Synthesis, structure, and property of well-defined polymethylene-based diblock copolymers by a combination of living polymerization of ylides and atom transfer radical polymerization

Abstract

A combination of living polymerization of ylides and atom transfer radical polymerization (ATRP) was used successfully in the design and synthesis of well-defined polymethylene-b-poly(methyl methacrylate) (PM-b-PMMA) and polymethylene-b-poly(n-butyl acrylate) (PM-b-Pn-BuA). Tripolymethylene borane were firstly synthesized by living polymerization of dimethylsulfoxonium methylides and then oxidated quantitatively through trimethylamine-N-oxide dihydrate to provide a series of low-polydispersity hydroxyl-terminated polymethylenes (PM-OHs) with different molecular weight. Subsequently, such polymers were converted into polymethylene-based macroinitiators (PM-MIs, Mn(GPC) = 1900–10,400 g/mol; Mw/Mn = 1.12–1.23) in ∼100% conversion. ATRPs of methyl methacrylate and n-butyl acrylate were successfully conducted using PM-MI to produce well-defined diblock copolymers of PM-b-PMMA and PM-b-Pn-BuA, respectively. The GPC traces indicated the successful extension of PMMA and Pn-BuA segment (Mn(GPC) of PM-b-PMMA = 3980–10,100 g/mol; Mw/Mn = 1.16–1.22; Mn of PM-b-Pn-BuA = 7400–9200 g/mol; Mw/Mn = 1.14–1.18). Atomic force microscopy (AFM) was used to characterize the structures of the precipitated PM-b-PMMA micelles, which were formed in toluene. The blend of LDPE/PMMA was prepared with PM-b-PMMA as compatibilizer. The scanning electron microscopy (SEM) results showed that the compatibilization of the LDPE/PMMA was improved greatly by the incorporation of PM-b-PMMA. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5671–5681, 2009