Evidence of a transcrystalline interphase in fiber PE homocomposites as revealed by microdiffraction experiments using synchrotron radiation

Microbeam wide-angle X-ray scattering (WAXS) experiments have been carried out at different locations of a single-fiber PE homocomposite. The diffraction patterns reveal an oriented crystalline structure within a layer of 9 mum away from the fiber surface. This layer is associated with the occurrence of a transcrystalline interphase. The crystal structure appearing at the different locations of the composite material is predominantly orthorhombic. However, a small amount of a monoclinic phase was found to appear at the fiber skin and within the transcrystalline layer. The azimuthal scans of the two-dimensional (2D) WAXS patterns obtained at different sites of the transcrystalline phase were studied to estimate the crystal unit cell directions at each diffracted point. Finally, an analysis of the integral breadth of the (110) and (200) orthorhombic reflections in the matrix, in the trans crystalline interphase, and in the fiber is reported.