A prepreg which is suitable for producing a fiber-reinforced composite material in a short period of time without using an autoclave, can produce a fiber-reinforced composite material in which the occurrence of voids is suppressed and excellent impact resistance is achieved, and has excellent handling properties; and a fiber-reinforced composite material using the prepreg. This prepreg is a prepreg in which a reinforcing fiber [A] arranged in layers is partially impregnated with an epoxy resin composition containing an epoxy resin [B] and a curing agent [C], wherein the impregnation rate φ is 30-95%, and a thermoplastic resin [D] insoluble in the epoxy resin [B] is unevenly distributed on both surfaces of the prepreg. In addition, in the layers of the reinforcing fiber [A], epoxy resin composition-unimpregnated portions are localized on one surface of the prepreg, and the localization parameter a, which defines the degree of localization, is in the range of 0.10<σ<0.45.

Provided is a fiber-reinforced composite material exhibiting high heat resistance and excellent appearance quality. is the composite material is based on an epoxy resin composition which contains constituents [A], [B], and [C] and satisfies conditions (i) and (ii): [A] a tri- or higher functional epoxy resin; [B] an aromatic amine; [C] an imidazole compound;
0.20≤b/a≤0.60; and  (i)
0.002≤c/a≤0.014;  (ii)
wherein a (mol) denotes the number of epoxy groups in 100 g of the epoxy resin composition, b (mol) denotes the number of active hydrogens contained in the constituent [B], and c (mol) denotes the number of imidazole rings contained in the constituent [C]).

The use of a sulfonated polyaryl ether ketone or of a sulfonated non-polymeric aryl ether ketone as a dispersant for a polyaryl ether ketone resin powder in an aqueous solution, and also to a corresponding composition, and to a process for preparing a semifinished product comprising a polyaryl ether ketone resin and reinforcing fibers.

A prepreg having high processability and laminating performance and a method to produce such a prepreg in an industrially advantageous way is described, the prepreg comprising at least the components [A] to [E] shown below, and having a structure incorporating a first layer composed mainly of the component [A] and a first epoxy resin composition that contains the components [B] to [D] but which is substantially free of the component [E], and a second layer composed mainly of a second epoxy resin composition that contains the components [B] to [E] and which is disposed adjacent to each surface of the first layer, the second epoxy resin composition being characterized in that its component [D] has a weight-average molecular weight of 2,000 to 30,000 g/mol and accounts for 5 to 15 parts by mass relative to the total quantity of its components [B] to [E], which accounts for 100 parts by mass, [A] carbon fiber, [B] epoxy resin, [C] curing agent, [D] thermoplastic resin, and [E] particles containing a thermoplastic resin as primary component and having a volume-average particle diameter of 5 to 50 μm.

The present invention provides a thermosetting resin composition characterized by comprising a bismaleimide compound and a triazine compound having a diaminotriazine structure.

A fiber-reinforced polymeric composite structure having chemically active thermoset particles positioned in an interlaminar region between adjacent layers of reinforcement fibers and method of making the same. Upon curing of the composite structure, the chemically active functional groups on the thermoset particles form covalent bonds with the matrix resin surrounding the particles. In one embodiment, the particles are formed of a partially cured thermoset polymer with a degree of cure of less than 100%. In another embodiment, the particles are derived from a thermosettable resin composition, wherein the stoichiometry is such that there is a deficiency or an excess in the amount of curing agent that is necessary for reacting with 100% of the thermoset resin component. In some embodiments, the composition of the chemically active thermoset particles is the same or substantially the same as that of the matrix resin of the composite structure.

A low cost, high selectivity asymmetric polyimide/polyethersulfone (PES) blend hollow fiber membrane, a method of making the membrane and its use for a variety of liquid, gas, and vapor separations such as deep desulfurization of gasoline and diesel fuels, ethanol/water separations, pervaporation dehydration of aqueous/organic mixtures, CO.sub.2/CH.sub.4, CO.sub.2/N.sub.2, H.sub.2/CH.sub.4, He/CH.sub.4, O.sub.2/N.sub.2, H.sub.2S/CH.sub.4, olefin/paraffin, iso/normal paraffins separations, and other light gas mixture separations. The polyimide/PES blend hollow fiber membrane is fabricated from a blend of a polyimide polymer and PES and showed surprisingly unique gas separation property with higher selectivities than either the polyimide hollow fiber membrane without PES polymer or the PES hollow fiber membrane without PES polymer for gas separations such as for H.sub.2/CH.sub.4, He/CH.sub.4, H.sub.2S/CH.sub.4, CO.sub.2/CH.sub.4 separations.

A method for producing a polyester film is provided. The method includes a resin alloy master batch preparation step and a film forming step. The resin alloy master batch preparation step includes melting and kneading a high temperature resistant resin material and a polyester resin material with a twin-screw granulator, and then forming a plurality of resin alloy master batches. In the resin alloy master batch preparation step, a twin-screw temperature of the twin-screw granulator is between 250° C. and 320° C., and a twin-screw rotation speed of the twin-screw granulator is between 300 rpm and 800 rpm. The film forming step includes melting and extruding the resin alloy master batches with to form a polyester film. The polyester film includes a heat resistant layer formed of the plurality of resin alloy master batches so that the heat resistant layer includes the high temperature resistant resin material and the polyester resin material.

A prepreg is provided that has excellent processability and handleability and that can be processed into a cured product with high heat resistance. Also provided is a method to produce such a prepreg in an industrially advantageous way without being restricted by the types and contents of the matrix resin components used. The prepreg includes at least components [A] to [D] as given below and a preliminary reaction product that is a reaction product of the component [B] and the component [C], at least one surface resin in the prepreg having a storage elastic modulus G′ in the range of 1.0×10.sup.3 to 2.0×10.sup.8 Pa as measured at a temperature of 40° C. and an angular frequency in the range of 0.06 to 314 rad/s: [A] carbon fiber, [B] epoxy resin comprising a m- or p-aminophenol epoxy resin [b1] and either a glycidyl ether epoxy resin or a glycidyl amine epoxy resin [b2] that has two or more glycidyl groups in a molecule, [C] curing agent, and [D] thermoplastic resin.

Disclosed are co-continuous immiscible polymer blends of a polysulfone and a polyaryletherketone optionally reinforced with carbon fiber. A method of preparing such a co-continuous immiscible polymer blend of a polysulfone and a polyaryletherketone reinforced with a carbon fiber is also disclosed.