Polyether imide composite

In addition to the polybenzimidazole blends with imide-siloxanes, it was also demonstrated that other different polyether imide-siloxane-segmented copolymers of variable composition could be used to modify semi-crystalline polyether ketones (PEEK) by presumably an analogous mechanism. The mechanical properties and transition temperatures of those systems have been reported [124,125], and would appear to be additional suitable candidates for the harsh outer space environment (see Table 4 and Fig. 21). 

Figure 13.6 The variation of the impulse required to cause complete failure of the composites as a function of plate thickness. The arrows indicate that the panels had not failed completely [24]. PEI, polyether imide.

Miscibility of segmented rigid-rod polyimide (PI), viz., biphenyl dianhydride perfluoromethylbenzidine (BPDA-PFMB), and flexible polyether imide (PEI) molecular composites was established by differential scanning calorimetry. The composite films of BPDA-PFMB/PEI were drawn at elevated temperatures above their glass transitions. Tensile moduli of the films were evaluated as a function of composition and draw ratio. Molecular orientations of polyimide were determined by birefringence and wide-angle X-ray diffraction. The crystal orientation behavior of the 80/20 BPDA-PFMB/PEI was analyzed in the framework of the affine deformation model. 

Virgin and recycled polyethylene terephthalate (PET) was blended with polyether-imide (PEI) in proportions between 0 and 50 percent PEI content and samples were examined by differential scaiming calorimetry and Fourier transform infrared spectroscopy. All blends were completely miscible, as indicated by a single glass transition temperature which is dependent on blend composition. Crystallisation rates of PET were retarded strongly at 20 percent PEI content and above, but degree of crystallinity was easily determined from a linear correlation between a structural parameter measured spectroscopically and enthalpy of fusion. Trans conformer activation energy measurement confirmed the effects of PEI content on crystallisation of PET. 9 refs. 

Matrix materials for commercial composites are mainly liquid thermosetting resins such as polyesters, vinyl esters, epoxy resins, and bismaleimide resins. Thermoplastic composites are made from polyamides, polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polysulfone, polyetherim-ide (PEI), and polyamide-imide (PAI). 

Finally Table 1 summarize some properties of the most widely used matrices to composites including thermosets ( xy and phenolics), amorphous thermoplastics (Poly-ether-imide and poly-amide-imide) and semicrystalline ermoplasdcs (Polyether-ether-ketone, poly-phenylene-sulfide and poly-imide). 

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