An erosion resistant article such as rotor blades for helicopters and wind turbines having the leading edge surface protected from damage from high speed impingement of rain or sand with a protective coating formed from specific polyurethane or polyurea coating having a defined set of minimum physical properties where the protective coating can be applied as a liquid coating and cured in place or as a preformed complementary shaped covering to protect the leading edge against erosion damage in service.

The present invention provides methods, processes, and systems for the manufacture of three-dimensional articles made of polymers using 3D printing. A layer of prepolymer is deposited on a build plate to form a powder bed. The deposited powder bed is heated to about 50° C. to about 170° C. Then, a solution of activating agent is printed on the powder bed in a predetermined pattern, and a stimulus is applied converting the prepolymer to the final polymer. After a predetermined period of time, sequential layers are printed to provide the three-dimensional article. The three-dimensional object can be cured to produce the three-dimensional article composed of the final polymers.

A heating article includes a substrate having two opposite surfaces, at least one of which is opaque, and a heat-stable coating arranged on the opaque surface. The heat-stable coating includes an at least two-color decoration having continuous tones and being provided in the form of a continuous or discontinuous layer.

In a first aspect, a polymer film includes a polyimide. The polyimide includes one or more dianhydrides and one or more diamines. Each of the dianhydrides and diamines is selected from the group consisting of crankshaft monomers, flexible monomers, rigid rotational monomers, rigid non-rotational monomers, and rotational inhibitor monomers. The polymer film has a D.sub.f of 0.005 or less, a water absorption of 2.0% or less and a water vapor transport rate of 50 (g×mil)/(m.sup.2×day) or less. In a second aspect, a metal-clad laminate includes the polymer film of first aspect and a first metal layer adhered to a first outer surface of the polymer film. In a third aspect, an electronic device includes the polymer film of the first aspect.

A rubber-metal bonded article with an adhesion promoter in the rubber selected from neoalkoxy zirconates and polyimides. Articles requiring compressed rubber exhibit improved retention of compressive strain after assembly of the article and activation of the adhesion promoter. Also claimed is a method wherein a rubber composition may be fully cured, then assembled between two substrates under compression, then the adhesion promoter activated to form the bond.

A rapid, scalable methodology for graphene dispersion and concentration with a polymer-organic solvent medium, as can be utilized without centrifugation, to enhance graphene concentration.

An endless belt comprising a polyimide-based substrate layer. A plurality of boron nitride nanotubes are dispersed in the polyimide.

A poly(amide-imide) copolymer film having a tensile modulus of greater than or equal to 5.4 GPa, and a yellowness index of less than or equal to 3.6, wherein the poly(amide-imide) copolymer film is a reaction product of an aromatic dianhydride including biphenyl tetracarboxylic dianhydride and 4,4′-hexafluoroisopropylidene diphthalic dianhydride, an aliphatic dianhydride including 1,2,3,4-cyclobutane tetracarboxylic dianhydride, an aromatic diamine including 2,2-bis(trifluoromethyl) benzidine, and an aromatic dicarbonyl compound including terephthaloyl dichloride.

A cover window for a display includes a multilayer polymer film. The multilayer polymer film includes a first transparent, colorless polymer layer having a first elastic modulus and a second transparent, colorless polymer layer having a second elastic modulus. Each of the first and second transparent, colorless polymer layers include a polyimide, a polyamide imide, or a block copolymer of a polyimide. The polymers of both the first and second transparent, colorless polymer layers are cross-linked. The first elastic modulus is different from the second elastic modulus. The first and second transparent, colorless polymer layers are bonded by consolidation and cross-linking. The first transparent, colorless layer of the multilayer polymer film is the layer farthest from the display.

A polyamide acid of the present invention contains, as a diamine component, 2,2-bistrifluoromethylbenzidine and trans-1,4-cyclohexanediamine, and contains, as a tetracarboxylic acid dianhydride component, a pyromellitic acid anhydride and a 3,3,4,4-biphenyltetracarboxylic acid dianhydride. A ratio of the trans-1,4-cyclohexanediamine to a total amount of the diamine is preferably 0.5-40 mol %. A polyimide is obtained by dehydration ring closure of the polyamide acid.