Issue 13, 2015

Nucleobase-functionalized acrylic ABA triblock copolymers and supramolecular blends


Reversible addition-fragmentation chain transfer (RAFT) polymerization afforded the unprecedented synthesis of well-defined acrylic ABA triblock copolymers with nucleobase-functionalized external blocks and a central poly(n-butyl acrylate) (PnBA) block. Size exclusion chromatography (SEC) confirmed the molecular weight and molecular weight distribution of the central block. 1H NMR spectroscopy revealed the successful chain extension of the PnBA macro-chain transfer agent (CTA) using adenine or thymine-functionalized acrylic monomers. The acrylic monomer with a flexible spacer to the pendant nucleobases promoted intermolecular recognition of nucleobases and long range segmental motion of polymer main chains. The external block glass transition temperatures (Tg's) of thymine (T) and adenine (A) functionalized blocks were 52 °C and 76 °C, respectively. Thermomechanical and morphological analysis revealed the effect of processing conditions on self-assembly and microphase-separated morphology of nucleobase-functionalized ABA copolymers. Thymine and adenine-functionalized ABA triblocks formed a thermodynamically stable, hydrogen-bonded complex upon blending. The supramolecular blend exhibited a cylindrical microphase-separated morphology with an extended plateau window compared to the individual block copolymers. The complementary hydrogen bonding between adenine and thymine formed a thermally labile, physically crosslinked, network that exhibited enhanced mechanical performance with melt processability. Thus, these ABA nucleobase-functionalized block copolymers demonstrate potential as thermoplastic elastomers for hot melt adhesives and coatings.

Graphical abstract: Nucleobase-functionalized acrylic ABA triblock copolymers and supramolecular blends

Supplementary files

Article information

Article type
26 Dec 2014
29 Jan 2015
First published
30 Jan 2015
This article is Open Access
Creative Commons BY license

Polym. Chem., 2015,6, 2434-2444

Author version available

Nucleobase-functionalized acrylic ABA triblock copolymers and supramolecular blends

K. Zhang, M. Aiba, G. B. Fahs, A. G. Hudson, W. D. Chiang, R. B. Moore, M. Ueda and T. E. Long, Polym. Chem., 2015, 6, 2434 DOI: 10.1039/C4PY01798F

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