Abstract
Surface structure of polyethylene crystals is examined by small-angle X-ray scattering (SAXS). Folded chain crystals crystallized isothermally and extended chain crystals annealed isothermally showed SAXS obeying the Porod’s law in a range of scattering vector from 10−1.2 to 10−0.5 Å−1; the surfaces of these crystals are smooth above a scale of length of 20 Å. This result suggests that the thickening process of polymer crystals is controlled by nucleation and growth. Fractal surfaces reported previously are related with the fluctuation of driving force for the thickening; the fluctuation has power-law correlation in space or time.
