DOI: 10.5061/dryad.jh9w0vtn3
title: Telechelic dithiol copolymers as tunable building blocks for synthesizing multiblock materials

description: A new strategy is reported to access α,ω‐dithiol polymer building blocks
 with tunable molecular weights and compositions for the preparation of
 random multiblock copolymers based on styrenic, acrylic, and siloxanes.
 This facile synthetic approach provides access to dithiols through a
 two‐step process: (1) an initial copolymerization of vinyl monomers with
 ethyl lipoate followed by (2) disulfide bond reduction, producing dithiol
 terminated polymer products. Thiol‐terminated polymers are easily prepared
 over a wide range of molecular weights (2–32 kDa) by simply controlling
 the feed ratio of vinyl monomer to ethyl lipoate. Mixtures of these linear
 dithiol‐terminated building blocks were repolymerized via oxidative
 coupling to create random multiblock copolymers with high molecular
 weights (68–95 kDa) and controlled degradability. In summary, this
 approach for preparing and recombining telechelic dithiol polymers creates
 opportunities to manipulate the mechanical and physical properties of
 multiblock copolymers using a synthetically simple and versatile platform.
description: Characterization methods <em>1H nuclear
 magnetic resonance (NMR) spectroscopy</em>
  1H-NMR spectra were collected on a Bruker Avance NEO 500 MHz at
 25 °C using chloroform-d as a deuterated solvent.
 <em>Size-exclusion chromatography (SEC)
 instrumentation</em> Size-exclusion
 chromatography (SEC) was performed on a Waters instrument using a
 differential refractive index detector and two Tosoh columns (TSKgel
 SuperHZM-N, 3 μm polymer, 150 × 4.6 mm) with THF at 35 °C or chloroform
 containing 0.25% TEA at 35 °C for the mobile phase. Molar mass and molar
 mass dispersities (Đ) were determined against narrow PS standards
 (Agilent). <em>Differential scanning calorimetry
 (DSC)</em> DSC was performed on a TA Instruments
 Q2000 DSC with three repeated cycles between −150 and +150 °C at a
 constant rate of 10 °C/min. Only the second heating scan is
 shown. <em>Small-angle X-ray scattering
 (SAXS)</em> SAXS measurements were performed on a
 custom-built SAXS diffractometer housed at the University of California,
 Santa Barbara. The sample-to-detector distance was 1.7 m with a fixed
 wavelength of 1.54 Å. For all SAXS experiments, a silver behenate standard
 was used to calibrate the scattering angles. Two-dimensional (2D) data
 were reduced by azimuthal averaging to
 give <em>I</em>(<em>q</em>),
 where <em>I</em> is the intensity in arbitrary
 units, <em>q</em> = |<strong>q</strong>|
 =4πλ<sup>–1</sup> sin(θ/2) is the magnitude of the scattering
 wave vector, λ is the wavelength of the incident beam, and θ is the
 scattering angle. Two data points (at <em>q</em> = 0.15438 Å
 and <em>q</em> = 0.16026 Å), which correspond to two known
 dead pixels on the detector, were excised from the resulting data set for
 clarity. <em>Mechanical tensile
 testing</em> For uniaxial extension tensile
 tests, a Teflon dog bone mold was used to shape samples on a Carver press
 (Wabash, IN) 10 kPA at 160 °C for 10 min and then cooled (gauge depth =
 0.5 mm, gauge width = 1.5 mm, gauge length = 10 mm, transition zone radius
 = 2.5 mm). Uniaxial tensile testing was performed on a TA.XT Plus Connect
 Texture Analyzer with a 50N load cell using the Miniature Tensile grips
 (TA-96B) from the manufacturer. Grip surfaces were covered with adhesive
 backed foam padding to avoid damage to tensile bars and slip of samples
 from the grips. Samples were deformed at 0.1 mm/s until failure.
 Mechanical testing of polymer samples was performed in triplicate and
 representative data is included in the main text.
description: # Title of Dataset: Telechelic dithiol copolymers as tunable building
 blocks for synthesizing multiblock materials This deposit includes the
 data necessary to reproduce all figures in the associated manuscript,
 except for figures that consist of pictures or illustrations. Data is
 acquired from the following analytical characterization techniques:
 Characterization methods 1H nuclear magnetic resonance (NMR) spectroscopy
 1H-NMR spectra were collected on a Bruker Avance NEO 500 MHz at 25 °C
 using chloroform-d as a deuterated solvent. Size-exclusion chromatography
 (SEC) instrumentation Size-exclusion chromatography (SEC) was performed on
 a Waters instrument using a differential refractive index detector and two
 Tosoh columns (TSKgel SuperHZM-N, 3 μm polymer, 150 × 4.6 mm) with THF at
 35 °C or chloroform containing 0.25% TEA at 35 °C for the mobile phase.
 Molar mass and molar mass dispersities (Đ) were determined against narrow
 PS standards (Agilent). Differential scanning calorimetry (DSC) DSC was
 performed on a TA Instruments Q2000 DSC with three repeated cycles between
 −150 and +150 °C at a constant rate of 10 °C/min. Only the second heating
 scan is shown. Small-angle X-ray scattering (SAXS) SAXS measurements were
 performed on a custom-built SAXS diffractometer housed at the University
 of California, Santa Barbara. The sample-to-detector distance was 1.7 m
 with a fixed wavelength of 1.54 Å. For all SAXS experiments, a silver
 behenate standard was used to calibrate the scattering angles.
 Two-dimensional (2D) data were reduced by azimuthal averaging to give
 I(q), where I is the intensity in arbitrary units, q = |q| =4πλ–1 sin(θ/2)
 is the magnitude of the scattering wave vector, λ is the wavelength of the
 incident beam, and θ is the scattering angle. Two data points (at q =
 0.15438 Å and q = 0.16026 Å), which correspond to two known dead pixels on
 the detector, were excised from the resulting data set for clarity.
 Mechanical tensile testing For uniaxial extension tensile tests, a Teflon
 dog bone mold was used to shape samples on a Carver press (Wabash, IN) 10
 kPA at 160 °C for 10 min and then cooled (gauge depth = 0.5 mm, gauge
 width = 1.5 mm, gauge length = 10 mm, transition zone radius = 2.5 mm).
 Uniaxial tensile testing was performed on a TA.XT Plus Connect Texture
 Analyzer with a 50N load cell using the Miniature Tensile grips (TA-96B)
 from the manufacturer. Grip surfaces were covered with adhesive backed
 foam padding to avoid damage to tensile bars and slip of samples from the
 grips. Samples were deformed at 0.1 mm/s until failure. Mechanical testing
 of polymer samples was performed in triplicate and representative data is
 included in the main text. \## Description of the data and file structure
 Data files are organized into folders. Main text manuscript figures which
 are numbered according to the figure then further divided into each
 individual trace. All data can be opened as a .csv or .txt files using a
 text editor or a spreadsheet program.  Data files are organized as
 follows: MainTextFigures -&gt; Figure number -&gt; figure sub-category (a,
 b, c, etc.) -&gt; trace For figures with multiple traces on a single graph
 the traces are numbered reading top to bottom left to right or titled as
 given by the legend on the figure itself. For Example: Figure 2 has two
 graphs with 3 traces each. We start with the left graph, then read top to
 bottom. The data for the 32 kDa, 5 mol% ELP PS is found: MainTextFigures
 -&gt; Figure2 -&gt; Fig2a-PS5mol_pct.txt Figure 2 has two graphs with 3
 traces each. We start with the left graph, then read top to bottom. The
 data for the 11 kDa, 40 mol% ELP PnBA is found: MainTextFigures -&gt;
 Figure2 -&gt; Fig2e-PnBA40mol_pct.txt All data is supplied in two columns
 (x,y) these columns refer to the x and y axis on each graph. Refer to the
 manuscript and to the original graph for appropriate legends. All SEC data
 supplied is normalized to the peak being analyzed. Figures 2 and 4 display
 size-exclusion chromatography (SEC) data, and Figure 6 illustrates
 uniaxial tension (UAT) measurements.