PBI-polyetherimide PEI blends

PBI-PEI blends can be useful in severe environmental conditions and have good impact resistance, solvent resistance, and price/performance characteristics. PBIs are generally more expensive, have high moisture regain, but high Tg values and good solvent resistance. PEIs generally have lower Tg values, lack resistance to certain solvents, but are tractable and relatively less expensive. 

Musto and others reported FT IR investigation of the blend system consisting of PBI and poly (etherimide) (PEI, Tg 220°C), poly [2,2 -bis[4-(3,4-dicarboxyphenoxy) phenyl] propane-m-benzenediamine], or commercially available Ultem 1000, showing evidence of hydrogen bonding between 

Various compositions of blended aromatic PBIs and aromatic PEIs can be expected to have approximate linear Tg per weight % of PBI (Fig. 7.12) according to their phase diagrams based on single Tg values from single DSC scans on PBI-PEI blend compositions ranging from 5% to 95% Ultem  

Treatment of the PBI component, via acid protonation of the imidazole ring, should improve the thermo-oxidative stability of the PBI, as well as the 

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