Solid-State NMR Characterization on the Molecular-Level Homogeneity in Lower Critical Solution Temparature Mixtures of Poly(α-methyl styrene) and Poly(2,6-dimethyl-p-phenylene oxide)

Abstract

ABSTRACT:The length scale of heterogeneity in blends of poly(2,6-dimethyl-p-phenylene oxide) (PPO) with poly(α-methyl styrene) (PαMS) was investigated using solid state 13 C NMR. The PPO/PαMS blend system was homogeneous at ambient, but phase separation at or above the lower critical solution temperature (LCST) was confirmed by polarized-light microscopy (PLM) and differential scanning calorimetry (DSC). Fourier-transform infrared spectroscopy (FT-IR) characterization confirmed that there was no specific interaction between PPO and PαMS. The scales of homogeneity in the blend were examined.

Studies of Formation Mechanism, Structure, and Properties of Network Copolymers Obtained by Cocuring of Rolivsan Thermosetting Resins with Aromatic Diamines

“…Assignment of chemical shifts in the spectra of neat ROLs and ROL-ADA blends was consistent with the previously reported data [17][18][19][20][21][22][23][24]. These data are related to 13 C atoms included in kindred structures (groups, units, or segments).…”

“…In order to clarify this point, we analyzed other signals that could serve as indirect confirmation of chemical interactions (appearance of C-m and C-q and/or C-n and C-p signals, see scheme in Figure 7). Indeed, all spectra contain the most intense signal at 128-129 ppm that can be attributed both to 13 С Ar -H [19,[21][22][23] and to C-p (i.e., to 13 С Ar -N-C=O) [23,25]. There is also a signal appearing at…”