A dual-cure method for forming a solid polymeric structure is provided. An end-capped, imide-terminated prepolymer is combined with at least one photopolymerisable olefinic monomer, at least one photoinitiator, and a diamine, to form a curable resin composition, which, in a first step, is irradiated under conditions effective to polymerize the at least one olefinic monomer, thus forming a scaffold composed of the prepolymer and the polyolefin with the diamine trapped therein. The irradiated composition is then thermally treated at a temperature effective to cause a transimidization reaction to occur between the prepolymer and the diamine, thereby releasing the end caps of the prepolymer and providing the solid polymeric structure. A curable resin composition comprising an end-capped, imide-terminated prepolymer, at least one photopolymerisable olefinic monomer, at least one photoinitiator, and a diamine, is also provided, as are related methods of use.

The present disclosure relates to how to engineer reversible elasticity in thin films and/or layers and/or substrates, using a repeated Y-shaped motif, which is cut out through the film and/or layer and/or substrate. As an example, using a 75 μm thick polyimide (PI) foil, macroscopic dog-bone shaped structures with a range of geometrical parameters of the Y shape have been prepared according to an embodiment of the present disclosure. The tensile strain response of the film at its point of fracture was then recorded. The structures were also confirmed using finite element modeling. Upon stretching, the PI ligaments locally deflect out of plane, allowing the foil to macroscopically stretch.

Disclosed herein is an apparatus for folding a side extending outward from a cup part in a battery case of a pouch-type secondary battery. The apparatus can include a body having a plate shape, adjacent to the side, and disposed to be elongated in a longitudinal direction of the secondary battery, wherein the body includes, a heating part disposed at one side thereof to heat an inner portion disposed at a relatively inner side of the side, and a pressing part disposed at the other side thereof to press an outer portion disposed at a relatively outer side of the side. When the heating part heats the inner portion, the body rotates to allow the pressing part to press the outer portion.

Disclosed herein is an apparatus for folding a side extending outward from a cup part in a battery case of a pouch-type secondary battery. The apparatus can include a body having a plate shape, adjacent to the side, and disposed to be elongated in a longitudinal direction of the secondary battery, wherein the body includes, a heating part disposed at one side thereof to heat an inner portion disposed at a relatively inner side of the side, and a pressing part disposed at the other side thereof to press an outer portion disposed at a relatively outer side of the side. When the heating part heats the inner portion, the body rotates to allow the pressing part to press the outer portion.

A polyimide precursor solution is disclosed, and a colorless transparent polyimide film manufactured from the polyimide precursor solution. The polyimide precursor solution has diamines, a first dianhydride represented by biphenyl dianhydride, a second dianhydride represented by rigid alicyclic dianhydride, a third dianhydride represented by non-alicyclic dianhydrides and organic solvent. The colorless polyimide films have a modulus of 4.5 GPa or higher, a glass-transition temperature (T.sub.g) of 370° C. or higher, and a yellow index of 3.0 or lower. These polyimide films can be used as substrates for thin film transistor (TFT), touch sensor panel (TSP), and cover window applications in flexible display such as organic light-emitting diode (OLED), flexible liquid crystal display (LCD) and other fields.

A dual-cure method for forming a solid polymeric structure is provided. An end-capped, imide-terminated prepolymer is combined with at least one photopolymerisable olefinic monomer, at least one photoinitiator, and a diamine, to form a curable resin composition, which, in a first step, is irradiated under conditions effective to polymerize the at least one olefinic monomer, thus forming a scaffold composed of the prepolymer and the polyolefin with the diamine trapped therein. The irradiated composition is then thermally treated at a temperature effective to cause a transimidization reaction to occur between the prepolymer and the diamine, thereby releasing the end caps of the prepolymer and providing the solid polymeric structure. A curable resin composition comprising an end-capped, imide-terminated prepolymer, at least one photopolymerisable olefinic monomer, at least one photoinitiator, and a diamine, is also provided, as are related methods of use.

A laser-weldable composition and method using the same, said composition comprising at least one amorphous polyamide made from the polycondensation of at least an acyclic aliphatic diamine comprising at least 10 carbon atoms and/or at least an acyclic aliphatic diacid comprising at least 10 carbon atoms, and at least a phthalic acid selected from the group consisting of terephthalic acid and isophthalic acid, at least one flat glass fiber; and at least one organic dye which absorbs radiation at a wavelength from 800 to 1400 nm.

A laser-weldable composition and method using the same, said composition comprising at least one amorphous polyamide made from the polycondensation of at least an acyclic aliphatic diamine comprising at least 10 carbon atoms and/or at least an acyclic aliphatic diacid comprising at least 10 carbon atoms, and at least a phthalic acid selected from the group consisting of terephthalic acid and isophthalic acid, at least one flat glass fiber; and at least one organic dye which absorbs radiation at a wavelength from 800 to 1400 nm.

A method for forming a composite part of a gas turbine engine. The method includes assembling the composite part of a first composite material and a second composite material. The second composite material defines an outer surface of the composite part, and is selected to be curable at a cure temperature generated by heat from operation of the engine. The first composite material is selected to have an operating temperature limit less than the cure temperature. The method includes placing the composite part within the engine so that, in use, the second composite material is cured by exposure to the heat generated from operation of the engine. The second composite material thermally shields the first composite material from the heat generated from operation of the engine. The method includes operating the engine to cure the second composite material.

A method for forming a composite part of a gas turbine engine. The method includes assembling the composite part of a first composite material and a second composite material. The second composite material defines an outer surface of the composite part, and is selected to be curable at a cure temperature generated by heat from operation of the engine. The first composite material is selected to have an operating temperature limit less than the cure temperature. The method includes placing the composite part within the engine so that, in use, the second composite material is cured by exposure to the heat generated from operation of the engine. The second composite material thermally shields the first composite material from the heat generated from operation of the engine. The method includes operating the engine to cure the second composite material.