DYNAMIC RHEOOPTICAL CHARACTERIZATION OF A LOW-DENSITY POLYETHYLENE PERDEUTERATED HIGH-DENSITY POLYETHYLENE BLEND BY 2-DIMENSIONAL STEP-SCANFTIR SPECTROSCOPY

Dynamic mechanical analysis coupled with polarized step-scan FTIR tran smission and two-dimensional correlation analysis (2D FTIR) has been u sed to monitor the submolecular orientational responses of the compone nts of a semicrystalline 50 : 50 blend of low-density polyethylene (LD PE) and perdeuterated high-density polyethylene (d-HDPE) to a small a mplitude uniaxial 23.47 Hz sinusoidal mechanical strain. Perdeuteratio n of the HDPE component allowed the distinction of its response from t hat of the LDPE in the blend samples. The experiments were carried out at room temperature. Analysis of the data indicates that the crystall ine parts of the two components reorient at different rates, with the functional groups of the high-density portion reorienting faster, in g eneral, than those of the LDPE in response to the mechanical strain. ( C) 1993 John Wiley & Sons, Inc.