Effect of iodine doping on the miscibility of poly(para-phenylene vinylene) model compounds mixed with PMMA using NMR solid-state techniques

Abstract

Chemical shift data of CP/MAS C-13 NMR spectra and T1(rho)H measurements as well as H-1 combined rotation and multiple pulse spectroscopy (CRAMPS) using 2D exchange experiments indicate that iodine doping of mixtures of trans,trans-1,4-bis(2-(3,4,5-trimethoxyphenyl)ethenyl)benzene (MPV) and poly(methyl methacrylate) (PMMA) induces heterogeneity. It is shown by 2D H-1 CRAMPS experiments that doped trans, trans-MPV mixtures with weight ratio MPV/PMMA/I2 = 1/1.5/1 are completely heterogeneous, whereas undoped MPV mixtures are homogeneous. Phase separation upon doping occurs also for the cis-tram mixtures of MPV.