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. 2012 Apr 3;1(4):519-523.
doi: 10.1021/mz3000804.

Design and Synthesis of Network-Forming Triblock Copolymers Using Tapered Block Interfaces

Wei-Fan Kuan  1 , Raghunath Roy, Lixia Rong, Benjamin S Hsiao, Thomas H Epps 3rd
Affiliations

Design and Synthesis of Network-Forming Triblock Copolymers Using Tapered Block Interfaces

Wei-Fan Kuan et al. ACS Macro Lett. .

Abstract

We report a strategy for generating novel dual-tapered poly(isoprene-b-isoprene/styrene-b-styrene-b-styrene/methyl methacrylate-b-methyl methacrylate) [P(I-IS-S-SM-M)] triblock copolymers that combines anionic polymerization, atom transfer radical polymerization (ATRP), and Huisgen 1,3-dipolar cycloaddition click chemistry. The tapered interfaces between blocks were synthesized via a semi-batch feed using programmable syringe pumps. This strategy allows us to manipulate the transition region between copolymer blocks in triblock copolymers providing control over the interfacial interactions in our nanoscale phase-separated materials independent of molecular weight and block constituents. Additionally, we show the ability to retain a desirous and complex multiply-continuous network structure (alternating gyroid) in our dual-tapered triblock material.

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Figures

Figure 1
Figure 1
Theoretical prediction (dash line) and experimental data (solid dot) for the overall PMMA mole fraction changes versus reaction time in the ATRP of SM tapered segment.
Figure 2
Figure 2
Representative Gel Permeation Chromatography data for the P(SM) tapered segment (purple), P(SM-M) tapered copolymer (blue), P(I-IS-S) tapered diblock copolymer (red), and P(I-IS-S-SM-M) tapered triblock copolymer (green). The number average molecular weights and polydispersity indices of TBCs were determined using a Viscotek 270Max instrument fitted with Waters Styragel HR1 and HR4 columns in series, operated with THF as the mobile phase, and calibrated using polystyrene standards.
Figure 3
Figure 3
SAXS profile at 30 °C for P(I-IS-S-SM-M). From the primary peak position, the domain spacing was 44 nm, and the peaks were indexed according to I4132 symmetry, characteristic of the alternating gyroid (Q214) morphology.
Figure 4
Figure 4
TEM micrographs and TEMT image for P(I-IS-S-SM-M). (a) and (b) Experimental TEM images, representing the reflection planes [111] and [001], respectively. The inset images are simulated TEM micrographs from Epps et al. Dark domains correspond to OsO4-stained PI. Scale bars represent 50 nm. (c) 3-D reconstructed image. Only PI (blue) and PMMA (green) domains are shown for clarity. Scale bar represents 30 nm.
Scheme 1
Scheme 1
Schematic illustration of the P(I-IS-S-SM-M) synthesis using a combination of anionic polymerization, ATRP, and Huisgen 1, 3-dipolar cycloaddition click chemistry. The bottom image shows the density profile along a polymer chain and the composition profile along the TBC backbone.
See this image and copyright information in PMC

References

    1. Meuler AJ, Hillmyer MA, Bates FS. Macromolecules. 2009;42:7221–7250.
    1. Wohlgemuth M, Yufa N, Hoffman J, Thomas EL. Macromolecules. 2001;34:6083–6089.
    1. Crossland EJW, Kamperman M, Nedelcu M, Ducati C, Wiesner U, Smilgies DM, Toombes GES, Hillmyer MA, Ludwigs S, Steiner U, Snaith HJ. Nano Letters. 2008;9:2807–2812. - PubMed
    1. Crossland EJW, Nedelcu M, Ducati C, Ludwigs S, Hillmyer MA, Steiner U, Snaith HJ. Nano Letters. 2008;9:2813–2819. - PubMed
    1. Guo F, Schulte L, Zhang W, Vigild ME, Ndoni S, Chen J. Polymer Chemistry. 2011;2:553–555.