MISCIBILITY STUDIES OF POLY(STYRENE-CO-4-VINYLBENZENEPHOSPHONIC ACID DIETHYL ESTER) WITH POLY(P-VINYLPHENOL)

The miscibility of styrene copolymers of 4-vinylbenzenephosphonic acid diethyl ester (PSVBDEP) with poly(p-vinylphenol) (PVPh) was studied by using DSC, FTIR, P-31 NMR, and C-13 NMR. Results indicated that the copolymer containing 4.3 mol % VBDEP units was immiscible with PVPh, For the PSVBDEP-7.5/PVPh blends, a single T-g was observed when the content of PSVBDEP-7.5 was at least 60 wt %. Mixing of PSVBDEP-13.3 with PVPh caused mutual precipitation in tetrahydrofuran. The complexes exhibited a single T-g. Three hydrogen bond donors, hexafluoroisopropyl alcohol, phenol, and tert-butyl alcohol, were used to ''calibrate'' the strength of the - C6H4P(O)(OC2H5)(2) group as an acceptor, and the characteristic parameter in the enthalpy-frequency shift relationship was determined. The IR frequency shift of the hydroxyl group of phenol reached 330-350 cm(-1) when mixed with VBDEP and PSVBDEP-13.3, about the same magnitude as in phenol-DMSO and phenol-DMAc mixtures. Evidence for hydrogen-bonding interaction between the phenol and phosphonate groups was obtained from IR, P-31 NMR, and C-13 NMR measurements.