The β-phase of polyvinylidene fluoride (PVDF) crystal is polar and has very good piezoelectric and dielectric properties compared with the non-polar α-phase. Benzyltriphenylphosphonium chloride (BTPC) has previously been shown to nucleate the β phase rather than the α phase directly from the melt and is an additive of practical importance. Different amounts of BTPC were melt-blended into PVDF using a miniature twin-screw extruder, and the rheology of the blends was investigated using oscillatory and steady-shear viscometry. It was found that data at different temperatures can be superimposed on the main curve using time-temperature superposition. After adding 0.5% BTPC, the complex viscosity and steady-state shear viscosity increased significantly and decreased slightly with further addition of BTPC. The storage modulus exhibits a steady state at low frequencies, indicating the formation of structures in the melt after the addition of BTPC. The horizontal displacement factors derived from the time-temperature superposition were found to follow an Arrhenius temperature dependence, and the activation energy for flow was obtained for each mixture. Pure PVDF and PVDF films containing 1% and 3% BTPC were melt extruded using a laboratory twin-screw extruder. Films containing 3% BTPC yielded the highest proportion of β-phase crystals (75%). Small angle light scattering results showed that the size of spherulites decreased with the increase of BTPC weight fraction. The permittivity and conductivity of the films at low frequencies increased significantly with increasing BTPC concentration, as did the dielectric loss and AC conductivity. polymer. Eng. SCI., 54:2420–2429, 2014. © 2013 Society of Plastics Engineers

The corrosion inhibition effects of benzyltriphenylphosphonium chloride, l-histidine (L-His) and their mixtures on magnesium alloys in 0.05 wt% NaCl were investigated by electrochemical measurements. At the appropriate concentration and the ratio of BPP to L-His, the inhibition efficiency exceeds 90%. Moreover, the inhibitory effect can still be maintained even after long-term immersion in sodium chloride. This was attributed to the formation of an inhibitor-coated film, which was further supported by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). Finally, a possible inhibition mechanism is proposed based on X-ray photoelectron spectroscopy (XPS) analysis and density functional theory calculations.