The invention generally relates to shape memory films that are tri-functionally crosslinked and that comprise multiple, non-terminal, phenylethynyl moieties. In addition, the present invention relates methods of fabricating such films. Due to the improved properties of such SMPs, the SMP designer can program in to the SMP thermomechanical property enhancements that make the SMP suitable, among other things, for advanced sensors, high temperature actuators, responder matrix materials and heat responsive packaging.

A reactive oligomer has a backbone derived from at least one of polyamideimide, polyimide, polyetherimide, polyaryletherketone, polyethersulfone, polyphenylene sulfide, polyamide, polyester, polyarylate, polyesteramide, polycarbonate, polybenzoxazole or polybenzimidazole and functionalized with at least one unreacted functional group capable of thermal chain extension and crosslinking after formation of the reactive oligomer, wherein the reactive oligomer has an M.sub.n of about 250 to about 10,000 g/mol, calculated using the Carothers equation. Compositions comprising the reactive oligomer have at least one other component that includes a second reactive oligomer, an oligomer lacking unreacted functional groups capable of thermal chain extension and crosslinking, a thermoplastic polymer, a thermoplastic polymer having the same backbone repeat units as the reactive oligomer, a filler, or an additive. A method of manufacture of an article comprises heating a composition comprising the reactive oligomer at a sufficient temperature and time to shape and crosslink the reactive oligomer, including additive manufacturing.

A polyimide copolymer, a polyimide film, and a manufacturing method of the polyimide film are provided. The polyimide copolymer includes a plurality of repeating units represented by a following formula (I) and a plurality of repeating units represented by a following formula (II).

##STR00001##

A structural formula of a substituent R.sub.1 is shown as follows:

##STR00002##

A structural formula of a substituent R.sub.2 is shown as follows:

##STR00003##

In addition, the polyimide copolymer has a weight average molecular weight (Mw) of between 30,000 and 200,000.

Provided is a polyimide having a repeating unit represented by the following Formula (1):

##STR00001##

wherein R.sup.1 represents a tetravalent group; R.sup.2 represents a divalent group; provided that at least one of R.sup.1's is represented by the following Formula (2); and among R.sup.2's, at least one group is represented by the following Formula (3), and at least one other group is represented by the following Formula (4):

##STR00002##

Disclosed herein are a polyimide film for graphite sheets and a graphite sheet manufactured using the same. The polyimide film is fabricated by imidizing a precursor composition including: a polyamic acid prepared by reacting a dianhydride monomer with a diamine monomer; and an organic solvent, wherein the diamine monomer includes about 30 mol % to about 70 mol % of 4,4′-methylenedianiline and about 30 mol % to about 70 mol % of 4,4′-oxydianiline based on the total number of moles of the diamine monomer, 4,4′-methylenedianiline and 4,4′-oxydianiline being present in total in an amount of about 85 mol % or more based on the total number of moles of the diamine monomer.

Disclosed herein is provided a method for manufacturing a polyimide film, the method comprising the steps of: preparing a polyamic acid solution; preparing a polyamic add composition by adding 2-3 mole equivalents of a dehydrating agent to the polyamic acid solution; and applying the polyamic acid to a support to form a film, followed by thermosetting the film in a heater.

Present invention is related to a polyimide of formula as following:

##STR00001##

and a ketone-containing alicyclic dianhydride of formula as following:

##STR00002##

wherein: R1, R2, R3, R4 denote hydrogen atom or carbon containing functional group with carbon number at a range of 1-4; R5 denotes diamine group; and n equals to any positive integer.

A black matte polyimide film is provided, the black matte polyimide film includes polyimide, carbon black and polyimide fine powder. The polyimide component is obtained by polymerization of a dianhydride and a diamine, followed by chemical cyclization, in which the dianhydride is pyromellitic dianhydride, and the diamine comprises 5˜15 mol % of p-phenylenediamine and 95˜85 mol % of 4,4′-diaminodiphenyl ether; the carbon black is present in an amount of 2 to 8 wt % of the polyimide film; and the polyimide fine powder is present in an amount of 5 to 10 wt % of the polyimide film, such that the black matte polyimide film has a glossiness between 5 and 30 and a thermal expansion coefficient of less than 41 ppm/° C.

A modified polyimide resin containing a structure represented by general formula (I) below. A polyimide resin containing: a structural unit A derived from a tetracarboxylic dianhydride; and a structural unit B derived from a diamine compound, wherein the structural unit A contains a structural unit derived from a compound having a specific structure in a proportion of 60 mol % or greater.

##STR00001##

The invention generally relates to polymer nanocomposite films that possess shape memory properties at elevated temperatures. Such films can absorb microwaves, are thermally conductive, are electrically conductive and have increased mechanical strength. In addition, the present invention relates to methods of fabricating such films into 3D objects. Due to the improved properties of such films more advanced sensors and microwave shields can be constructed.