The present invention relates to an optical film having a glass transition temperature of 165° C. or higher, an optical transmittance at 350 nm of 10% or less, an in-plane retardation of 30 nm or less, and a retardation in a thickness direction of 100 nm or less.

Resin composition including an epoxy resin, an epoxy resin curing agent, and a polyimide resin including a specified structural unit provide a high yield after patterning.

Embodiments of the present disclosure feature an intrinsically microporous ladder-type Tröger's base polymer including a repeat unit based on a combination of W-shaped CANAL-type and V-shaped Tröger's base building blocks, methods of making the intrinsically microporous ladder-type Tröger's base polymer, and methods of using the intrinsically microporous ladder-type Tröger's base polymer to separate a chemical species from a fluid composition including a mixture of chemical species. Embodiments of the present disclosure further include ladder-type diamine monomers for reacting to form a Tröger's base in situ, and methods of making the ladder-type diamine monomers using catalytic arene-norbornene annulation.

The present disclosure describes methods of polyimide synthesis and polyimides made therefore. The method includes placing a tetracarboxylic compound and a solvent in a reaction vessel and adding a first amount of a diamine. The first amount of the diamine is not more than 99.5 mol % of the tetracarboxylic compound inside the reaction vessel. The method can include agitating the mixture and determining a viscosity of the mixture. The method can further include adding a second amount of the diamine. The last steps can be repeated until the viscosity increases to a target value. The target viscosity can be correlated to a peak weight-averaged molecular weight of the polyimide.

A method for manufacturing a patterned polyimide aerogel film on a substrate includes: dispensing a polyimide prepolymer sol onto a first portion of a surface of a substrate, a second portion of the surface of the substrate being substantially free of the polyimide prepolymer sol; forming a patterned film of a polyimide prepolymer gel on the substrate from the polyimide prepolymer sol; drying the polyimide prepolymer gel to form a patterned film of a polyimide prepolymer aerogel on the substrate; and curing the polyimide prepolymer aerogel on the substrate to form the patterned polyimide aerogel film on the first portion of the surface of the substrate, the second portion of the surface of the substrate being substantially free of the patterned polyimide aerogel film.

A polyimide precursor composition according to an exemplary embodiment includes an imide precursor having an organic group derived from a cyclic ether group-containing compound. A polyimide film formed using the polyimide precursor composition has improved heat resistance and mechanical properties, and has high absorbance in a wavelength range in an ultraviolet region.

In a first aspect, a polymer composition includes a first polymer derived from a soluble polymer composition having an imide group and a T.sub.g reducing compound having an amine group. The first polymer has a glass transition temperature that is lower than a second polymer derived from the same soluble polymer composition, but without a T.sub.g reducing compound having an amine group. In a second aspect, a coating solution includes a soluble polymer having an imide group and a T.sub.g reducing compound having an amine moiety that can be an amine or a first masked amine that can be converted to an amine, wherein the first masked amine can be chemically converted, thermally converted, photo-converted or dissociated.

A polyimide resin is obtained by polymerizing a modified polyphenylene ether resin with terminal amine groups and tetracarboxylic dianhydride. The polyimide has the following characteristics: the dissipation factor under 10 GHz electromagnetic wave is less than 0.0040; the water absorption rate is less than 0.3%; or, the temperature of glass transition is greater than 250° C.

A dual-cure method for forming a solid polymeric structure is provided. An end-capped, imide-terminated prepolymer is combined with at least one photopolymerizable 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 photopolymerizable olefinic monomer, at least one photoinitiator, and a diamine, is also provided, as are related methods of use.

Disclosed herein is a high thermal resistant polyolefin-based separator including a coating layer containing polyamic acid. Specifically, the separator includes a polyolefin-based substrate film, and a coating layer containing polyamic acid formed on one or both surfaces of the polyolefin-based substrate film, wherein the polyamic acid contains one or more functional groups selected from the group consisting of a sulfone group, a trifluoromethyl group, an alkyl group, and a phenyl ether group. Also, disclosed herein is an electrochemical battery having improved thermal stability by using the separator including a coating layer containing polyamic acid.