In situ composites formed by extrusion

The morphology, molecular orientation and ultrasonic moduli of extruded blends of polycarbonate (PC) and Vectra B have been studied by Choy et al [10]. We will denote these blends by PC + VBX where X is the weight percent of Vectra B in the blend. 

As we have seen, the structure of the in situ composites with low Vf is akin to that of a short fiber-reinforced composite. Lin and Yee [38] have proposed a two-step procedure for calculating the elastic moduli. First, the axial (E ) and transverse (E ) Young s moduli of the PLC domains in the composites are calculated in terms of the aggregate model. Then the axial Young s modulus of the composite can be 

Like our earlier calculation for the bulk PLC, E3 and E[ can be obtained using either the Voigt or Reuss averaging scheme. The aspect ratio L/D can be estimated assuming that the deformation is affine [26,38] i.e. the deformation of the PLC domains is identical to that of the 

We have mentioned that the PLC phase is continuous for Vf 0.55. At high draw ratio (A = 15), the PLC fibrils in PC - - VBlO and PC + VB30 are also essentially continuous, so the axial Young s modulus of all the composites can be analyzed in terms of the rule of mixtures valid for continuous fiber composites  

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