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Title: “Uncontrolled” Preparation of Disperse Poly(lactide)- block -poly(styrene)- block -poly(lactide) for Nanopatterning Applications

Journal Article · · Macromolecules

We report the facile synthesis of well-defined ABA poly(lactide)-block-poly(styrene)-block-poly(lactide) (LSL) triblock copolymers having a disperse poly(styrene) midblock (Ð = 1.27–2.24). The direct synthesis of telechelic α,ω-hydroxypoly(styrene) (HO-PS-OH) midblocks was achieved using a commercially available difunctional free radical diazo initiator 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide]. Poly(lactide) (PLA) end blocks were subsequently grown from HO-PS-OH macroinitiators via ring-opening transesterification polymerization of (±)-lactide using the most common and prevalent catalyst system available, tin(II) 2-ethylhexanoate. Fourteen LSL triblock copolymers with total molar masses Mn,total = 24–181 kg/mol and PLA volume fractions fPLA = 0.15–0.68 were synthesized and thoroughly characterized. The self-assembly of symmetric triblocks was analyzed in the bulk using small-angle X-ray scattering and in thin films using grazing incidence small-angle X-ray scattering and atomic force microscopy. We demonstrate both the bulk and thin film self-assembly of LSL disperse triblocks gave well-organized nanostructures with uniform domain sizes suitable for nanopatterning applications.

Research Organization:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Organization:
National Science Foundation (NSF)
OSTI ID:
1351389
Journal Information:
Macromolecules, Vol. 49, Issue 21; ISSN 0024-9297
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
ENGLISH