HYDROGEN-BONDING AND THE PHASE-BEHAVIOR OF ROD COIL MIXTURES

On the basis of a Flory lattice model it has been calculated that sing le phase rod/coil mixtures can be obtained and this is supported by so me recent experimental results. However, in the absence of flexible si de chains attached to the rigid rods, single phase mixtures are only o btained if the interactions between the rod and coil functional groups are very strong (e.g. phenol/pyridine) and the polymers are chemicall y similar (i.e. chi, describing non-specific interactions, is small). If both flexible side chains and hydrogen bonding functional groups ar e attached to the rig rod, however, a much broader range of allowed ch i values is obtained, so that with careful chemical design it should b e possible to obtain a number of miscible rod/coil mixtures.