IMMISCIBILITY IN POLYSTYRENE SULFONATED POLYSTYRENE BLENDS

Miscibility in the binary system of deuterated polystyrene and lightly sulfonated polystyrene has been investigated. Small-angle neutron sca ttering was used to evaluate the physical state of deuterated polystyr ene/polystyrene-1.67% sulfonic acid blends over a wide composition ran ge. Scattering behaviour was found to agree with the Debye-Bueche theo ry indicating that the blends were phase-separated at all compositions . A large positive interaction between styrene and styrenesulfonic aci d monomers is believed to be responsible for the observed immiscibilit y.