PBI-polyaryletherketone PAEK -PEI blends

Blend patent work ° demonstrated tri-blends of PBI (T, 425-435°C), PAEK (Tg 145°C), and PEI (T 218°C), formed by intimately blending by 

DSC analyses indicated that the of PEEK in the blend increased due to the formation of a miscible blend with the PEI. The crystallinity of PEEK was also found to decrease after mixing with the amorphous PEI. Thermal degradation of the PEI was found to be insignificant for the PEI-filled PBI-PEEK at the 10-35% level. Mechanical properties of PBI-PEEK (50/50) were found to be minimally affected with the addition of up to about 10% PEI. PBI and PEI have been demonstrated to be miscible and to exhibit strong molecular interactions. 

PAEKs have good chemical resistance and moderate compressive strength, but poorer mechanical properties at elevated temperatures when compared to PBI. Blends of PBI and PAEK and of PBI and PEI have been reported, the former using a dry blend with a high speed mixer, and the latter using a mutual polar solvent such as DMAc, NMP, or DMF. These have good attributes, but further improvements are still desirable for some applications requiring enhanced properties. 

Applications of such tri-blends include semiconductor devices, including microchips, flat panel displays, and the hke. In the manufacture of such apparatus, such blends can be used as components of the vapor deposition chamber, process housing components, and materials holding fixtures or molds, in order to be inert to the vapor deposition environment and to prevent off-gas contamination. These blends may also be used in components of semiconductor etching, ashing, wafer transportation, and as hard-disc media cassettes where support components may function as a seal, insulator, holding or transportation device which must endure exposure to the harsh processing environments. Further applications for such blends can be found in various industrial, chemical, and petrochemical processes where the temperature resistance in chemical environments extends the life cycle of parts used in such fabrication processes. 

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