Multi-body interpenetrating lattices comprise two or more lattices that interlace or interpenetrate through the same volume without any direct physical connection to each other, wherein energy transfer is controlled by surface interactions. As a result, multifunctional or composite-like responses can be achieved by additive manufacturing of the interpenetrating lattices, even with only a single print material, with programmable interface-dominated properties. As a result, the interpenetrating lattices can have unique mechanical properties, including improved toughness, multi-stable/negative stiffness, and electromechanical coupling.

A composite pressure vessel includes: a body including an inner liner which includes a cylindrical portion extending along a longitudinal axis, and which is made of a thermoplastic polymer material; and an outer thermoset reinforcing structure wrapped around the body and made of a continuous fiber reinforced thermoset matrix composite, including reinforcing fibers and a thermoset matrix. The body further includes a thermoplastic reinforcement layer made of a continuous fiber reinforced thermoplastic composite, including reinforcing fiber and a thermoplastic matrix, which is adhered to the cylindrical portion of the inner liner.

Described are methods and systems for a composite structure that allows for out of autoclave curing. Due to the layout of the composite structure, voids within the composite structure, formed out of autoclave, is reduced. The composite structure includes a composite laminate and one or more infusion films. The composite laminate includes a plurality of fiber tows that each include a plurality of fiber strands and a resin. The resin has a first viscosity within a first temperature range. The infusion film is disposed on a surface of the composite laminate and has a second viscosity lower than the first viscosity within the first temperature range. Methods of curing the composite structure are also described.

Methods and apparatus for additive manufactures of complex parts using co-aligned continuous fibers are disclosed. Filament subunits having complex shapes are fabricated and inserted into a mold cavity. The layup is compression molded to form a complex part having high tensile strength.

The problem is solved by the present invention, which aims to provide a prepreg that allows continuous laying-up of prepreg layers while preventing the reinforcing fibers or the matrix resin from being partly deposited on the automated lay-up device, when such a device is used with the aim of producing a fiber-reinforced composite material having a high toughness and impact resistance.

A prepreg comprising the components [A] to [E] given below, meeting the requirements (i) to (iii) given below, and serving to produce a cured product having a reinforcing fiber layer defined as the region ranging from 8% to 92% depth from the surface in the thickness direction that contains a first epoxy resin composition in which 90 mass % or more of the component [A] exists, and two surface resin layers each defined as the region ranging from either surface to a depth of 8% exclusive in the thickness direction that contain a second epoxy resin composition in which 85 mass % or more of the component [E] exists, (i) the second epoxy resin composition includes the components [B] to [E] of which the component [C] accounts for 8 to 24 parts by mass relative to 100 parts by mass of the second epoxy resin composition, (ii) the second epoxy resin composition has a storage elastic modulus G′ in the range of 1.0×10.sup.4 to 3.0×10.sup.6 Pa when measured at 25° C. and an angular frequency of 3.14 rad/s, and (iii) plies of the prepreg laid up after being left to stand for 24 hours at room temperature show a peel strength of 0.1 N/mm or more at 35° C., [A] a carbon fiber, [B] an epoxy resin containing the components [b1] and [b2] specified below, [b1] a di- or less-functional epoxy resin containing, in a molecule, at least one ring structure having four- or more-membered ring and a glycidyl amine group bonded to a ring structure, [b2] a tri- or more-functional epoxy resin, [C] a thermoplastic resin with a weight-average molecular weight of 2,000 to 30,000 g/mol, [D] diaminodiphenyl sulfone, [E] particles having a volume-average particle size of 5 to 50 μm and insoluble in the component [B].

The present invention aims at providing a prepreg for producing a laminate suitable as a structural material, and a laminate, which have excellent tensile shear joining strength, fatigue joining strength, and interlaminar fractural toughness values, and can be firmly integrated with another structural member by welding. The present invention is a prepreg including the following structural components [A], [B], and [C], wherein [C] is present on a surface of the prepreg, [C] is a crystalline thermoplastic resin having a glass transition temperature of 100° C. or higher or an amorphous thermoplastic resin having a glass transition temperature of 180° C. or higher, and the reinforcing fibers [A] are present which are included in a resin area including [B] and a resin area including [C] across an interface between the two resin areas: [A] reinforcing fibers; [B] a thermosetting resin; and [C] a thermoplastic resin.

A fiber-reinforced plastic substrate is described in which a plurality of resins having different properties are firmly compounded and that includes components [A], [B], and [C]: [A] reinforcing fibers; [B] thermoplastic resin (b); and [C] thermoplastic resin (c),
wherein the component [A] is arranged in one direction, in the fiber-reinforced plastic substrate, a resin area including the component [B] and a resin area including the component [C] are present, the resin area including the component [B] is present on a surface of one side of the fiber-reinforced plastic substrate, and a distance Ra.sub.(bc) between Hansen solubility parameters of the component [B] and the component [C] satisfies formula (1):

Ra.sub.(bc)={4(δDB−δDC).sup.2+(δPB−δPC).sup.2+(δHB−δHC).sup.2}.sup.1/2≥8

wherein Ra.sub.(bc), δDB, δDC, δPB, δPC, δHB and δHC are as defined.

The present disclosure relates to multi-compound fiber reinforced composites and methods of making the same using frontal polymerization and targeted photosensitizer additives. In various aspects, the method may include disposing one or more layers in a mold cavity, where each of the one or more layers includes a fiber material and a first compound. The method may further includes disposing a second compound in the mold cavity, where the second compound includes a photosensitizer material. Further still, the method may include initiating photopolymerization of the photosensitizer using an ultraviolet light source, removing ultraviolet light source, and/or completing polymerization of the one or more layers so as to form the fiber-reinforced composite.

A flexible fiber reinforced hose adapted for conveying fluids under pressure. The reinforced hose having a core tube having at least one reinforcement layer surrounding an outer core tube surface. Each reinforcement layer having one or more woven mats, unwoven mats, or bundle of fibers comprising a plurality of reinforcement fibers that has a binder-resin filling at least a portion of the voids of the reinforcement fibers. In some aspects, the binder-resin adheres to the reinforcement fibers and displaces the air voids at the interface between the reinforcement fibers and the binder-resin. The binder-resin has a relatively low viscosity less than at least about 20,000 centipoise at 176° C. and low molecular weight, which allows the reinforcement layer to maintain a low flex modulus while maintaining or increasing tensile modulus. The reinforced hose also has at least one polymer layer that bonds to the binder-resin of the reinforcement layer, preferably being cross-linkable or cross-linked to the polymer layer.

The present invention discloses cured composites having improved surfaces and processes of making and methods of using same. Such processes use ultra-short pulse lasers, for example, a femto-second laser to ablate material without the detrimental heat affected zones of other laser processes. Such process can not only increases surface roughness and clean contaminates, but can also selectively remove the matrix material and expose the surface fibers of cured composites. The treated cured composites have improved thermal and electrical pathways that can dissipate unwanted heat and electricity when two or more prepregs and/or cured composites are bonded or cured to form a single article.