**Author details**

298 Viscoelasticity – From Theory to Biological Applications

experimentally measured flow curves are obtained.

different stages in capillary die at 190 oC.

**5. Conclusions** 

retain the orientation.

lower yielding shear rates for these blends, dynamic frequency sweep data performed on ARES were used combined with data from CR for simulation. The flow curves in Region (II) were obtained using the velocity profiles together with the power-law parameters in Regions (I) and (III). Figure 22 shows the schematic drawing of apparent shear viscosity as a function of shear stress at wall at the different stages in capillary die. Precise flow curves with Matlab program simulation for the blends are plotted in Figure 15 together with experimental data. Excellent agreement between the model prediction and the

**Figure 22.** Schematic drawing of apparent shear viscosity evolution as a function of stress at wall at

An organoclay-modified TLCP nanocomposite (TC3 white) with the organoclays of uniform size 15-25 nm in length well dispersed in thermotropic liquid crystalline polymer (TLCP) with fully exfoliated structures was designed and prepared by a combination method. Polarized optical microscope images showed that the organoclay did not affect the liquid crystallinity and mesophase structures of the TLCP matrix. However, thermal stability and thermal properties were affected by the organoclay, enhancing the thermal stability of TLCP and shifting the transition temperatures to the high ends. The presence of organoclays caused the nanocomposite to present different rheological behaviours with TLCP at the nematic temperature, i.e. 185 oC. Dynamic experiments demonstrated that TC3 white displayed higher pseudo-solidlike behaviour than TLCP alone in the low frequency region. TC3 white had a similar but even lower viscosity and the first normal stress difference (N1) than TLCP, but the rate of N1 increase in TC3 white was greater than that in TLCP. When enhanced with organoclays, TLCP became more rigid, and with a slight deformation in the TC3 white melt, organoclay helped the TLCP molecules to align in the shear direction and to

The rheological behaviours of purified TLCP and TC3 white in high molecular mass polyethylene (HMMPE) were characterized by capillary rheometer (CR) with nominal dies of L/D = 30 and diameters 0.7 mm and 1.0 mm at 190 oC, where purified TLCP and TC3 white showed similar nematic phase structures. At 230 oC, purified TLCP presented as a continuous isotropic phase with a minority of discrete nematic phase, whereas TC3 white Youhong Tang *Flinders University, Adelaide, South Australia, Australia* 

Ping Gao *The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China* 
