Transport and thermal properties of poly(ether imide)/ acetylene-terminated monomer blends

Blends of an acetylene-terminated monomer (ATM) with a commercially availab le poly(etherimide) (PEI, Ultem(TM))were prepared, crosslinked, and charact erized. Varying degrees of crosslinking were achieved through thermal treat ment at 150-270 degrees C. Incorporation of the uncrosslinked additive into the PEI resulted in reductions in the glass transition temperature, gas pe rmeabilities and selectivities, and thermal stability. These behavior are c onsistent with antiplasticization of the polymer host by the ATM additive. Crosslinking of the actylene-terminated additive led to increases in therma l and chemical stability and improved gas selectivities as compared to the uncrosslinked blend. Gas transport properties are reported as a function of temperature. For the blend composition considered (9 wt% ATM in PEI), the fully crosslinked blend had transport properties which were essentially equ ivalent to the virgin PEI. Further, processing of the blend could be achiev ed in the same manner as for the virgin PEI. The resistance of the crosslin ked blend to chemical dissolution or swelling was markedly improved as comp ared to PEI. (C) 1999 Elsevier Science B.V. All rights reserved.