Small-Angle Scattering Investigations of Crystalline Blend Morphologies of Poly (E-Caprolactone) (PCL)/Polycarbonate (PC) Blends

Abstract

ABSTRACTCrystalline Morphologies of poly (e-caprolactone) (PCL) and deuterated polycarbonate (PC) blends in both the semicrystalline/amorphous state and semicrystalline/semicrystalline state were probed by small-angle neutron and X-ray scattering (SANS and SAXS). Due to the different contrast between the phases for neutrons and X-rays, SANS exhibited a monotonie drop in intensity with increasing scattering angle while SAXS showed lamellar (peak) scattering.Crystal- and amorphous-phase thickness were determined from the correlation function calculated from SAXS. This correlation function analysis suggested a transition from interlamellar exclusion to interlamellar incorporation of amorphous PCL in the PC lamellae. A two-correlation length model provided an excellent fit for the SANS data over the entire composition range. This Model not only reproduced the shape but also the absolute magnitude of the scattering profiles. The long range correlation length (∼102 Å) and the short range correlation length (∼ 10 Å) derived from this model were inferred to be associated with the crystalline PC domains and the local clusters found in the amorphous phase, respectively.