摘要:
A process for preparing polyamides 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% 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.
摘要:
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% 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.
摘要:
A product and the process for preparing the same to improve the moisture resistance properties of epoxidized TGMDA and DGEBA resin systems by chemically incorporating chromium (III) ions therein without impairing the mechanical strength properties of the resins.
摘要:
Self-metallizing, flexible polyimide films with highly reflective surfaces are prepared by an in situ self-metallization procedure involving thermally initiated reduction of polymer-soluble silver(I) complexes. Polyamic acid solutions are doped with silver(I) acetate and solubilizing agents. Thermally curing the silver(I)-doped resins leads to flexible, metallized films which have reflectivities as high as 100%, abrasion-resistant surfaces, thermal stability and, in some cases, electrical conductivity, rendering them useful for space applications.
摘要:
A new fabrication method for nanovoids-imbedded bismuth telluride (Bi—Te) material with low dimensional (quantum-dots, quantum-wires, or quantum-wells) structure was conceived during the development of advanced thermoelectric (TE) materials. Bismuth telluride is currently the best-known candidate material for solid-state TE cooling devices because it possesses the highest TE figure of merit at room temperature. The innovative process described here allows nanometer-scale voids to be incorporated in Bi—Te material. The final nanovoid structure such as void size, size distribution, void location, etc. can be also controlled under various process conditions.
摘要:
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. These clamps and mounting block provide uniformity of sample gripping and alignment in the instrument. Operator dependence and data variability are greatly reduced.
摘要:
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.
摘要:
An assembly of an article and a polyimide composition is prepared. The assembly resists dimensional change, delamination, or debonding when exposed to changes in 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: TbCl.sub.3, DyCl.sub.3, ErCl.sub.3, TmCl.sub.3, Al(C.sub.5 H.sub.7 O.sub.2).sub.3, and Er.sub.2 S.sub.3. The polyamic acid solution was imidized and is combined with the article to form the assembly.
摘要翻译:制备制品和聚酰亚胺组合物的组合物。 当暴露于温度变化时,组件抵抗尺寸变化,分层或剥离。 提供了一篇文章。 制备具有低热膨胀系数(CTE)的聚酰亚胺的聚酰胺酸溶液。 将等摩尔量的芳族二胺和芳族二酐在溶剂介质中反应形成聚酰胺酸溶液。 向溶液中加入含金属离子的添加剂。 该添加剂的实例是:TbCl 3,DyCl 3,ErCl 3,TmCl 3,Al(C 5 H 7 O 2)3和Er 2 S 3。 将聚酰胺酸溶液酰亚胺化并与制品组合以形成组件。
摘要:
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.
摘要:
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.