Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
  • B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
  • B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
  • B32B5/12—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer characterised by the relative arrangement of fibres or filaments of different layers, e.g. the fibres or filaments being parallel or perpendicular to each other
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/20—All layers being fibrous or filamentary
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2255/00—Coating on the layer surface
  • B32B2255/02—Coating on the layer surface on fibrous or filamentary layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
  • B32B2260/02—Composition of the impregnated, bonded or embedded layer
  • B32B2260/021—Fibrous or filamentary layer
  • B32B2260/023—Two or more layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
  • B32B2260/04—Impregnation, embedding, or binder material
  • B32B2260/046—Synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
  • B32B2262/10—Inorganic fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
  • B32B2262/10—Inorganic fibres
  • B32B2262/106—Carbon fibres, e.g. graphite fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
  • B32B2307/202—Conductive
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/54—Yield strength; Tensile strength
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/558—Impact strength, toughness
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/748—Releasability
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F9/00—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
  • D01F9/08—Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments of inorganic material
  • D01F9/12—Carbon filaments; Apparatus specially adapted for the manufacture thereof
  • D01F9/127—Carbon filaments; Apparatus specially adapted for the manufacture thereof by thermal decomposition of hydrocarbon gases or vapours or other carbon-containing compounds in the form of gas or vapour, e.g. carbon monoxide, alcohols
  • D01F9/1273—Alkenes, alkynes
  • D01F9/1275—Acetylene

Definitions

• the present application provides an innovative fiber reinforced polymer composition comprising a reinforcing fiber, an adhesive composition, and at least a nanofibers sheet comprising a substantial amount of nanofibers that are in a plane parallel to the reinforcing fiber and aligned at an angle with respect to the reinforcing fiber's axis, such that mechanical and z- direction electrical conductivity of the cured fiber reinforced polymer composition are enhanced simultaneously and substantially.
• a conventional approach is to toughen the matrix with a submicrometer-sized or smaller soft polymeric toughening agent.
• the toughening agent Upon curing of the fiber reinforced polymer composite, the toughening agent is most likely spatially located inside the fiber bed/matrix region, called the intraply as opposed to the resin-rich region between two plies, called the interply. Uniform distribution of the toughening agent is often expected to maximize Gic.
• Examples of such resin compositions include, US6063839 (Oosedo et al., Toray Industries, Inc., 2000), EP2256163A 1 (Kamae et al., Toray Industries, Inc., 2009) with rubbery soft core/hard shell particles, US6878776B1 (Pascault et al., Cray Valley S.A., 2005) for reactive polymeric particles, US68941 13B2 (Court el al span Atofina, 2005) for block copolymers and US20100280151 Al (Nguyen et al., Toray Industries Inc., 2010) for reactive hard core/soft shell particles.
• US6063839 Olet al., Toray Industries, Inc., 2000
• EP2256163A 1 Korean et al., Toray Industries, Inc., 2009
• Rubbery soft core/hard shell particles examples of such resin compositions include, US6878776B1 (Pascault et al., Cray Valley S.A.
• an interlayer toughening technique could be utilized.
• a thermoplastic additive e.g., polyimide, polyamide
• Gnc is a measure of how well the composite part resists impact loads as opposed to tensile loads in Gic. In this case, cracks generated due to quasi-static bending of the part experience in-plane shear load, which tends to slide one crack face with respect to the other. Examples of such interlayer toughening techniques include US 5,413,847
• CNT carbon nanotube
• An embodiment relates to a fiber reinforced polymer composition
• a fiber reinforced polymer composition comprising an adhesive composition, a reinforcing fiber, and at least a nanofiber sheet comprising nanofibers, wherein the nanofiber sheet is in a plane parallel to the reinforcing fiber.
• the adhesive composition comprises the nanofiber sheet and/or the nanofibers.
• the nanofibers are carbon nanotubes, carbon nanofibers,
• carbonaceous nanofibers organic nanofibers, inorganic nanofibers, metal nanofibers, oxide nanofibers, composite nanofibers of the aforementioned nanofibers and a polymer, or combinations thereof.
• the nanofibers comprise carbon nanotubes.
• an alignment angle between the nanofibers and the reinforcing fibers is greater than zero degree and up to 90 degrees.
• an alignment angle between the nanofibers and the reinforcing fibers is less than about 20 degrees.
• the adhesive composition comprises at least a thermosetting resin and a curing agent.
• the adhesive composition comprises further at least one of an accelerator, a thermoplastic resin, a toughener, an interlayer toughener, or a combination thereof.
• the adhesive composition comprises at least a thermoplastic resin.
• the nanofiber sheet is located spatially at least one of locations between a layer of the reinforcing fibers and a layer of the adhesive composition, between two adhesive composition layers of a same or different kinds, between two reinforcing fiber layers of a same or different kinds, or on one or both surfaces of the layer of the reinforcing fibers impregnated by the adhesive composition, wherein at least one of the reinforcing fiber or the nanofiber is dry or partially or fully impregnated by the adhesive composition.
• the fiber reinforced polymer composition comprises a prepreg.
• Another embodiment relates to a method of manufacturing a fiber reinforced polymer composition
• a method of manufacturing a fiber reinforced polymer composition comprising impregnating one or more adhesive films of the same kind or different kinds onto one side or both sides of a reinforcing fiber layer comprising a plurality of the reinforcing fibers, wherein at least one of the one or more the adhesive films comprises one or more nanofiber sheets comprising a substantial amount the nanofibers that are in a plane parallel to the reinforcing fiber and are aligned at an alignment angle with respect to the reinforcing fiber's axis on one side or both sides of the one or more adhesive films, wherein the nanofibers are sandwiched between two adhesive films, between one side of the reinforcing fiber layer and one adhesive film, on an exposed surface of the impregnated reinforcing fiber by the adhesive composition, or combinations thereof.
• Another embodiment relates to a method of manufacturing a fiber reinforced polymer composition
• a method of manufacturing a fiber reinforced polymer composition comprising impregnating one or more adhesive films of the same kind or different kinds onto one side or both sides of a reinforcing fiber layer comprising a plurality of the reinforcing fibers, and applying one or more nanofiber sheets on one or more exposed surfaces of the impregnated reinforcing fiber by the adhesive composition such that a substantial amount of the nanofibers are aligned at an alignment angle with respect to the reinforcing fiber's axis,
• the nanofibers comprise carbon nanotubes
• the nanofiber sheet in the cured article is located between the reinforcing fiber layer and the cured adhesive composition layer or sandwiched between two cured adhesive composition layers of the same kind or different kinds,
• the nanofiber sheet in the cured article is located between the reinforcing fiber layer and the cured adhesive composition layer or sandwiched between two cured adhesive composition layers of the same kind or different kinds,
• the nanofiber sheet in the cured article is located between the reinforcing fiber layer and the cured adhesive composition layer or sandwiched between two cured adhesive composition layers of the same kind or different kinds.
• the nanofiber sheet in the cured article is located between the reinforcing fiber layer and the cured adhesive composition layer or sandwiched between two cured adhesive composition layers of the same kind or different kinds.
• the nanofiber sheet in the cured article is located between the reinforcing fiber layer and the cured adhesive composition layer or sandwiched between two cured adhesive composition layers of the same kind or different kinds.
• Another embodiment relates to a method of manufacturing a composite article comprising stacking at least a reinforcing layer, an adhesive composition layer, and a nanofiber sheet comprising a substantial amount of the nanofibers that are in a plane parallel to the reinforcing fiber and are aligned at an alignment angle with respect to the reinforcing fiber's axis in a symmetrical or unsymmetrical sequence with respect to the mid-plane of the stack such that the nanofiber sheet is located at least one of locations between two reinforcing fiber layers of the same kind or different kinds, between one reinforcing layer and one adhesive composition layer or in between two adhesive composition layer of the same kind or different kinds, and curing the stack, wherein the nanofiber sheet in the cured article is located between the reinforcing fiber layer and the cured adhesive composition layer, or sandwiched between two cured adhesive composition layers of the same kind or different kinds.
• FIG. 1 shows some examples of aligned nanofiber layer configurations in fiber reinforced polymer compositions having at least one adhesive composition (2), reinforcing fibers (1 ) that are dry or partially or fully impregnated with the at least one adhesive composition, and at least a nanofiber sheet that is dry or partially or fully impregnated with the at least one adhesive composition (3).
• FIG. 2 shows some examples of aligned nanofiber layer configurations in fiber reinforced polymer compositions having at least two different adhesive compositions (2 and 4), reinforcing fibers (1) that are dry or partially or fully impregnated with one of the at least two adhesive compositions, and at least a nanofiber sheet that is dry or partially or fully impregnated with one of the at least two adhesive compositions (3).
• they can refer to less than or equal to ⁇ 5 %, such as less than or equal to ⁇ 2 %, such as less than or equal to ⁇ 1 %, such as less than or equal to ⁇ 0.5 %, such as less than or equal to ⁇ 0.2 %, such as less than or equal to ⁇ 0.1 %, such as less than or equal to ⁇ 0.05 %.
• a fiber reinforced polymer composition refers to a uncured or cured polymer containing material having reinforcing fibers.
• Embodiments of a fiber reinforcing polymer composition include a prepreg, an uncured layup for a composite or a composite.
• a prepreg is a reinforcing or molding material (for example, in the form of a sheet) already impregnated partially or fully with a resin.
• a composite is a cured material having at least reinforcing fibers and a cured resin.
• a nanofiber refers to any fibrous material having a diameter of less than 100 nm.
• the length of the nanofiber could be at least 0.5 micrometers (um), at least 10 um, at least 100 um, or even at least 1 mm,
• the nanofibers can be carbon nanotubes, carbon nanofibers, carbonaceous nanofibers, organic nanofibers, inorganic nanofibers, metal nanofibers, oxide nanofibers, or combinations thereof.
• the nanofibers could be carbon nanotubes (CNTs), which are produced from a method of a state of the art. Examples of such methods are a chemical vapor deposition (CVD) and its derivatives such as low-pressure CVD, super-growth CVD, plasma activated CVD. Single wall, double wall, more than two wall and multiple wall CNTs could be used.
• CVD chemical vapor deposition
• CVD chemical vapor deposition
• its derivatives such as low-pressure CVD, super-growth CVD, plasma activated CVD.
• Single wall, double wall, more than two wall and multiple wall CNTs could be used.
• An embodiment relates to a method of making aligned nanofiber sheets.
• the nanofiber sheet could be made from an assembly of CNTs to form a spinnable forest comprising an assembly of vertically aligned CNTs on a substrate, with the height of at least 10 microns, at least 100 microns, or even at least 1 mm.
• spinnable forests herein and thereafter are referred to substantially vertically aligned nanofiber forests or carpets in that the nanofibers could be drawn into sheets comprising a substantial amount of the nanofibers oriented in the drawing direction.
• the as-drawn sheets are referred to unidirectional (UD) undensified sheets or simply undensified sheets.
• These undensified sheets could have a thickness of at least 50 nm, at least 100 nm or even at least 1 um.
• the undensified sheets Upon contacting a substrate, a solvent, or a polymer solution, the undensified sheets become the densified sheets.
• These densified sheets could have a thickness of at least 10 nm, at least 20 nm or even at least 50 nm and a density of at least 0.001 g/cm 3 , at least 0.01 g/cm 3 , or even at least 0, 1 g/cm 3 .
• Both undensificd sheets and densified sheets are referred to nanofiber sheets.
• nanofiber sheet used in the embodiments herein refers to an assembly of a substantial amount of nanofibers that are aligned in a direction
• “Substantial amount” refers to a quantity of at least 20% of the assembly, at least 30% of the assembly, at least 50% of the assembly, or even at least 70% of the assembly by weight.
• nanofiber prepreg When the undensified sheets are densified by a polymer solution, the resulting nanofiber sheet is termed a "nanofiber prepreg".
• the nanofiber prepreg could have an amount of the polymer by weight of at least 1 %, at least 10%, or even at least 20%, The nanofiber prepreg could have at most 1%, at most 5%, or even at most 10% by weight of the residual amount of the solvent.
• An embodiment relates to a fiber reinforced polymer composition comprising at least a reinforcing fiber, an adhesive composition and a nanofiber sheet, wherein the nanofiber sheet could be undensified sheets, densified sheets, nanofiber prepregs or combinations thereof.
• nanofiber sheet could be made from random CNTs or other nanofiber modified polymer, herein is referred to 'a mat', which can be stretched by a mechanical mean to align a substantial amount of these nanofibers in the applied load direction.
• a nanofiber sheet comprising a mixture of a nanofiber and a polymer such that the mixture can be electrospun to form composite fibers which could be deposited onto a substrate, allowing a substantial amount of the composite fibers to be aligned at an angle.
• Another embodiment relates to functionalization of the aforementioned nanofibers and nanofiber sheets.
• firstly oxygen functional groups are beneficially introduced on the pristine nanofiber' s surface;
• secondly an adhesion promoter may be selected such that one end of the adhesion promoter is capable of covalently bonding to the oxygen functional groups on the nanofiber's surface while another end of the adhesion promoter is capable of promoting or participating in chemical interactions with functional groups in the resin.
• the adhesion promoter acts as a bridge connecting the fiber to the bulk resin during curing.
• a surface treatment such as plasma, UV, corona discharge, vapor of an oxidizing agent, or wet electro-chemical treatment could be used to introduce oxygen functional groups onto the fiber's surface.
• Other functional groups such as nitrogen-containing groups (e.g., an amine groups), sulfur-containing functional groups (e.g., a thio groups), amide groups (e.g., organic amides, sulphonamides, or phosphoramides) could be introduced.
• a reinforcing fiber is a fiber that provides reinforcement within a composite material.
• the reinforcing fiber used in the embodiments herein can be, but not limited to, any of the following fibers and their combinations: carbon fibers, organic fibers such as aramide fibers, silicon carbide fibers, metal fibers (e.g., alumina fibers), boron fibers, tungsten carbide fibers, glass fibers, and natural/bio fibers.
• carbon fibers, especially graphite fibers could be used in the embodiments herein.
• Carbon fibers could have a strength of 2000 MPa or higher, an elongation of 0.5% or higher, and modulus of 200 GPa or higher.
• the morphology and location of the reinforcing fibers used in the embodiments herein are not specifically defined, Any of morphologies and spatial arrangements of fibers such as long fibers in a direction, chopped fibers in random orientation, single tow, narrow tow, woven fabrics, mats, knitted fabrics, and braids can be employed, For applications where especially high specific strength and specific modulus are required, a composite structure where reinforcing fibers could be arranged in a single direction, or cloth (fabric) structures, which are easily handled, could be used in the embodiments herein.
• the adhesive composition could be any resin composition and may include different components such as a thermosetting resin and curing agent/optional accelerator, a toughening agent, a thermoplastic resin, and an interlayer toughener.
• the adhesive composition could also include a nanofiber and/or a nanofiber sheet.
• thermosetting resin could be any resin which can be cured with a curing agent by means of an external energy such as heat, light, electromagnetic waves such as microwaves, UV, electron beam, or other suitable methods to form a three dimensional crosslink network.
• a curing agent is defined as any compound having at least an active group which reacts with the thermosetting resin,
• a curing accelerator can be used to accelerate cross-linking reactions between the thermosetting resin and curing agent,
• thermosetting resin could be selected from, but not limited, epoxy resin, cyanate ester resin, maleimide resin, bismaleimide-triazine resin, phenolic resin, resorcinolic resin, unsaturated polyester resin, diallylphthalate resin, urea resin, melamine resin, benzoxazine resin (e.g., multifunctional n-phenyl benzoxazine resins such as phenolphthaleine based, thiodiphenyl based, bisphenol A based, bisphenol F based, dicyclopentadiene based benzoxazine resins), polyurethane, and their mixtures thereof.
• epoxy resin cyanate ester resin
• maleimide resin bismaleimide-triazine resin
• phenolic resin resorcinolic resin
• unsaturated polyester resin diallylphthalate resin
• urea resin melamine resin
• benzoxazine resin e.g., multifunctional n-phenyl benzoxazin
• An example of a suitable mixture could be a mixture of an epoxy resin and a benzoxazine resin.
• epoxy resins are suitable for the embodiments herein.
• the epoxy resins could be di-functional or higher epoxy resins.
• epoxies are prepared from precursors such as amines (e.g., tetraglycidyldiaminodiphenylmethane, triglycidyl-p- aminophenol, triglycidyl-m-aminophenol and triglycidylaminocresol and their isomers), phenols (e.g., bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, phenol- novolack epoxy resins, cresol-novolac epoxy resins and resorcinol epoxy resins), and compounds having a carbon-carbon double bond (e.g., alicyclic epoxy resins).
• amines e.g., tetraglycidyldiaminodiphenylmethane, triglycidyl-p- aminophenol, triglycidyl-m-aminophenol and triglycidylaminocresol and their isomers
• phenols
• thermosetting resin thermosetting resin
• selected epoxy resins are combined to make 100 parts by weight of an epoxy resin mixture comprising at least a difunctional epoxy resin and a higher than two functional epoxy resin.
• the combined epoxy equivalent weight of the epoxy resin mixture could be at least 50, at least 80, at least 100, or even at least 120.
• an epoxy resin or a mixture of epoxy resins with different functionalities could be mixed with a benzoxazine resin or a mixture of benzoxazines of different kinds.
• the weight ratio of the epoxy resin to the benzoxazine resin could be between 0.01 to 100.
• suitable curing agents for epoxy resins include, but not limited to, benzoxazines, polyamides, dicyandiamide, amidoamines (in particular, aromatic amidoamines, e.g., aminobenzamides, aminobenzanilides, aminobenzenesulfonamides), aromatic diamines (e.g., diaminodiphenylmethane, diaminodiphenylsulfone), aminobenzoates (e.g., trimethylene glycol di-p-aminobenzoate and neopentyl glycol di-p-amino-benzoate), aliphatic amines (e.g., triethylenetetramine, isophoronediamine), cycloaliphatic amines (e.g., isophoron diamine), imidazole derivatives, tetramethylguanidine, carboxylic acid anhydrides (e.g.,
• methylhexahydrophthalic anhydride carboxylic acid hydrazides (e.g., adipic acid hydrazide), phenol-novolac resins and cresol-novolac resins, carboxylic acid amides, polyphenol compounds, polysulfide and mercaptans, and Lewis acid and base (e.g., boron trifluoride ethylamine, tris- (diethylaminomethyl) phenol).
• Lewis acid and base e.g., boron trifluoride ethylamine, tris- (diethylaminomethyl) phenol.
• DICY and DDS a mixture of two or more of the above mentioned curing agents such as DICY and DDS could be utilized.
• the curing agent(s) could be employed in an amount ranging from about 15 to about 50 parts by weight per 100 parts by weight of total thermosetting resin,
• a suitable curing agen is selected from the above list, For examples, if dicyandiamide is used, it will provide the product good elevated-temperature properties, good chemical resistance, and good combination of tensile and peel strength. Aromatic diamines, on the other hand, will give moderate heat and chemical resistance and high modulus. Aminobenzoates will provide excellent tensile elongation though they have inferior heat resistance compared to aromatic diamines. Acid anhydrides will provide the resin matrix low viscosity and excellent workability, and subsequently, high heat resistance after cured.
• Phenol-novolac resins or cresol-novolac resins provide moisture resistance due to the formation of ether bonds, which have excellent resistance to hydrolysis.
• a curing agent having two or more aromatic rings such as 4,4'-diaminodiphenyl sulfone (DDS) could provide high heat resistance, chemical resistance and high modulus.
• accelerator/curing agent pairs for epoxy resins are borontrifluoride piperidine, p-t-butylcatechol, or a sulfonate compound for aromatic amine such as DDS, urea or imidazole derivatives for dicyandiamide, and tertiary amines or imidazole derivatives for carboxylic anhydride or polyphenol compound. If an urea derivative is preferably used, urea derivatives may be compounds obtained by reacting with secondary amines with isocyanates.
• Such accelerators are selected from the group of 3-phenyl-l ,l -dimethylurea, 3-(3,4- dichlorophenyl)-l ,l -dimethylurea (DCMU) and 2,4-toluene bis-dimethyl urea. High heat resistance and water resistance of the cured material are achieved, though it is cured at a relatively low temperature.
• a toughening agent is any material that could be added to the thermosetting resin to enhance the fracture toughness of the thermosetting resin.
• Polymeric and/or inorganic toughening agent can be used to enhance fracture toughness of the thermosetting resin.
• the toughening agent could be uniformly distributed in the cured thermosetting resin or a cured bonded structure comprising the cured thermosetting resin. Particles could be less than 5micron in diameter, less than 1 micron, or even less than 300nm for the shortest dimension.
• Such toughening agents include, but not limited to, branched polymer, hyperbranched polymer, dendrimer, block copolymer, core-shell rubber particles, core-shell (dendrimer) particles, hard core-soft shell particles, soft core-hard shell particles, oxides or inorganic materials with or without surface modification such as clay, polyhedral oligomeric silsesquioxane (POSS), carbonaceous materials (e.g., carbon black, carbon nanotube, carbon nanofiber, fullerene), ceramic and silicon carbide.
• branched polymer branched polymer
• hyperbranched polymer dendrimer, block copolymer
• core-shell rubber particles core-shell (dendrimer) particles
• hard core-soft shell particles hard core-soft shell particles
• soft core-hard shell particles oxides or inorganic materials with or without surface modification such as clay
• PES polyhedral oligomeric silsesquioxane
• carbonaceous materials e.g., carbon black, carbon nano
• block copolymers whose composition as described in US 68941 13 (Court et al., Atofma, 2005) and include "Nanostrength®” SBM (polystyrene-polybutadiene- polymethacrylate), and AMA (polymethacrylate-polybutylacrylate-polymethacrylate), both produced by Arkema,
• block copolymers include Fortegra ⁇ and amphophilic block copolymer described in US 7820760B2 by Dow Chemical.
• core-shell particles include core-shell (dendrimer) particles whose compositions as described in
• polymerizable monomers such as butadiene, styrene, other unsaturated carbon-carbon bond monomer, or their combinations, and a polymeric shell compatible with the epoxy, typically ⁇ polymethylmethacrylate, polyglycidylmethacrylate, polyacr lonitrile or the alike and similar , "JSR SX" series of carboxylated polystyrene/polydivinylbenzene produced by JSR Corporation.
• Keha Paraloid EXL-2655 (produced by Kureha Chemical Industry Co., Ltd.), which is a butadiene alkyl methacrylate styrene copolymer;
• Stafiloid AC-3355 and TR-2122 (both produced by Takeda Chemical Industries, Ltd.), each of which are acrylate methacrylate copolymers;
• PARALOID EXL-261 1 and EXL-3387 (both produced by Rohm & Haas), each of which are butyl acrylate methyl methacrylate copolymers,
• Examples of known oxide particles include Nanopox ⁇ produced by nanoresins AG. This is a master blend of functional ized nanosilica particles and an epoxy.
• thermoplastic resin is a non-metallic material that does not undergo a substantial chemical change in its composition when heated and can be repeatedly softened by heating and hardened by cooling
• a thermoplastic resin could be a synthetic or natural material generally derived from petrochemicals or natural products.
• a thermoplastic resin could be, but is not limited to, the following thermoplastic materials such as polyethylene, polypropylene, polyethylene terephthalate, polyvinyl formal, polyamide, polycarbonate, polyacetal,
• polyphenyleneoxide poly phenylene sulfide, polyarylate, polyester, polyamideimide, polyimide, polyetherimide, polyimide having phenyltrimethylindane structure, polysulfone,
• polyethersulfone polyetherketone, polyetheretherketone, polyaramid, polyethernitrile, polybenzimidazole, their deviratives and their mixtures thereof.
• thermoplastic additives which do not impair the high thermal resistance and high elastic modulus of the resin.
• the selected thermoplastic additive could be soluble in the resin to a large extent to form a homogeneous mixture.
• the thermoplastic additives could be compounds having an aromatic skeleton or a ring structure selected trom tne group consisting of polysulfones, polyethersulfones, polyamides, polyamideimides, polyimides, polyetherimides, polyetherketones, polyetheretherketones, and polyvinyl formals, their derivatives, similar polymers, and mixtures thereof,
• the migrating agent is selected from the group consisting of polyethersulfones, polyetherimides and mixtures thereof.
• Suitable polyethersulfones may have a number average molecular weight of from about 10,000 to about 75,000.
• Interlayer tougheners may be selected from the group consisting of polyethersulfones, polyetherimides and mixtures thereof.
• An interlayer toughener is a material located primarily between interlayers of a composite material to maximize damage tolerance and resistance of the composite material.
• the materials could be thermoplastics, elastomers, or combinations of an elastomer and a thermoplastic, or combinations of an elastomer and an inorganic such as glass.
• the size of interlayer tougheners is preferably no more than 100 ⁇ , more preferably 10-50 ⁇ to keep them in the interlayer after curing. Such particles are generally employed in amounts of up to about 30%, preferably up to about 15% by weight (based upon the weight of total resin content in the composite composition).
• thermoplastic materials includes polyamides.
• Known polyamide particles include SP-500, produced by Toray Industries, Inc., "Orgasole” produced by Atochem, and Grilamid TR-55 produced by EMS-Grivory, nylon-6, nylon-12, nylon 6/12, nylon 6/6, and Trogamid CX by Evonik.
• Another embodiment relates to an interlayer toughener which is a conductive material having an electrical conductivity of at least 10 "13 S/m, at least 10 " '° S/m, or even 10 "5 S/m, a mixture of a conductive material and a non-conductive material having an electrical conductivity of less than 10 " ' 3 S/m, or a combination thereof.
• Examples of conductive materials include, but are not limited to, carbonaceous materials (e.g., carbon particles such as Bellpearl by Airwater Inc., carbon back, carbon nanofibers, carbon nanotubes, graphite, graphene, graphene oxide, graphite nanoplatelets), metal particles, metal oxide particles, indium titanium oxides and conductive material coated organic or inorganic particles such as Micropearl ⁇ by Sekisui Chemical Co., Ltd. Both the conductive and the non-conductive materials could have a shortest dimension of up to 100 ⁇ , up to 50 ⁇ , or even up to 20 ⁇ .
• carbonaceous materials e.g., carbon particles such as Bellpearl by Airwater Inc., carbon back, carbon nanofibers, carbon nanotubes, graphite, graphene, graphene oxide, graphite nanoplatelets
• metal particles metal oxide particles, indium titanium oxides
• conductive material coated organic or inorganic particles such as Micropearl ⁇ by Sekisui Chemical Co., Ltd.
• a fiber reinforced polymer composition comprising a reinforcing fiber, one or more adhesive compositions of same or different kinds and at least one aforementioned nanofiber sheet, wherein the nanofiber sheets could be located somewhere spatially in the fiber reinforced polymer composition after cured.
• the nanofiber sheets can be located between the reinforcing fiber layer and the cured adhesive composition layer or sandwiched between two adhesive composition layers of the same kind or different kinds.
• FIG. 1 shows some examples of spatial location of a nanofiber sheet (3) with respect to a reinforcing fiber layer (1) and an adhesive composition layer (2).
• the reinforcing fiber layer and/or the nanofiber sheet in configurations 1-3 can be partially or fully impregnated by the adhesive composition.
• Configuration 1 can be made by impregnating two resin films on a release backing paper of the adhesive composition onto both sides of the dry reinforcing fiber bed by heat and pressure followed by attaching the nanofiber sheet on both sides of the impregnated reinforcing fiber bed.
• Configuration 3 can be made by attaching the nanofiber sheet onto a film on a release backing paper of the adhesive composition and impregnating the resulting film onto each side of the dry fiber bed by heat and pressure.
• Configuration 2 can be made by impregnating one film with the nanofiber sheet onto one side of the dry reinforcing fiber bed and another film without the nanofiber sheet onto the other side of the reinforcing fiber bed by heat and pressure.
• the nanofiber sheet can be attached on the exposed side of the impregnated fiber bed.
• FIG, 2 shows some examples of spatial location of a nanofiber sheet (3) with respect to a reinforcing fiber layer (1) and two layers of two different kinds of adhesive compositions (2, 4),
• the reinforcing fiber layer and/or the nanofiber sheet in configurations 4-6 can be partially or fully impregnated by the adhesive composition (s).
• Configuration 4 can be made by
• Configuration 5 can be made by impregnating two resin films on a release backing paper of the adhesive composition 2 onto both sides of the dry reinforcing fiber bed by heat and pressure, followed by impregnating two resin films of the adhesive composition 4 containing the nanofiber sheet on both sides of the impregnated reinforcing fiber bed.
• Configuration 6 can be made by impregnating two resin films on a release backing paper of the adhesive composition 2 containing the nanofiber sheet onto both sides of the dry reinforcing fiber bed by heat and pressure, followed by Impregnating two resin films of the adhesive composition 4 on both sides of the impregnated reinforcing fiber bed.
• nanofiber sheet (s) in the cured article can be located between a reinforcing fiber layer and a cured adhesive composition layer or sandwiched between two adhesive composition layers of the same kind or different kinds.
• one embodiment relates to combining an adhesive composition with a reinforcing fiber to produce a curable fiber reinforced polymer composition such as a prepreg that could be subsequently cured to produce a composite.
• a curable fiber reinforced polymer composition such as a prepreg that could be subsequently cured to produce a composite.
• Employable is a wet method in which reinforcing fibers are soaked in a bath of the resin matrix dissolved in a solvent such as methyl ethyl ketone or methanol, and withdrawn from the bath to remove solvent.
• Nanofibers, nanofiber sheets, or nanofiber prepregs can be applied to the exposed surface of the prepreg such that the nanofibers are aligned at an angle with respect to the reinforcing fiber's axis.
• Another method is hot melt method, wherein an adhesive composition is heated to lower its viscosity, directly applied to a layer of a reinforcing fiber to obtain a resin-impregnated prepreg; or alternatively as another method, the adhesive composition is coated on a release paper to obtain a thin film.
• One or more adhesive compositions of same or different kinds could be used, Nanofibers, nanofiber sheets, or nanofiber prepregs can be applied to the exposed surface of the adhesive films such that the nanofibers are aligned at an angle with respect to the reinforcing fiber's axis.
• the nanofiber modified films of one or more different kinds could be consolidated onto both surfaces of the layer of the reinforcing fiber by heat and pressure such that the nanofibers are aligned at an angle with respect to the reinforcing fiber's axis,
• films of the adhesive composition could be impregnated onto the dry reinforcing fiber bed, and nanofibers, nanofiber sheets or nanofiber prepregs can be applied to the exposed surface of the impregnated fiber bed such that the nanofibers are aligned at an angle with respect to the reinforcing fiber's axis.
• the nanofibers could be located in between two films of the same kind or of different kinds, in between the layer of the reinforcing fiber and a film, or on top of the layer of the reinforcing fiber covered by one of the resin compositions, Examples of such prepregs are illustrated in Figures 1 -2.
• the reinforcing fiber layer and/or the nanofiber sheet can be partially or fully impregnated by the adhesive composition (s).
• one or more plies are applied onto to a tool surface or mandrel with a desired stacking sequence. This process is often referred to as tape-wrapping. Heat and pressure are needed to laminate the plies. The tool is collapsible or removed after cured. Curing methods such as autoclave and vacuum bag could be used.
• Autoclave method pressure is provided to compact the plies, while vacuum-bag method relies on the vacuum pressure introduced to the bag when the part is cured in an oven, Autoclave method could be used for manufacturing high quality composite parts.
• the nanofiber sheet could be located somewhere spatially in the cured composite part, in between the reinforcing fiber layer and the cured adhesive composition or in between two cured layers of one or more adhesive compositions of the same kind or different kinds.
• an adhesive composition may be directly applied to reinforcing fibers which were conformed onto a tool or mandrel for a desired part's shape, and cured under heat.
• the methods include, but not limited to, filament-winding, pultrusion molding, resin injection molding and resin transfer molding/resin infusion.
• Nanofiber sheets can be applied to the exposed surface of the
• An embodiment relates to resin film infusion to make a composite article in which dry reinforcing fiber layers, adhesive composition layers and the nanofiber sheets can be stacked in a sequence with as-shown configurations 1 -6, similar configurations, or their combinations and are cured under heat and pressure to make a composite article,
• the nanofiber sheet (s) in the cured article can be located between a reinforcing fiber layer and a cured adhesive composition layer or sandwiched between two adhesive composition layers of same or different kinds,
• T800GC- Toray Industries GPa
• tensile modulus 290 GPa 24K-31E Inc.
• tensile strain 2.0% type-3 sizing for epoxy resin systems (T800G-31).
• CNT-S1 was made as follows. MWCNT forests were synthesized according to a CVD method as follows. A smooth quartz substrate was placed in a horizontal quartz tube furnace. Iron chloride and acetylene gas were used as catalyst and carbon source, respectively, CVD growth was carried out at the furnace temperature of 820C at 10 Torr, Maximum forest height was about 2mm, However, for the following examples a forest height of about 500um was used to draw aligned CNT sheets, which are densified upon contacting a resin film's surface or a prepreg' surface. Multiple CNT sheets can be placed on the resin film to achieve a desired weight fraction.
• an aligned CNT sheet was made by a method such that a CNT sheet drawn from the CNT forest was attached to a release paper on a roller and rotated to form a desired stack of multiple aligned CNT sheets or a web.
• a solvent such as ethanol or a solvent containing a binder polymer (e.g., 5wt% epoxy in ethanol) was applied to the web to densify CNTs to form an aligned CNT paper.
• the web can be infused with a polymer or a mixture of polymers by an available method in the art such as resin infusion, vacuum assisted resin infusion, hot-melt, resin transfer molding, vacuum assisted resin transfer molding, pultrusion molding, resin injection molding, the similar and the alike.
• the CNT paper is ready to be applied on the surface of a resin film or a prepreg.
• CNT-S2 was made in a similar fashion as CNT-S1 , Yet, the functionalized CNTs were obtained by either a corona discharge or a plasma method after they were drawn from a CNT forest to make a CNT sheet.
• CNT-X material was made from short length epoxy functionalized MWCNT (Multi-wall carbon nanotubes) of 1 -5 ⁇ and a mixture of epoxies according to the below recipes in Table 1.
• Oxidized MWCNT and glycidoxypropyltrimethoxy silane (GPS) were purchased from U.S. Research Nanomaterials and Gelest, respectively.
• the CNTs were placed in a solution of 3wt% GPS in methanol/DI water (95/5wt%) and stirred for 90 inin, The solids were removed by a centrifuge and redispersed into fresh methanol. The procedure was repeated two times to obtain a final dispersion of epoxy-functionalized CNT in methanol. The dispersion was mixed with the epoxy mixture and methanol was removed under heat and vacuum.
• Examples 1-3 and Comparative Examples 1-3 demonstrate the effects of the CNTs on mechanical and electrical properties of composites without other types of tough eners.
• the hot resin was first casted into a thin film using a knife coater onto a release paper.
• the film was consolidated onto a bed of fibers on both sides by heat and compaction pressure.
• a UD prepreg having carbon fiber area weight of about 190g/m 2 and resin content of about 35% was obtained.
• the prepregs were cut and hand laid up with the sequence listed in Table 2 for each type of mechanical test, followed an ASTM procedure. Panels were cured in an autoclave at 180°C for 2 hr with a ramp rate of 1.7 C/min and a pressure of 0,59 MPa.
• Resin mixing procedure was similar to previous examples. However, two pots of resin with and without PA particles were made. PA particles were charged to the resin before adding DDS. Two types of resins films with and without PA particles, designated film #2 and film #1 , respectively, were made with the desired area weight to achieve target resin content in the prepreg. To make the prepreg of Comparative Example 4, two films # 1 were first impregnated onto both sides of the fiber bed followed by two films #2.

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• 2013
  • 2013-02-13 WO PCT/US2013/025902 patent/WO2013123023A2/fr not_active Ceased

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