Influence of Annealing on Structure of Nylon 11

Abstract

Differential scanning calorimeter (DSC), wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), and density techniques have been used to investigate the structural parameters of the solid state of Nylon 11 annealed at different temperatures. The equilibrium heat of fusion Δ and equilibrium melting temperature were estimated to be 189.05 J g-1 and 202.85 °C respectively by using the Hoffman−Weeks approach. The degree of crystallinity (Wc,x) ranged approximately 24−42% was calculated by WAXD and compared with those by calorimetry (Wc,h) and density (Wc,d) measurements. The radius of gyration Rg, crystalline thickness Lc, noncrystalline thickness La, long period L, semiaxes of the particles (a, b), electron-density difference between the crystalline and noncrystalline regions ηc− ηa, and the invariant Q increased with increasing annealing temperature. The analysis of the SAXS data was based upon the particle characteristic function and the one-dimensional electron-density correlation funct...