Rheological properties in blends of poly(aryl ether ether ketone) and liquid crystalline poly(aryl ether ketone)

Abstract

Rheological properties of the blends of poly(aryl ether ether ketone) (PEEK) with liquid crystalline poly(aryl ether ketone) containing substituted 3-trifluoromethylbenzene side group (F-PAEK), prepared by solution precipitation, have been investigated by rheometer. Dynamic rheological behaviors of the blends under the oscillatory shear mode are strongly dependent on blend composition. For PEEK-rich blends, the systems show flow curves similar to those of the pure PEEK, i.e., dynamic storage modulus GЈ is larger than dynamic loss modulus GЉ, showing the feature of elastic fluid. For F-PAEK-rich systems, the rheological behavior of the blends has a resemblance to pure F-PAEK, i.e., GЉ is greater than GЈ, showing the characteristic of viscous fluid. When the PEEK content is in the range of 50 -70%, the blends exhibit an unusual rheological behavior, which is the result of phase inversion between the two components. Moreover, as a whole, the complex viscosity values of the blends are between those of two pure polymers and decrease with increasing F-PAEK content. However, at 50% weight fraction of PEEK, the viscosity-composition curves exhibit a local maximum, which may be mainly attributed to the phase separation of two components at such a composition. The changes of GЈ and GЉ with composition show a trend similar to that of complex viscosity.

Dynamic rheological behavior of poly(ether ketone ketone) from solid state to melt state

“…For isotherms above melting, shear viscosity behavior was plotted as a function of shear rate from 1 to 400 rad s −1 (Figure ). From 10 2 rad s −1 , the observed viscosity decreases: This is consistent with a rheofluidifying behavior which is classical for linear polymers . For low shear rate at 355 °C, the constant value corresponding to the zero shear‐rate viscosity η 0 is 710 Pa s.…”

“…Few studies were devoted to high performance thermoplastics in the molten state; Chen et al . investigated the evolution of viscosity and shear modulus for blend PEEK and liquid PEAK.…”

“…Few studies were devoted to high performance thermoplastics in the molten state; Chen et al 10 investigated the evolution of viscosity and shear modulus for blend PEEK and liquid PEAK. Lamethe 11 reported the effect of the temperature on PEEK viscosity for structural sticking applications while Guehenec et al 12 considered PEEK filled with carbon nanotubes to study the nanocomposite viscosity.…”

“…Various configurations of melt polymer rheology have been explored: semi-hyperbolic die channel system (Collier et al 15 ), cone-plate 13 , and plate-plate configuration. [10][11][12]16 In this work, a parallel plate configuration is proposed. Master curves have already been built for technical polymers; for example Yin and Ferry 17 have investigated rheological behaviors of poly(ethyl butyl methacrylate) with various chain lengths and molecular weights.…”

Synthesis of Wholly Aromatic Polyketones

“…53,54 Aromatic copoly(ether ketone)s showing LCP property were also reported. 55,56 Several synthetic approaches with the aid of direct condensation agent 57 or superacidmediated reaction 58,59 and those by utilization of specially structured compounds [60][61][62] were also reported. Contrary to the aromatic poly(ether ketone)s described above, there have been scarcely reported synthesis and characterization of wholly aromatic polyketones.…”