| Abstract: | The aim of this study was to introduce a new method for determining the surface composition and surface order of PP/EPDM (propylene/ethylene–diene–monomer rubber) blends, based on surface-enhanced infrared spectroscopy. PP/EPDM blends were characterized by Fourier transfer IR–attentuated total reflectance (FTIR-ATR) using two different internal reflection elements, Ge and KRS-5. These elements provide information at different depths and show differences in relative band intensities. A linear relationship between the ratio of the bands at 2850 and 2920 cm?1 EPDM content was obtained when well-defined compositions of PP and EPDM mixtures were used. Changes in crystallinity were measured by the ratio of the bands at 2959 and 2951 cm?1. For comparison, bands in the lower region of the spectrum and DSC and WAXS measurments were used. It was shown by two calibration methods that FTIR-ATR can provide information on surface composition and surface crystallinity at very low penetration depths. This new method indicates that injection-molded sample show a lower surface order and lower EPDM content at the surface than is seen in bulk. © 1993 John Wiley & Sons, Inc. |
