 -1 Moore); and

[0375] Isopropyl alcohol (30 ml).

[0376] TPE-R, epichlorohydrin, ethylene dichloride, and lanthanum nitrate (in 2 ml isopropanol) were placed in a 250 ml three-necked round bottom flask. The mixture was refluxed in an oil bath for 90 minutes (oil bath temperature ~100°C, ~87°C in the reaction flask). After 90 minutes, the temperature of the oil bath was lowered to ~80°C, thereby lowering the temperature in the reaction flask to ~70-75°C.

[0377] The NaOH was ground to form a coarse powder suspended in isopropanol. The suspension was slowly added to the TPE-R / epichlorohydrin solution in small portions (using a spoon) over 30 minutes. After the addition was complete, the mixture was stirred for another 15 minutes at 70-75°C. The solution was then cooled to room temperature. The salt was filtered and the solvent and excess epichlorohydrin were removed at ~50°C in a rotary evaporator (oil pump) for 1-2 hours. The residue was then suspended in dichloromethane (50ml) and washed with water (50ml) and dried over Na2SO4 (anhydrous). The Na2SO4 was then filtered off (using diatomaceous earth) and the dichloromethane was removed. The product was a black oil with a yield of 9.90g (96% yield). By NMR ( 1 H and 13 C-respectively Figure 3 , images a) and b)), HPLC ( Figure 4 ), MS and TLC to analyze the oily product.

[0378] TLC (silica plate; solvent: 2% v / v MeOH in DCM), R f Value ~0.7.

[0379] MS(ESI)516.

[0380] HPLC: HPLC column Altima C18; mobile phase: 55% acetonitrile / water; single peak RT 18.73 minutes; 92.4% ( Figure 4 ).

[0381] Example 3 - Synthesis of N,N,N,N-tetraglycidyl 1,3-bis(3-aminophenoxy)benzene (133-TGAPB)

[0382]

[0383] 1,3-Bis(3-aminophenoxy)benzene(133-TGAPB)

[0384] The materials used in the synthesis of 133-TGAPB are shown below:

[0385] ·1,3-bis(3-aminophenoxy)benzene (133-APB) 5.84 g (2.00 × 10 -2 Moore);

[0386] ·Epichlorohydrin (27.75 g, 3.00 × 10 -1 Moore);

[0387] Ethylene dichloride (50 ml);

[0388] Lanthanum nitrate hexahydrate (55 mg);

[0389] ·NaOH (4.0 g, 1.00 × 10 -1 Moore); and

[0390] Isopropyl alcohol (30 ml).

[0391] 133-APB, epichlorohydrin, ethylene dichloride, and lanthanum nitrate (in 2 ml isopropanol) were placed in a 250 ml three-necked round bottom flask. The mixture was refluxed in an oil bath for 90 minutes (oil bath temperature ~100°C, ~87°C in the reaction flask). After 90 minutes, the temperature of the oil bath was lowered to ~80°C, thereby lowering the temperature in the reaction flask to ~70-75°C.

[0392] The NaOH was ground to form a coarse powder and then suspended in isopropanol. The suspension was slowly added to the 133-APB / epichlorohydrin solution in small portions (via a spoon) over 30 minutes. After the addition was complete, the mixture was stirred at 70-75°C for another 15 minutes and then cooled to room temperature. The salt was filtered and the solvent and excess epichlorohydrin were removed at ~50°C in a rotary evaporator (oil pump) for 1-2 hours. The residue was then suspended in dichloromethane (50ml), washed with water (50ml) and dried over Na2SO4 (anhydrous). The Na2SO4 was then filtered off (using diatomaceous earth) and the dichloromethane was removed. The product was a yellow oil with a yield of 9.90g (96% yield). By NMR ( 1 H and 13 C-respectively Figure 5 , images a) and b)), HPLC ( Figure 6 ), MS and TLC to analyze the oily product.

[0393] TLC (silica plate; solvent: 2% v / v MeOH in DCM), R f Value ~0.85.

[0394] MS(ESI)516.

[0395] HPLC: HPLC column Altima C18; mobile phase: 55% acetonitrile / water; single peak RT 18.56 minutes; 90.2% ( Figure 6 ).

[0396] Example 4-Synthesis of 1,3-bis(3-glycidyloxyphenoxy)benzene (133-BGOPB)

[0397]

[0398] 1,3-Bis(3-glycidyloxyphenoxy)benzene(133-BGOPB)

[0399] Step 1-Synthesis of 1,3-di(3-methoxyphenoxy)benzene

[0400] This synthesis utilized a modification of the method published in L. Wang et al., Synthesis Communication, 30(2), 227-234, 2000, the contents of which are incorporated herein by reference.

[0401]

[0402] Scheme 1-Synthesis of 1,3-di(3-methoxyphenoxy)benzene

[0403] 3-Methoxyphenol (62.05 g, 5.00 × 10 -1 mol) was added with KOH (30.85 g, 5.50 × 10 -1 mol). Stir the mixture under nitrogen and reflux until the solid is completely dissolved. Remove the solvent first by distillation and then by using a rotary evaporator. -2 mol) and 1,3-dibromobenzene (59 g, 2.50 × 10 -1 mol) was added to the residue, and then stirred at 170-180° C. for 16 hours. The next day, the reaction flask was warmed to about 50° C., and ethanol (200 ml) and water (200 mL) were added to the mixture. The product was extracted with CH2Cl2 (250 ml×2), washed with 5% NaOH aqueous solution (250 ml×2) alone, and finally washed with water (250 ml×2). After drying with Na2SO4, the CH2Cl2 solvent was removed to obtain 46.9 g of a black oil (yield 58.2%). NMR analysis confirmed that it was the expected product and was ready for the next step.

[0404] Step 2-Synthesis of 1,3-bis(3-hydroxyphenoxy)benzene (133-BGOPB)

[0405]

[0406] Scheme 2-Synthesis of 133-BGOPB

[0407] 1,3-bis(3-methoxyphenyloxy)benzene (46.89 g, 1.46 × 10 -1In the mixture of 10% ethyl acetate (500ml), 1 ...

[0408] Step 3 – Synthesis of 1,3-bis(3-glycidyloxyphenoxy)benzene (133-BGOPB)

[0409]

[0410] Scheme 3-Synthesis of 133-BGOPB

[0411] 1,3-bis(3-hydroxyphenoxy)benzene, epichlorohydrin (125.58 g, 1.36 mol) and isopropanol (57 g, 9.50 × 10 -1 mol) were mixed together and stirred and heated at 70°C to complete the synthesis of the epoxy resin. The epoxide ring was closed by adding 100 ml of a 15% w / v NaOH aqueous solution to the above stirring solution in two steps. First, 8-9 ml was added dropwise over 5 minutes, and then the remaining 90 ml was slowly added over 10 minutes. Thereafter, the mixture was heated at 70-75°C for another 30 minutes and then cooled to room temperature. The organic phase (the lower phase containing the product) was separated from the aqueous phase (the upper phase) and washed with water (250 ml×2). The organic solution was then diluted with CH2Cl2 (200 ml), dried over Na2SO4 and filtered. The solvent was removed under vacuum, and the resulting product was a black oil. The product was purified over a short SiO2 column with CH2Cl2 as solvent to obtain a pure product (40 g, 72.6% yield) as a yellow oil. The epoxy equivalent of 133-BGOPB was determined to be 239 mol / g.

[0412] The proton and carbon NMR spectra are shown in Figure 7 , images a) and b). The spectra show that the product is clean and free of impurities. Each peak can be conveniently assigned to the relevant hydrogen or carbon atom, as shown in the inset. The integration of the hydrogen peaks conveniently aligns with the expectations of the 133BGOPB molecule. The synthesis provides a clean synthesis without easily detectable impurities. In addition, Figure 8The HPLC chromatogram in Figure 1 shows the separated components of 133BGOPB, providing clear evidence that the molecule is a pure single-component epoxy resin. For HPLC analysis, a 150 × 4.6 mm Altima C18 column was used. The mobile phase was 65% acetonitrile / water with a flow rate of 1.0 mL min -1 .

[0413] Example 5-Synthesis of 1,4-bis(4-glycidyloxyphenoxy)benzene (144-BGOPB)

[0414] Step 1-Synthesis of 1,4-di(4-acetylphenoxy)benzene

[0415] This synthesis utilized a modification of the method published in GW Yeager et al., Synthesis, 1991, 63-68, the contents of which are incorporated herein by reference.

[0416]

[0417] Scheme 4-Synthesis of 1,4-di(4-acetylphenoxy)benzene

[0418] Anhydrous K2CO3 (64.27 g, 4.65 × 10 -1 1,4-dihydroxybenzene (25.6 g, 2.33 × 10 - 1 mol), 4-fluoroacetophenone (64.17 g, 4.65 × 10 -1 mol) and DMAc (700ml) were added to a stirred solution and the resulting mixture was refluxed overnight under nitrogen. The next day, the mixture was cooled to room temperature and slowly poured into water (2.0L). The product was precipitated as a solid and separated from the solution by filtration. The product was suspended in water (2×1L), filtered and dried in a vacuum oven at 50-70°C for 24 hours. The yield was 74g (92%). NMR analysis confirmed that this was the expected product and was ready for the next step.

[0419] Step 2. Synthesis of 1,4-bis(4-acetoxyphenoxy)benzene

[0420]

[0421] Scheme 5-Synthesis of 1,4-bis(4-acetoxyphenoxy)benzene

[0422] 1,4-di(4-acetylphenyl)benzene (69.2 g, 2.00 × 10 -1mol), m-chloroperbenzoic acid (107.5g) and CHCl (500ml) were stirred under reflux for 5 hours. After this, the reaction mixture was cooled to room temperature, then the solid was filtered and washed with CH Cl (200ml). The combined organic solvent was washed with saturated NaHSO solution (2×250ml), then with saturated NaHCO solution (2×250ml), and finally with water (2×500ml). The organic phase was dried, filtered, and the organic solvent was removed by rotary evaporator at anhydrous Na SO. The product was formed into a yellow solid. The solid product was dried overnight at 50°C in a vacuum oven. The output was 64g (84.6%). NMR shows the product, which is used in the next step.

[0423] Step 3-Synthesis of 1,4-bis(4-hydroxyphenoxy)benzene

[0424]

[0425] Scheme 6-Synthesis of 1,4-bis(4-hydroxyphenoxy)benzene

[0426] 1,4-bis(4-acetoxy)benzene (63.75 g, 1.69 × 10 -1 mol) was added 0.5M KOH / MeOH solution (85ml) and heated to reflux for 1 hour. After this, the solvent was removed by rotary evaporator. The residue was suspended in water (800ml) and acidified with concentrated HCl. The solid product was separated from the solution by filtration and washed twice with water, then dried overnight in a vacuum oven at 70 ℃. The output was 46.5g (93.8%). The product was checked by NMR and prepared for the next step.

[0427] Step 4-Synthesis of 1,4-bis(4-glycidyloxyphenoxy)benzene (144-BGOPB)

[0428]

[0429] Scheme 7-Synthesis of 1,4-bis(4-glycidyloxyphenoxy)benzene (144-BGOPB)

[0430] 1,4-bis(4-hydroxyphenoxy)benzene (46.5 g, 1.58 × 10 -1 mol), epichlorohydrin (146.4 g, 1.58 × 10 - 1mol) and isopropanol (66.4g, 1.11 moles) were dissolved together in a round-bottom flask and heated and stirred at 70°C. After this, 115ml of a 15% w / v NaOH aqueous solution was added to the stirred solution in two steps. First, 10ml was added dropwise over 5 minutes, and then the remaining 105ml was slowly added over 10 minutes. Thereafter, the mixture was kept at 70-75°C for another 30 minutes, and then cooled to room temperature while continuing to stir. The solid in the reaction flask was filtered and washed with water (250ml×2), then suspended in methanol (300ml×2), and filtered again, and dried overnight in a vacuum oven at 50°C. The product was dissolved again in CH2Cl2 (300ml), and very fine insoluble solids were filtered off, and then CH2Cl2 was removed by a rotary evaporator. The yield was 52.0g (81%). 1 H and 13 C NMR again provided evidence of clean desired product, while DSC showed a sharp melting point around 133° C. The epoxide equivalent weight of 144-BGOPB was determined to be 226 mol / g.

[0431] Proton and carbon NMR spectra were Fig. 9 , shown in images a) and b). The spectrum shows that the product is clean and free of impurities. As shown in the inset, each peak can be conveniently assigned to the relevant hydrogen or carbon atom.

[0432] HPLC chromatogram ( Fig.10 ) also indicates the formation of a pure one-component epoxy resin, although in this example, there is a very modest increase in oligomer formation for this synthesis method compared to the 133BGOPB synthesis, as shown by a pair of very small peaks at longer elution times. For HPLC analysis, a 150 × 4.6 mm Altima C18 column was used. The mobile phase was 65% acetonitrile / water with a flow rate of 1.0 mL min -1 .

[0433] Since the 144BGOPB synthesized here is solid, (indicating a pure compound) the melting point was determined using DSC (eg Fig.11 It was found to be 131°C, which is certainly a high melting point for conventional epoxy resins.

[0434] 1,3-Bis(4-glycidyloxyphenoxy)benzene (134BGOPB) can be synthesized using the same method as 144BGOPB.

[0435] Example 6 - Synthesis of meta-substituted hydroxyl precursors of epoxy resins

[0436] Step 1 - Preparation of ZnCl2 / SiO2 Catalyst

[0437] The production of catalyst is crucial to ensure sufficient reaction conversion and selectivity. Zinc chloride supported on silica gel was prepared by impregnating silica gel (Wakogel C-200, 31.7 g) with a solution of anhydrous zinc chloride (5.0 g) in dry methanol (80 ml). The mixture was stirred at room temperature for 0.5 hours, and then methanol was removed using a rotary evaporator. The resulting solid was dried at 150 ° C under vacuum (15 mmHg) for 12 hours.

[0438] Step 2 - Laboratory Scale Synthesis of Bis(4-Hydroxyphenyl)-m-Xylene (BHPmX)

[0439] Phenol (403.30 g, 4.29 moles) and dichloro-m-dimethylbenzene (75 g, 4.29 × 10 -1 mol) was placed in a three-necked round-bottom flask (3 L). Dichloroethane (1.35 L) was added to the flask and the reaction mixture was stirred in a water bath at 10 °C under nitrogen. ZnCl2 / SiO2 (58.7 g, 8.57×10 -2 mol) was slowly added to the reaction mixture and stirred at ~10°C for more than 2 hours. In the latter step, the temperature in the reaction flask was ~5°C at the beginning; after adding ZnCl2 / SiO2 to the mixture, the temperature was slowly raised to ~10°C. Ice was slowly placed in a water bath to maintain the temperature at 10°C.

[0440] After 2 hours, ZnCl2 / SiO2 was filtered and washed with dichloromethane (100 ml). The solvent was then removed on a rotary evaporator (first house vacuum, then oil pump vacuum). During this state, some excess phenol was removed with the solvent. The residual oil (product and a large amount of excess phenol) was washed with 500 ml hot water (65-70°C). The washing process was repeated 10 times. Hot water was used to effectively remove phenol (8 grams of phenol / 100 ml water at room temperature). As more phenol was removed from the product, the oil became thicker.

[0441] After washing, the oil is redissolved in dichloromethane, dried over Na2SO4 (anhydrous) and filtered. The dichloromethane is removed and the product is characterized using NMR, TLC and GC / MS analysis. The yield is typically between 75% and 80%.

[0442] It is very difficult to detect <10% phenol in the product by NMR. TLC is the quickest way to check for any phenol in the product (silica / CH2Cl2 as solvent, R of phenol under UV and iodine). fValues ​​are 0.4 to 0.45), but it is not possible to determine how much % of phenol is present in the product. GC / MS can be used to check the % of phenol and the % of the three isomers in the product, but it cannot detect high boiling oligomers. HPLC would be the best way to determine the % of phenol present in the product, the three isomers, and the oligomers. If the HPLC results show that there is more than 5% phenol in the product (calculated by peak area %), then the product needs to be washed with water again.

[0443] Example 7-Synthesis of para-substituted hydroxyl precursors of epoxy resins.

[0444] Step 1 - Preparation of ZnCl2 / SiO2 Catalyst

[0445] A catalyst was prepared in the same manner as in Step 1 of Example 6.

[0446] Step 2 - Large-scale synthesis of bis(4-hydroxyphenyl)-p-xylene (BHPpX).

[0447] Phenol (21.50 kg, 228.57 moles) and dichloro-p-xylene (4.00 kg, 22.86 moles) were placed in a 100 L reaction vessel. Dichloromethane (50 L) was added to the reaction mixture and stirred while the reaction vessel was slowly heated to 40 °C. When the temperature in the reaction vessel reached 25 °C–30 °C, ZnCl2 / SiO2 (3.13 kg, 4.57 moles) was slowly added to the stirred reaction mixture solution and gently refluxed at 35-40 °C for 3 hours. The HCl released from the reaction needs to be passed through a sodium hydroxide solution. It is calculated that the 4.0 kg scale can produce up to 1170 L of HCl gas.

[0448] After 3 hours, turn off the heater and reduce the volume of the solution in the reaction vessel to about 60L by vacuum (the original volume is about 70L). Filter ZnCl2 / SiO2 and wash with 2-3L of dichloromethane (DCM). The dichloromethane solution is stored in a bucket (5 20L buckets) at room temperature overnight. The product precipitated from the DCM solution is a fine white solid, which will be filtered the next day (the filtrate needs to be preserved because additional products will be collected from the filtrate later). The white solid product is washed with warm (40-50°C) water until the pH of the washing solution becomes neutral. Then wash the white solid product with DCM until the washing solution becomes colorless (may need to wash 2 to 3 times). Finally, the white solid product is dried in air at room temperature for a weekend. The output is about 1.8 to 2.0kg.

[0449] The second batch of product was collected by the following method. DCM was removed from the filtrate. The residual oil (product and excess phenol) was washed with warm (50-60°C) water (40L). The washing process was repeated until the residual oil became a semi-solid or thick slurry (may need 7 times, 40L water). The thick slurry was then suspended in DCM (8-10L) overnight. The product was formed into a fine white solid, which was filtered and washed with DCM until the washing solution became colorless. If the DCM washing is insufficient, the second batch of product will be pink. The white solid product was dried overnight in a vacuum oven at room temperature. The yield was about 1.0-1.2kg. The first and second batches of products were checked by NMR and HPLC, and the overall yield varied between 42 and 48%.

[0450] Example 8 - Isomer Composition of Di-Hydroxyphenyl-m-xylene (BHPmX) and Di-Hydroxyphenyl-p-xylene (BHPpX)

[0451] The ortho- and para-directed nature of the phenol group and the disubstitution of phenol ensure that a range of isomers with various substitution patterns are expected. This is indeed the case and in Fig.12 A typical HLPC chromatogram of is shown in where three major peaks are evident. In addition to these peaks there is some evidence of phenol starting material and higher molecular weight oligomeric species. Based on standard geometric considerations, it was expected that the isomers would consist of 4,4, 2,4 and 2,2 substituted isomers in a combination 1:4:4, respectively. Clearly this is not what is observed as the composition of these isomers is present in a ratio of approximately 16:43:19. This relative composition is commonly found in multiple syntheses of meta-hydroxy compounds. The change in expected composition can be explained by steric constraints that promote para-substitution in favor of the more difficult ortho-substitution. As a result, the relative concentrations of the 4,4 and 2,4 isomers increase at the expense of the 2,2 isomer concentration. In . Fig.12 This is clearly observed in the HLPC chromatogram shown. The HLPC trace also shows that the synthesis of the meta-hydroxy compound contains significant levels of higher molecular weight oligomers. Fig.13 In 1 H NMR spectroscopy indicated that the compound had been synthesized to a high level of purity.

[0452] The HPLC trace of the para-substituted hydroxy compound is shown in Fig.14in which very little presence of the 2,2 isomer was observed. The difference between the meta- and para-substituted dimethylbenzene syntheses here involves the different solubility of the more rigid para-substitution of the central benzene ring compared to the twisted meta-substituted hydroxy compound. The para-substituted ones were found to be less soluble than the meta-position and easily precipitated out of solution during the synthesis. This made the separation easier but the disadvantage was that the 2,2 isomer remained in solution and at the same time was effectively lost during purification. Hence, this is why only two isomers were present and why the yield was much lower than the meta-synthesis. Conversely, the advantage of this lack of solubility is the much lower oligomer concentration levels as they were also found to remain in solution. Fig.15 The NMR spectrum shown in again shows that the para-substituted compound has been synthesized to a high level of purity.

[0453] Overview of Hydroxy and Epoxy Resin Synthesis

[0454] Herein, new epoxy resins made of three benzene groups connected by methylene bonds have been synthesized and their isomeric compositions characterized. The methylene bonds are understood to impart torsional mobility, while the aromatic rings provide thermal stability and resistance to solvent access. The structural differences between the dihydroxy and epoxy resins arise from whether the middle xylene group is meta- or para-substituted. While not influencing the reaction mechanism by which the molecule is formed, the kinked backbone of the meta compound versus the rigid linear backbone of the para compound does have a significant effect on the overall product formed. Some of the key experimental aspects of the synthesis that are unique to the different approaches are as follows:

[0455] BX

[0456] 1. After the reaction, the catalyst was filtered off and DCM was evaporated completely.

[0457] 2. Continuously wash the oily product with water to remove phenol. This is an advantage as it helps the washing process in removing phenol.

[0458] 3. The final product is an oil containing three isomers, high molecular weight oligomers, with a yield of about 75% in the laboratory.

[0459] BX

[0460] 1. After the reaction, the catalyst was filtered off and the volume of DCM was reduced until the product crystallized out of solution.

[0461] 2. The product was filtered to yield a white solid with 3 isomers. However, the third isomer, the 2,2 substituted isomer, was present in an extremely low concentration.

[0462] 3. The final product had a yield of approximately 50% and showed very little evidence of higher molecular weight oligomers.

[0463] Example 9 - Scale-up Synthesis of Bis(Hydroxyphenyl)-p-Xylene (BHPpX)

[0464] In the CSIRO pilot plant, 26 kg of the p-hydroxy compound was synthesized in three separate sessions. The first was a 1 kg trial run to optimize conditions, the second session produced 16.2 kg, and the third session produced approximately 10 kg. However, during scale-up, 2 to 4 kg of product were produced on each occasion due to manufacturing limitations of the pilot plant. Each batch was characterized by HPLC to determine the isomeric composition. Fig.16 A graph showing the respective concentrations of the different isomers including the phenol starting reactant and oligomeric species is shown. During scale-up synthesis, a second crop of product is often obtained from the filtrate as this product is more miscible than the first crop that was initially precipitated. These products are notable in that their isomeric composition is affected by higher levels of oligomers and an increased content of the 2,2-substituted isomer, as expected. Importantly, it shows that the 2,2-substituted isomer is in fact synthesized, but it is simply more soluble in the solvent and therefore does not precipitate in the first case.

[0465] Example 10 - Curing and Characterization of Carbonyl-Linked Aromatic Amines, 1,3-Di(3-aminobenzoyl)benzene (133BABB), 1,3-Di(4-aminobenzoyl)benzene (134BABB), and 1,4-Di(4-aminobenzoyl)benzene (144BABB)

[0466] Resin preparation

[0467] A series of epoxy / amine formulations were blended at a 1:1 epoxide to amine stoichiometry and mixed and degassed on a rotary evaporator at a temperature of 110°C using an oil bath.

[0468] The epoxy resin used was:

[0469] - diglycidyl ether of bisphenol A (BisA);

[0470] - diglycidyl ether of bisphenol F (BisF); and

[0471] -1,4-bis(4-glycidyl ether phenoxy)benzene (144BGOPB).

[0472]

[0473] The amine used is based on a compound of formula 4':

[0474]

[0475] Specifically, the amines tested were:

[0476] -1,3-bis(3-aminobenzoyl)benzene (133BABB);

[0477] -1,3-bis(4-aminobenzoyl)benzene (134BABB); and

[0478] -1,4-bis(4-aminobenzoyl)benzene (144BABB).

[0479] Due to the potentially reactive nature and lack of miscibility in some formulations, mixing is generally stopped once it is clear that the amine has completely dissolved in the epoxy resin and there are no air bubbles.

[0480] The resin is then poured into a preheated silicon mold for bend testing and dynamic mechanical thermal analysis. The mold is preheated at 110°C for a minimum of 1 hour. The epoxy resin is then cured in an air-circulating oven, typically at 177°C for 10 hours, and post-cured at 210°C.

[0481] Exemplary BABB-based resins produced are shown in Table 3. In each case, the cure profile was 177°C for 10 hours, then 210°C for 2 hours.

[0482] Table 3 - Conditions and compounds used to produce cured compositions.

[0483]

[0484] Characterization

[0485] Dynamic mechanical thermal analysis (DMTA) spectra Fig.17 As shown, the typical behavior of high-performance epoxy networks is fully exhibited. In particular, the tangent delta spectrum appears sharp and symmetrical, which is generally attributed to being very uniform and without a large number of chemical defects. 133BABB produces networks with the lowest Tg of 140-170°C (tan delta maximum), while networks cured with 144BABB give the highest, around 160-200°C. The Tg values ​​of the networks cured with 134BABB are very similar to those of 144BABB, suggesting that the Tg value is mainly determined by the substitution pattern on the outer aromatic ring. For each amine, the effect of different epoxy resins follows the same pattern. BisA resin gives the highest Tg value, followed by 144BGBOP and BisF, which have similar Tg values ​​regardless of the amine.

[0486] exist Fig.18The bending properties of the cured networks were compared to each other in Figure 1. In this case, the results were also compared to BisA and BisF resins cured with 4,4-diaminodiphenyl sulfone (44DDS). As shown, the compression modulus and strength properties of the BABB-cured networks are at least as good as those of the BisA and BisF resins, and in fact, show excellent enhancement when cured with 133BABB amine. This is somewhat surprising, as meta-substituted networks typically have lower glass transition temperatures. The failure displacement also suggests an increase in ductility, so curing the BABB amine with different epoxy resins has produced networks with improved strength, stiffness and ductility properties, which are not usually improved simultaneously.

[0487] Fig.19 Results are shown for the weight gain obtained during immersion of the cured epoxy network in methyl ethyl ketone (MEK). Overall, the results show the resistance of the BABB-cured network to MEK uptake. The network cured with 133BABB provided the greatest degree of chemical resistance. The greatest resistance to MEK ingress was achieved using BisF, followed by 144BGBOP, and then BisA.

[0488] Example 11 - Curing and Characterization of Methylene-Linked Aromatic Epoxy Resins, Diamines, 1,3-Bis(3-aminobenzoyl)benzene (133BABB), 1,3-Bis(4-aminobenzoyl)benzene (134BABB), and 1,4-Bis(4-aminobenzoyl)benzene (144BABB) Preparation of Resins

[0489] The formulations used diglycidyl ether of bisphenol F (BisF), di[(glycidyl ether)phenyl)]-m-xylene (BGOPmX), di[(glycidyl ether)phenyl)]-p-xylene (BGOPpX), and diglycidyl ether diphenyl (BGOBP).

[0490]

[0491] The amine hardeners used to cure epoxy resins are 4,4 diaminodiphenyl sulfone (44DDS) and methylene dianiline (MDA).

[0492]

[0493] Sample preparation

[0494] The epoxy resins were conditioned at 100°C for about half an hour and then mixed together under vacuum on a rotary evaporator at about 120°C. They were then placed in a vacuum oven set at about 95°C and -100 kPa for 1 hour to minimize the extent of dissolved gases. The hardener was then added to the epoxy resin so that the total stoichiometry was 1:1 epoxide:amino groups and mixing continued on the rotary evaporator until the hardener was dissolved into the epoxy resin. This lasted for about 1-2 hours, depending on the reactivity of the formulation. During this time, the Teflon coated mold was preheated at 120-150°C for 4 hours so that when mixing was complete, the resin samples were poured into the Teflon molds and cured in an air circulating oven. Due to the higher reactivity of the MDA systems, they were cured at 150°C for 12 hours and then post-cured at 177°C for 3 hours, while the less reactive 4,4DDS system was cured at 177°C for 12 hours and then post-cured at 205°C for 3 hours.

[0495] In order to achieve uniform cure and a homogeneous network, great care must be taken to ensure that the hardener is completely dissolved in the epoxy prior to curing. This is true even if higher temperatures are required to dissolve the amine. If this is not done properly, an inhomogeneous network with very poor properties is obtained. In addition to this, BGOBP epoxy is solid at room temperature, so it must be mixed with 30 mol% BisF epoxy to improve processability.

[0496] Table 4 shows a list of samples prepared in this project along with their cure profiles and post-cure protocols.

[0497] Table 4 - Epoxy / amine formulations prepared in Example 11 and their cure profiles.

[0498]

[0499] Characterization

[0500] Fig. 20 The DMTA analysis is shown in , which shows that the Tg values ​​follow the following trend for the 44DDS and MDA cured systems, respectively: BGOPmX has the lowest Tg, followed by BGOPpX, BisF, and finally the BGOBP blended formulation has the highest, despite containing 30 mol% of BisF epoxy resin. The tan delta traces are observed to be very symmetrical and uniform, indicating that both MDA and 4,4DDS based systems have a simple curing mechanism. However, it should be noted that the 44DDS cured system, epoxy resin, shows a smaller peak at higher temperatures above Tg, which is exacerbated at higher cure temperatures and also increases with continued post-curing. The peaks in the tan delta spectra for the 44DDS and MDA systems are shown in Table 5 and confirm that the Tg values ​​are similar to those found previously.

[0501] Table 5 - Tg values ​​after curing measured by tan delta spectra of the 44DDS and MDA curing system of Example 11

[0502] sample Cured Tg(℃) BGOPpX / 44DDS 169.7 BGOPpX / MDA 128.9 BGOPmX / 44DDS 144.6 BGOPmX / MDA 122.3 BisF / MDA 147.7 BisF / 44DDS 189.7 (70mol%BGOPmX–30mol%BisF) / 44DDS 217.0 (70mol%BGOPmX-30mol%BisF) / MDA 187.1

[0503] Fig.21 The effect of different post-cures on the DMTA spectra is shown. It can be seen that although some additional reactions occur in the rubber region at higher temperatures, the effect on the Tg of the network is negligible. The consistency of the Tg values ​​implies that the curing mechanism is very robust and stable.

[0504] exist Fig. 22 and Fig.23 The compression properties of each network measurement are shown in Fig. 22 The modulus results in reveal that BGOPmX yields the highest modulus, followed by BGOPpX networks, and then BisF networks. The modulus of the rigid-rod biphenyl polymer network is the lowest among them. These results stem from the fact that the modulus of glassy polymers is controlled by short-range motion, free volume, and packing density rather than crosslink density.

[0505] In the case of BGOPmX, the meta-substitution leads to a main chain structure that may provide better filling, reduced free volume and therefore improved modulus. The network of the para-substitution of BGOPpX is a more rigid polymer network, and therefore has a slightly lower modulus. It is conceivable that the network based on diphenyl has a poorer packing density due to its rigid structure, resulting in high free volume, lower density and much lower modulus. On the contrary, yield strain and stress are more controlled by longer range factors (such as crosslinking density), and therefore compared with BisF and rigid rod diphenyl network polymers, these parameters of BGOPpX and BGOPmX epoxy resins are significantly lower.

[0506] Samples similar to those used for compression measurements were placed in MEK and Skydrol (Solutia Inc.) at room temperature for a period of approximately 45 days, and weight uptake was measured at appropriate time intervals. Fig.24A) and b) show the results of each system cured with 44DDS and MDA, respectively, and indicate that compared with the commercially available BisF / 44DDS system, both the diphenyl and BGOPmX epoxy resins cured with 44DDS reduce the level of absorbed MEK. Although in this case, the BGOPmX network is slightly higher than BisF, rather than slightly lower than this, for the corresponding MDA network, the results are similar. However, an important result of this study is that BGOPpX has a much higher MEK uptake level compared to BisF, no matter which amine is used. This can be explained by the expected higher free volume resulting from the reduction in packing efficiency, which itself stems from the more rigid and linear nature of the para-substituted network structure.

[0507] Example 12 - Curing and Characterization of 1,4-bis(4-glycidyloxyphenoxy)benzene (144BGOPB) and 1,3-bis(3-glycidyloxyphenoxy)benzene (133BGOPB) Cured with 44 diaminodiphenyl sulfone (44DDS) and Comparison with Diglycidyl Ether of Bisphenol A (BisA) and Diglycidyl Ether of Bisphenol F (BisF) Cured with 44 diaminodiphenyl sulfone (44DDS)

[0508] Sample preparation

[0509] The epoxy resins 144-BGOPB and 133-BGOPB were each placed in a round bottom flask in an oil bath at about 140°C (133-BGOPB) and 145°C (144-BGOPB) and degassed on a rotary evaporator for 5 minutes. 4,4 diaminodiphenyl sulfone (44DDS) (or 3,3 diaminodiphenyl sulfone (33DDS)) was then slowly added over a period of about 10 minutes and mixing continued until the resin was clear and free of bubbles. The composition was such that the epoxy amine resin was a 1:1 stoichiometric blend at all times. The resin was then poured into a Teflon coated mold that had been preheated to 150°C and cured in an air circulating oven. The prepared formulations and their respective cure curves are exemplified in Table 6.

[0510]

[0511] Table 6 - Cure profiles and characterization methods applied to second generation twist and BisF epoxies.

[0512]

[0513] Characterization

[0514] Fig.25A selection of raw tan delta traces for the 133 and 144BGOPB systems after curing at 177°C for 12 hours are shown and compared to the widely used aerospace epoxy BisF cured with 33DDS and 44DDS under the same conditions. It can be seen that the Tg of the 144BGOPB polymer network is only about 10°C lower than the Tg of the BisF / 44DDS network. However, in comparison, the 133BGOPB / 44DDS cured polymer network is lower by about 43°C.

[0515] Fig.26 The original compressive stress vs. strain curves are shown, which illustrate the differences in the mechanical properties of the 133 and 144BGOPB systems, particularly as they relate to yield and stiffness. The overall results are shown in Table 7. The key point to note is the low modulus of 144BGOPB (1239 MPa) compared to each of the other systems, with the second lowest being the BisF / 4,4DDS system at 1612 MPa. Despite this, the strain at yield of the 144BGOPB network is significantly higher than the other resins, which is a key indicator of the network's ability to act as a twist resin. In addition to this, the yield stress of 144BGOPB is lower, although there may not be a clear trend with respect to stress. The failure stress and strain appear to be similar.

[0516] Table 7 - Compressive mechanical properties of 144-BGOPB and 133-BGOPB based polymer networks and BisF cured with 4,4DDS and 3,3DDS.

[0517]

[0518] Those skilled in the art will appreciate that many changes and / or modifications may be made to the above-described embodiments without departing from the broad general scope of the present disclosure. Therefore, the present embodiments are to be considered in all aspects as illustrative and not restrictive.

Claims

1. A compound of formula 1 or formula 2: in: Each X 1 are identical and are selected from O and C(O); Each X 2 are identical and are C(O); and Each R 1 is hydrogen and each R 2 is an epoxide group, or each R 2 is hydrogen and each R 1 is an epoxide group wherein: (a) When X 1 When is O, the epoxide group is (b) When X 1 When C(O), the epoxide group is and (c) When X 2 When it is C(O), either: (i)R 2 is H, and R 1 yes or (ii) R 1 is H, and R 2 yes 2. The compound according to claim 1, wherein the compound of formula 1 is selected from the compounds of formula 1a: Where X 1 and R 2 As defined in claim 1.

3. The compound according to claim 1, wherein the compound of Formula 1 is selected from the compound of Formula 1b: Where X 1 and R 1 As defined in claim 1.

4. A compound according to any one of claims 1 to 3, wherein each X 1 It is C(O).

5. The compound according to claim 1, wherein the compound of Formula 2 is selected from the compounds of Formula 2a: Where X 2 and R 1 As defined in claim 1.

6. The compound according to claim 1, wherein the compound of Formula 2 is selected from the compounds of Formula 2b: Where X 2 and R 2 As defined in claim 1.

7. A curable epoxy resin formulation comprising the compound of any one of claims 1 to 6 and a curing agent.

8. The curable epoxy resin formulation of claim 7, wherein the curing agent is an aliphatic amine, a cycloaliphatic amine, or an aromatic amine.

9. A curable epoxy resin formulation according to claim 7 or claim 8, wherein the curing agent is a diamine curing agent.

10. A curable epoxy resin formulation comprising an epoxy resin and a curing agent, wherein: The epoxy resin includes a compound of Formula 3: in: Each X is the same and is selected from O, CH2 and C(O); Each R is the same and is an epoxide group selected from: When R is and X is CH2, the CH2 groups are meta with respect to each other; and The curing agent includes a diamine curing agent of Formula 4: wherein each Y is the same and is selected from O, CH2 and C(O).

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