Miscible Blends of Poly(siloxane Imide) Segmented Copolymers and Polybenzimidazole as Potential High Performance Aerospace Materials

Titanium and nickel-based alloys belong to the group of difficult-to-cut materials. The machining of these high-temperature alloys is characterized by low productivity and low process stability as a result of their physical and mechanical properties. Major problems during the machining of these materials are low applicable cutting speeds due to excessive tool wear, long machining times, and thus high manufacturing costs, as well as the formation of ribbon and snarled chips. Under these conditions automation of the production process is limited. This paper deals with strategies to improve machinability of titanium and nickel-based alloys. Using the example of the nickel-based alloy Inconel 718 high performance cutting with advanced cutting materials, such as PCBN and cutting ceramics, is presented. Afterwards the influence of different cooling strategies, like high-pressure lubricoolant supply and cryogenic cooling, during machining of TiAl6V4 is shown.

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Titanium 6/4 Single Lap Shear Adhesive Performance of Polyimide Homopolymers and Poly(Siloxane Imide) Segmented Copolymers

MRS Proceedings ◽

10.1557/proc-153-211 ◽

1989 ◽

Vol 153 ◽

Cited By ~ 4

Author(s):

T. H. Yoon ◽

C. A. Arnold ◽

J. E. McGrath

Keyword(s):

Mechanical Properties ◽

Residual Stress ◽

High Performance ◽

Amic Acid ◽

Thermal Cyclization ◽

Thermal And Mechanical Properties ◽

Space Applications ◽

Aromatic Polyimides ◽

Segmented Copolymers ◽

Lap Shear

Polyimides are attractive candidates for advanced electronic and space applications due to their high performance thermal and mechanical properties. However, the typical intractability and insolubility of polyimides has been a disadvantage. Utilization of the soluble intermediate amic acid can, to some extent, circumvent this problem. However, drawbacks to this approach include the hydrolytic instability of the amic acid and the liberation of water during its subsequent thermal cyclization. Residual stress build-up at the imide-substrate interface may occur due to swelling and drying cycles caused by the loss of water and solvent. In addition, the liberation of volatiles from a polyimide adhesive or coating can lead to the creation of voids which may significantly detract from mechanical properties. Polymeric adhesives must flow in order to provide good wetting of adherend surfaces and consolidation of the bond components. Thus, fully imidized, melt and solution processable, high Tg aromatic polyimides are of great interest.

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High Performance Polyquinoline/Bismaleimide Miscible Blends

Chemistry of Materials ◽

10.1021/cm980147d ◽

1998 ◽

Vol 10 (9) ◽

pp. 2462-2469 ◽

Cited By ~ 6

Author(s):

Hari Singh Nalwa ◽

Masahiro Suzuki ◽

Akio Takahashi ◽

Akira Kageyama ◽

Yoshihiro Nomura ◽

...

Keyword(s):

High Performance ◽

Miscible Blends

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A modified tool design for the drilling of high-performance aerospace materials

CIRP Annals ◽

10.1016/j.cirp.2021.04.024 ◽

2021 ◽

Author(s):

I. Iovkov ◽

M. Bücker ◽

D. Biermann

Keyword(s):

High Performance ◽

Tool Design ◽

Aerospace Materials

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Interaction and Enthalpy Recovery Behavior in Polymer Blends of Polysulfone and Carboxylated Polysulfone

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.150-151.612 ◽

2010 ◽

Vol 150-151 ◽

pp. 612-619 ◽

Cited By ~ 2

Author(s):

You Qing Jiang ◽

Yun Bo Zhang

Keyword(s):

Polymer Blends ◽

Polymer Blend ◽

High Performance ◽

Infrared Absorption Spectrum ◽

Repeat Unit ◽

Gel Permeation Chromatography ◽

Two Phase ◽

Miscible Blends ◽

Enthalpy Recovery ◽

Liquid Liquid Phase Separation

Polymer blends of a binary system with limited miscibility are a kind of different surface structure polymer blends which main chains are same as one. The blend of polysulfone (PSf) and carboxylated polysulfone (CPSf) had been made in the solvent of dimethylacelamide (DMAc) or N-methylpyrrolidinone (NMP). The chemical polysulfones containing 0.5,1.0,1.5 and 2.0 carboxylated groups per repeat unit were mixed with Udel 300 polysulfone. The equilibrium time of two-phase polymer in solution presents their degrees of limited miscibility. The two- phase polymers could transfer as miscible blends when they had been annealed at 170 for above 6 days. Annealing of blends below the grass transition temperature(Tg) results in a decrease in enthalpy that is recovered during heating. The enthalpy recovery is visible as an endothermic peak in a differential scanning calorimeter (DSC) scan. The position of this peak depends on the composition of two-phase and on the structure of material itself. Two-sample cells were co-tested in same time for getting several Tg of limited miscible polymer blend and its component respectively. PSf/CPSf polymer blends in liquid-liquid phase separation and molecular weight distribution to be tested by High Performance Gel Permeation Chromatography (GPC). The polymer blends were showing S-O-C strength absorbance between 1000-769/cm and 3300-2500/cm to be detected by Infrared Absorption Spectrum (IR) analysis. Therefore, the reaction and enthalpy of limited miscibility between two-phase of polymer blend PSf/CPSf can be described in the paper.

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High performance heteroaromatic poly(azo-ester)s and their miscible blends: Thermomechanical and conductivity profile

Polymer Science Series B ◽

10.1134/s1560090413090042 ◽

2013 ◽

Vol 55 (11-12) ◽

pp. 556-565 ◽

Cited By ~ 2

Author(s):

Ayesha Kausar ◽

Syed Tajammul Hussain

Keyword(s):

High Performance ◽

Miscible Blends ◽

Conductivity Profile

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Characterization of high-performance polymer blends

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100153725 ◽

1989 ◽

Vol 47 ◽

pp. 350-351

Author(s):

R.T. Chen ◽

J.J. Rafalko ◽

L.C. Sawyer

Keyword(s):

Polymer Blends ◽

High Performance ◽

Complete Understanding ◽

Concentrated Solutions ◽

Aerospace Applications ◽

Performance Requirements ◽

Miscible Blends ◽

High Performance Polymer ◽

End Use

Blending of polymers, a method used to engineer materials to provide specific properties, has been extended to high performance materials being developed for composite applications in the aerospace industry. The high performance requirements of such blends demand a complete understanding of the chemistry and morphology as a function of end-use temperatures. Multidisciplinary protocols for characterization of blends include microscopy, infrared and thermal analysis. The major issues involved in such a study of polymer blends will be described.Recently the Hoechst Celanese polybenzimidazole, [poly-2,2′(m-phenylene)-5,5′ bibenzimidazole], PBI, and the General Electric aromatic polyether imide [poly(2,2′-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane-m-phenylenediimine], Ultem 1000, which are being evaluated for aerospace applications, were found to form miscible blends. The large parts are being fabricated from fibers spun from concentrated solutions (dopes).

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