Synthesis and analysis of phase segregation of polystyrene‐ block ‐poly(methyl methacrylate) copolymer obtained by Steglich esterification from semitelechelic blocks of polystyrene and poly(methyl methacrylate)

Here, an alternative route to successfully synthesize polystyrene‐ block ‐poly(methyl methacrylate) (PS‐ b ‐PMMA) is reported. Steglich esterification was used as an effective, metal free approach for coupling carboxylic terminated PS and the hydroxyl end‐functionalized PMMA chains obtained by nitroxide‐mediated polymerization and atom transfer radical polymerization, respectively. α‐Functionalization was obtained using 4,4′‐azobis(4‐cyanovaleric acid) and 2,2,2‐tribromoethanol as initiators. The synthesis of PS‐ b ‐PMMA was confirmed by gel permeation chromatography and nuclear magnetic resonance (NMR), while the dependence of the diffusion coefficients of the polymers (PS, PMMA, PS/PMMA blend, and PS‐ b ‐PMMA) with their corresponding molecular weights was discussed based on the results of atomic force microscopy‐based infrared spectroscopy, differential scanning calorimetry, and spectra of diffusion‐ordered NMR spectroscopy. Differently from PS‐ b ‐PMMA, a partial segregation was observed for the PS/PMMA blend, affecting its thermal behavior and diffusion coefficient. The study here presented provides an easier and efficient strategy for the synthesis of PS‐ b ‐PMMA and new insights into the diffusion of polymers.