We report a reactive polymer platform for the rapid discovery of strongly segregated diblock polymers that microphase separate into well-defined morphologies with sub-5 nm features. Our strategy employs reactive poly(styrene-block-2-vinyl-4,4-dimethylazlactone) (SV) polymers with low degrees of polymerization (N), in which the V blocks undergo selective and quantitative reactions with functional primary amines, to identify new poly(acrylamides) that are highly immiscible with poly(styrene) and induce block polymer self-assembly. Using a combination of optical birefringence and small-angle X-ray scattering (SAXS), we characterize a library of 17 block polymers produced by amine functionalization of four parent SV diblocks synthesized by sequential RAFT polymerizations. We demonstrate that V block functionalization with hydroxy- and methoxy-functional amines yields diblocks that order into lamellar mesophases with half-pitches as small as 3.8 nm. Thus, this azlactone-based reactive molecular platform enables combinatorial generation of polymer libraries with diverse side chain structures that may be rapidly screened to identify new high χ/low N systems for self-assembly at ever decreasing length scales.
Bibliographical noteFunding Information:
This work was supported by the U.S. National Science Foundation Nanoscale Science and Engineering Center at UW-Madison (DMR-0832760) and made use of NSFsupported facilities (DMR-0832760, DMR-1121288 and CHE-1048642)
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