A method of rivet bonding a workpiece stack-up that includes one or more polymer composite workpieces, such as carbon fiber composite workpieces, involves several steps. In one step, adhesive is applied to a surface of the workpiece stack-up. In another step, workpiecesincluding the polymer composite workpiece(s)are brought together. In yet another step the adhesive is partially or more cured. A rivet is installed through the workpiece stack-up and through the adhesive in another step. The method strengthens the resulting rivet-bonded joint by minimizing or altogether precluding fracture, cracking, and/or delamination thereat.

Described are moisture responsive materials. The materials may have tunable moisture permeability. A material may be a substrate that includes apertures. The apertures are configured to open or close depending on the humidity environment to which the substrate is exposed. The apertures have at least two regions of polymer gel, which may have different amounts of crosslinking. The apertures may be formed from at least two polymer gels having at least two different crosslinker loadings. The materials may be used in articles of manufacture. For example, the materials are used in wearable articles, outdoor articles, medical articles, packaging articles, building articles, filtration/separation articles, and the like.

The present disclosure describes articles, such as medical articles, containing a substrate having disposed thereon a hydrophilic gel material (e.g., a shaped hydrophilic gel material or a coating of a hydrophilic gel material) and methods for making such articles. Methods are provided for making hydrophilic gel materials from a precursor composition that contains a polar solvent and a polymerizable material that is miscible with the polar solvent.

A part made of a fiber-reinforced composite material includes a structure made from a set of fibers supported in a thermosetting resin and a peel ply across all or part of the outer surface of the structure. The part has a gradient of polymerization at the interface between the structure and the peel ply. Also, methods for making such a part and methods for bonding such parts.

A method for bonding composite substrates includes coupling a first co-cure prepreg layer having a first off-set amine to epoxide molar ratio onto a surface of a first composite substrate and coupling a second co-cure prepreg layer having a second off-set amine to epoxide molar ratio onto a surface of a second composite substrate. The first and second composite substrates are cured to the first and second co-cure prepreg layers, respectively, using a first cure cycle (including B-stage and cure temperatures) to form a first and a second co-cure prepreg layer portion. The method further includes coupling the first co-cure prepreg layer portion to the second co-cure prepreg layer portion and applying a second cure cycle to cure the first co-cure prepreg layer portion of the first composite substrate to the second co-cure prepreg layer portion of the second composite substrate to form a monolithic covalently bonded composite structure.

The present disclosure relates to intumescent fireproofing coatings and methods to apply these coatings. In particular, the disclosure relates to epoxy-based intumescent fireproofing coatings and methods of applying these coating having a mesh reinforcement.

One aspect of the present invention provides a composite sheet which comprises a nitride sintered body having a porous structure and a semi-cured product of a thermosetting resin composition impregnated into the nitride sintered body, the line roughness Rz specified by JIS B 0601:2013 of at least one main surface being 10 m or less.

A method of rivet bonding a workpiece stack-up that includes one or more polymer composite workpieces, such as carbon fiber composite workpieces, involves several steps. In one step, adhesive is applied to a surface of the workpiece stack-up. In another step, workpiecesincluding the polymer composite workpiece(s)are brought together. In yet another step the adhesive is partially or more cured. A rivet is installed through the workpiece stack-up and through the adhesive in another step. The method strengthens the resulting rivet-bonded joint by minimizing or altogether precluding fracture, cracking, and/or delamination thereat.

A method for bonding composite structures which includes providing a first and second composite substrate and coupling a co-cure prepreg tape having chemically protected polymerizable functional groups onto a surface of both the first and second composite substrates. The first and second composite substrates are then cured to the co-cure prepreg tape at a first temperature to form a co-cure prepreg tape portion where the first and second composite substrates are fully cured and the co-cure prepreg tape is partially cured. The co-cure prepreg tape portion of the first composite substrate is then coupled to the co-cure prepreg tape portion of the second composite substrate and a deprotection initiator is applied to facilitate deprotection of the chemically protected polymerizable functional groups and cure the co-cure prepreg tape portion of the first and second composite substrates to form a single covalently bonded composite structure.

A composite material includes a metallic bottom flat element, a metallic top flat element, and an intermediate layer made of a thermosetting synthetic material and arranged between the bottom flat element and the top flat element. The intermediate layer includes three or more duromers, with at least one of the duromers being in a cured state and the other ones of the duromers being in an uncured state. The at least one of the duromers has a polymerization temperature between 50 and 100 C., with a second one of the other ones of the duromers having a polymerization temperature between 170 and 220 C. and a third one of the other ones of the duromers having a polymerization temperature between 230 and 260 C.