Process for lowering the dielectric constant of polyimides using diamic acid additives

Linear aromatic polyimides with low dielectric constants are produced by adding a diamic acid additive to the polyamic acid resin formed by the condensation of an aromatic dianhydride with an aromatic diamine. The resulting modified polyimide is a better electrical insulator than state-of-the-art commercially available polyimides

An investigation of physical properties of thermoplastic polyimides

Thermoplastic polyimides are a class of promising high temperature polymers for aerospace applications. NASA-developed LARC-TPI is a prominent member of this family of polymers. Its physical characteristics have been measured as a function of its curing schedule. The results and their possible interpretations are discussed

A process for preparing an assembly of an article and a polyimide which resists dimensional change, delamination, and debonding when exposed to changes in temperature

An assembly of an article and a polyimide composition is prepared. The assembly resists dimensional change, delamination, or debonding when exposed to changes to temperature. An article is provided. A polyamic acid solution which yields a polyimide having a low coefficient of thermal expansion (CTE) was prepared. Equimolar quantities of an aromatic diamine and an aromatic dianhydride were reacted in a solvent medium to form a polyamic acid solution. A metal ion containing additive was added to the solution. Examples of this additive are: TbCl3, DyCl3, ErCl3, TmCl3, Al(C5H7O2)3, and Er2S3. The polyamic acid solution was imidized and is combined with the article to form the assembly

Tensile film clamps and mounting block for the rheovibron and autovibron viscoelastometer

A set of film clamps and a mounting block for use in the determination of tensile modulus and damping properties of films in a manually operated or automated Rheovibron is diagrammed. These clamps and mounting block provide uniformity of sample gripping and alignment in the instrument. Operator dependence and data variability are greatly reduced

A process for preparing an assembly of an article and a soluble polyimide which resists dimensional change, delamination, and debonding when exposed to changes in temperature

An assembly of an article and a polyimide is prepared. The assembly resists dimensional change, delamination, or debonding when exposed to changes in temperature. An article is provided. A soluble polyimide resin solution having a low coefficient of thermal expansion (CTE) was prepared by dissolving the polyimide in solvent and adding a metal ion-containing additive to the solution. Examples of the additive are: Ho(OOCCH3), Er(NPPA)3, TmCl3, and Er(C5H7O2)3. The soluble polyimide resin is combined with the article to form the assembly

Polyimide processing additives

A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA

Polyimide processing additives

A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of the additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA

Graded Index Silicon Geranium on Lattice Matched Silicon Geranium Semiconductor Alloy

A lattice matched silicon germanium (SiGe) semiconductive alloy is formed when a {111} crystal plane of a cubic diamond structure SiGe is grown on the {0001} C-plane of a single crystalline Al2O3 substrate such that a orientation of the cubic diamond structure SiGe is aligned with a orientation of the {0001} C-plane. A lattice match between the substrate and the SiGe is achieved by using a SiGe composition that is 0.7223 atomic percent silicon and 0.2777 atomic percent germanium. A layer of Si(1-x), ,Ge(x) is formed on the cubic diamond structure SiGe. The value of X (i) defines an atomic percent of germanium satisfying 0.2277<X<1.0,(ii) is approximately 0.2777 where the layer of Si(1-x)Ge(x)interfaces with the cubic diamond structure SiGe, and (iii) increases linearly with the thickness of the layer of Si(1-x)Ge(x)

Electrically conductive polyimides containing silver trifluoroacetylacetonate

Polyimides with enhanced electrical conductivity are produced by adding a silver ion-containing additive to the polyamic acid resin formed by the condensation of an aromatic dianhydride with an aromatic diamine. After thermal treatment the resulting polyimides had surface conductivities in the range of 1.7.times.10.sup.-3 4.5 .OMEGA..sup.-1 making them useful in low the electronics industry as flexible, electrically conductive polymeric films and coatings

Laser-Induced Fabrication of Metallic Interlayers and Patterns in Polyimide Films

Self-metallizing polyimide films are created by doping polyamic acid solutions with metallic ions and solubilizing agents. Upon creating a film, the film is exposed to coherent light for a specific time and then cured. The resulting film has been found to have a metallic surface layer and a metallic subsurface layer (interlayer). The layer separating the metallic layer has a uniform dispersion of small metal particulates within the polymer. The layer below the interlayer has larger metal particulates uniformly distributed within the polymer. By varying the intensity or time of exposure to the coherent light, three-dimensional control of metal formation within the film is provided