Incorporation of PPE in Lamellar Self-Assembled PS-<i>b</i>-P4VP(PDP) Supramolecules and PS-<i>b</i>-P4VP Diblock Copolymers

Abstract

Self-assembled blends of PS- b -P4VP(PDP) supramolecules, obtained by hydrogen bonding of pentadecylphenol (PDP) side chains to poly(4-vinylpyridine), and poly(2,6-dimethyl-1,4-diphenyl oxide) (PPE) were investigated by thermal analysis and small-angle X-ray scattering (SAXS) and compared with blends of PS- b -P4VP and PPE. Differential scanning calorimetry (DSC) measurements showed a single composition dependent T g of the PPE/PS layers for both systems, demonstrating that PPE is distributed throughout the PS layers. Furthermore, DSC showed that for the PPE/PS- b -P4VP(PDP) blends the presence of PDP is not restricted to the P4VP layers. Its partial presence in the PS-containing domains was confirmed by nuclear magnetic resonance (NMR) spectroscopy on PS−P4VP core−corona nanorods prepared from hexagonally self-assembled PS- b -P4VP(PDP) supramolecules. The results of the SAXS study on the dependence of the lamellar period of PPE/PS- b -P4VP blends on the amount of PPE were in excellent agreement with a theoretical model based on the Alexander−De Gennes approximation assuming a uniform distribution of PPE throughout the PS layers. For PPE/PS- b -P4VP(PDP) blends the dependence of the long period on the amount of PPE turned out to be somewhat stronger, which may be related to the supramolecular comb-shaped nature of the P4VP(PDP) blocks.