Small-angle X-ray scattering studies of poly(arylethinylene): Molecular conformation in solution and orientational ordering in rod-coil ionomer blends

Poly(pyridyl/phenyl-ethinylene) polymers of tuned rigidity/flexibility were synthesized and their molecular conformations in solution determined by sm all-angle X-ray scattering. These polymers were used as molecularly dispers ed reinforcing components in ionomer blends with partially sulfonated polys tyrene. Homogeneous ionomer blends were formed by acid-base interactions be tween the two blend components. Small-angle X-ray scattering revealed that in the case of rodlike or semiflexible poly(pyridyl/phenyl-ethinylenes) an elongation-induced orientational ordering is obtained. However, blend sampl es prepared with flexible poly(pyridyl/phenyl-ethinylene) polymers do not s how any observable orientation. The orientation parameter varied systematic ally with the rigidity/flexibility of the reinforcing component, as did the Young modulus determined from stress-strain measurements.