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

1989 ◽  
Vol 153 ◽  
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.

The effect of bis allyl benzoxazine on the thermal, mechanical and dielectric properties of bismaleimide–cyanate blend polymers

RSC Advances ◽  
2015 ◽  
Vol 5 (72) ◽  
pp. 58821-58831 ◽  
Author(s):  
Yiqun Wang ◽  
Kaichang Kou ◽  
Guanglei Wu ◽  
Ailing Feng ◽  
Longhai Zhuo
Keyword(s):  
Mechanical Properties ◽  
Dielectric Properties ◽  
Polymer Composite ◽  
High Performance ◽  
Cross Linking ◽  
Thermal And Mechanical Properties ◽  
High Performance Polymer ◽  
The Cross

A high-performance polymer composite was fabricated using Bz-allyl/BMI/BADCy resin, in which the BMI/BADCy resin was modified with Bz-allyl to improve its dielectric, thermal and mechanical properties and the cross-linking degree after curing.

High-performance PEN/GF crosslinkable thermoplastic composites: preparation, properties, and crosslinking reaction

2011 ◽  
Vol 45 (24) ◽  
pp. 2587-2592 ◽  
Author(s):  
Jian Yang ◽  
Jiachun Zhong ◽  
Rui Zhao ◽  
Xiaobo Liu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
High Performance ◽  
Thermoplastic Composites ◽  
Crosslinking Reaction ◽  
Thermal And Mechanical Properties ◽  
Continuous Glass Fiber ◽  
Glass Fiber Reinforced ◽  
Properties Of Composites

The continuous glass fiber-reinforced polyarylene ether nitriles (PEN) composites were successfully fabricated from PEN pre-impregnated glass fabric mates and PEN films using a film-stacking method. The work involved heat treatment for crosslinking reaction of PEN, and so it provided an interesting comparison of how heat treatment can influence the properties of composites. Detailed study on heat treatments for crosslinking reaction of PEN in the catalysis of the ZnCl2 at high temperature promoting the thermal and mechanical properties of composites were also investigated. The results showed that the thermal and mechanical properties of composites were enhanced by heat treatment, which is due to the fact that PEN resins could be crosslinked by the catalytic action of ZnCl2 at high temperature and formed triazine rings with a more thermally stable structure.

The Influence of Thermal Annealing on Microstructure and Mechanical Properties in High Performance Liquid Crystal Copolyesters

2012 ◽  
Vol 1373 ◽  
Author(s):  
Adriana Reyes-Mayer ◽  
Amaury Constant ◽  
Angel Romo-Uribe ◽  
Michael Jaffe
Keyword(s):  
Mechanical Properties ◽  
Liquid Crystal ◽  
Thermal Treatment ◽  
Thermal Annealing ◽  
High Performance ◽  
Molecular Conformation ◽  
Liquid Crystal Polymers ◽  
Thermal And Mechanical Properties ◽  
Monomer Composition ◽  
Extruded Films

ABSTRACTIn this research we have focused on the influence of thermal treatment for periods of time on the thermal and mechanical properties of extruded films of a series of high-performance thermotropic liquid crystal polymers (LCPs). The dependence of microstructure, thermal and mechanical properties on the extent of thermal treatment is investigated. Especially synthesized wholly aromatic LCPs based on hydroxybenzoic acid (B), hydroxynaphthoic acid (N), terephthalic acid (TA) and biphenol (BP) are kindly supplied by Hoechst Celanese Research Corp in the form of 50 μm thick extruded films. Thus, the influence of monomer composition is also studied in order to contrast the influence of molecular conformation. Thermal treatments are carried out at temperatures close to the solid-to-nematic transition (Ts→n) for up to several hours under dry air conditions. The results show a profound influence of thermal annealing on morphology and mechanical modulus when annealing is carried out c.a. 40ºC below Ts→n, where solid-to-nematic transition and Young’s modulus are significantly increased.

Naphthalene Containing Polyimide Nanocomposites Hybrid with Organo-Modified Montmorillonite

2006 ◽  
Vol 111 ◽  
pp. 43-46
Author(s):  
B.K. Chen ◽  
S.Y. Tsay ◽  
C.P. Chen
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Dielectric Constant ◽  
Amic Acid ◽  
Aggregate Formation ◽  
Thermal And Mechanical Properties ◽  
Modified Montmorillonite ◽  
Thermal Imidization ◽  
Tetracarboxylic Dianhydride ◽  
Acid Precursor

To improve the thermal and mechanical properties of polyimides, a nanocomposite of naphthalene containing polyimide (PI) was hybridized with Montmorillonite (MMT). The PI was synthesized from a diamine, 2,7-bis (4-aminophenoxy) naphthalene and polymerized with a 3,3’,4,4’-benzophenone tetracarboxylic dianhydride via thermal imidization. PI-MMT nanocomposites were then prepared from a DMAc solution of poly(amic acid) precursor and a DMAc dispersion of MMT which were organo-modified with various amount of n-dodecylamine. Characterization results demonstrated that the introduction of a small amount of MMT (up to 5%) led to enhanced thermal stability and mechanical properties of PI. The 5% weight loss temperature in N2 was increased by 46oC in comparison to pristine PI with an organoclay content of 5%. The CTE and dielectric constant were decreased. However, at organoclay contents higher than 5% these properties were reduced because the organoclay was poorly dispersed and resulted in aggregate formation.

Improving the Performance of High Temperature Piezopolymers for Magnetoelectric Applications

2013 ◽  
Vol 543 ◽  
pp. 439-442 ◽  
Author(s):  
Jon Gutiérrez ◽  
Andoni Lasheras ◽  
Jose Manuel Barandiaran ◽  
Jose Luis Vilas ◽  
Alberto Maceiras ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
High Performance ◽  
Polymeric Materials ◽  
Amorphous Polymers ◽  
Piezoelectric Response ◽  
Laminate Composites ◽  
Aromatic Polyimides ◽  
Orientation Polarization

Piezoelectricity in amorphous polymers is mainly due to the orientation polarization of the molecular dipoles. Aromatic polyimides are high-performance polymeric materials possessing large molecular dipoles. We already reported good magnetoelectric performance of laminate composites with Vitrovac 4040®as magnetostrictive component and the 2,6(b-CN)APB/ODPA (poli 2,6) polyimide as the piezoelectric. Although the piezoelectric response of this polyimide is good, its mechanical properties can be improved. To combine the best mechanical and piezoelectric response in the same polymer, copolyimides have been synthesized by reaction of the 4,4-oxydiphtalic anhydride (ODPA) with a mixture of 1,3-Bis-2-cyano-3-(3-aminophenoxy) phenoxybenzene (diamine 2CN) and 1,3-Bis (3-aminophenoxy) benzene (diamine 0CN). We present the piezoelectric, mechanical and ME performance of laminate composites of these copolyimides.

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