Structure development during flow of polyblends containing liquid crystalline polymers

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Abstract
The microstructure development during capillary flow of polyblends containing Liquid Crystalline Polymers (LCPs) was studied. In the present investigation the wholly aromatic LCP constituent was the minor phase suspended in polycarbonate (PC), poly(butyleneterephthalate) (PBT) or Nylon 6 (N‐6), in addition to previously studied amorphous nylon matrix Experimental results showed that the viscous forces acting at the components' interface are predominating the elongational deformation and the resulting structure development of the LCP phase. In cases where the viscosity of the suspending matrix was higher than the LCP one (PC, amorphous nylon) scanning electron micrographs indicated that fibrillar structure developed. In cases where the viscosity of the matrix polymers was lower than the LCP suspended phase, fibrous structures developed only at very high shear rates. Due to velocity rearrangement effects at the capillary exit a skin core morphology was observed. Since the polymers viscosity depends both on shear rate and temperature, the in situ composite structure development depends on the specific processing methods and conditions that the LCP containing polyblends experience.