Miscibility of poly(arylene phosphine oxide) systems and bisphenol A poly(hydroxy ether)

A number of new aryl phosphorus-containing polymers were found to be miscib le with the commercially significant bisphenol A-based poly(hydroxy ether)s (PHE) over the entire composition range by differential scanning calorimet ry (DSC) and dynamic mechanical analysis (DMA) measurements of the blends. Both the FTIR and CP-MAS P-31 NMR results suggested extensive hydrogen-bond ing interactions between hydroxyl groups and the phosphonyl groups. Specifi cally, the poly(arylene thioether diphenylphenylphosphine oxide) and phosph orus-containing polyimides were also miscible with PHE, again emphasizing t he importance of phosphonyl groups for generating miscible polymer blends. In contrast, a structurally similar commercial polyimide, Ultem, was not mi scible with PHE. These results suggested that the miscibility was induced m ainly by hydrogen bonding between phosphonyl and hydroxyl groups, rather th an other sites such as carbonyl or ether oxygen atoms and the hydroxyl grou ps. Furthermore, the measurements of proton spin-lattice relaxation times i n the rotating frame (T-1 rho) showed that the phosphorus-containing polyim ide/PHE blends were homogeneous even at about a 4 nm scale.