• Jesberger, Martin
• Davis, Thomas P.
• Malmström, Eva
• Stenzel, Martina H.

Abstract

<p>Polydisperse hyperbranched polyesters were modified for use as novel multifunctional reversible addition-fragmentation chain-transfer (RAFT) agents. The polyester-core-based RAFT agents were subsequently employed to synthesize star polymers of n-butyl acrylate and styrene with low polydispersity (polydispersity index &lt; 1.3) in a living free-radical process. Although the polyester-core-based RAFT agent mediated polymerization of n-butyl acrylate displayed a linear evolution of the number-average molecular weight (M_n) up to high monomer conversions (&gt;70%) and molecular weights [M_n &gt; 140,000 g mol^-1, linear poly(methyl methacrylate) equivalents)], the corresponding styrene-based system reached a maximum molecular weight at low conversions (≈30%, M_n = 45,500 g mol^-1, linear polystyrene equivalents). The resulting star polymers were subsequently used as platforms for the preparation of star block copolymers of styrene and n-butyl acrylate with a polyester core with low polydispersities (polydispersity index &lt; 1.25). The generated polystyrene-based star polymers were successfully cast into highly regular honeycomb-structured microarrays.</p>

Topics

• molecular weight
• copolymer
• block copolymer
• polydispersity