Journal of Applied Polymer Science, Vol.109, No.6, 3659-3664, 2008
Self-organized MEH-PPV domains in a TPU matrix and the consequences to the luminescence spectra
Self-sustained cast films formed from heterogeneous blends of poly(2-methoxy-5-(2'-ethyl-hexyloxy)1,4-phenylenevinylene) (MEH-PPV) conjugated polymer and thermoplastic polyurethane (TPU) were investigated by photoluminescence (PL) and scanning electron microscopy (SEM). A blue shift is observed for the pure electronic transition PL peak (E-00) with decreasing MEH-PPV concentration. The two clear shoulders in the PL spectra at higher energy than the E-00 peak appear due to the formation of small conjugation segments of the MEH-PPV molecules at the interface of the spherical MEH-PPV domains. This assumption and the origin of the blue shift were confirmed by correlating the average size of the MEH-PPV domains, observed from SEM images, and the analysis of the PL spectra at low temperatures. (c) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 109: 3659-3664, 2008.
Keywords:conjugated polymer;optical properties;polymer blend;scanning electron microscopy;thermoplastic polyurethane