Liquid-liquid (LL) and solid-liquid (SL) transitions for poly(ethylene-co-h
exene-1), EH for short, in isobutane and propane, are measured and calculat
ed with copolymer statistical associating fluid theory. In the range of 4-1
5 wt %, the EH concentration effect is small. Isobutane is found to reduce
the LL pressure but increase the SL temperature, relative to propane. As ex
pected, increasing the EH density increases the SL transition temperature a
nd the LL pressure.