DOI: 10.5061/dryad.dr7sqvb49
title: Controlled radical polymerization of α-Lipoic acid: A general route to degradable vinyl copolymers

description: Here, we present the synthesis and characterization of statistical and
 block copolymers containing α-lipoic acid (LA) using reversible
 addition–fragmentation transfer (RAFT) polymerization. LA, a readily
 available nutritional supplement, undergoes efficient radical ring-opening
 copolymerization with vinyl monomers in a controlled manner with
 predictable molecular weights and low molar-mass dispersities. Because
 lipoic-acid diads present in the resulting copolymers include disulfide
 bonds, these copolymers efficiently and rapidly degrade when exposed to
 mild reducing agents such as tris(2-carboxyethyl)phosphine
 (Mn = 56 kg mol–1 → 3.6 kg mol–1). This scalable and versatile polymerization method affords a facile way to synthesize degradable polymers with controlled architectures, molecular weights, and molar-mass dispersities from α-lipoic acid, a commercially available and renewable monomer.
description: <em><sup>1</sup>H nuclear magnetic resonance
 spectroscopy</em> Solution state
 <sup>1</sup>H nuclear magnetic resonance (NMR) spectra were
 recorded on a Varian VNMRS 600 MHz spectrometer. Chemical shifts (δ) are
 reported in ppm relative to residual protio solvent in
 CDCl<sub>3</sub> (7.26 ppm).
 <em>Size-exclusion chromatography
 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 masses and molar
 mass dispersities (Đ) were determined against narrow PS standards
 (Agilent). <em>Dynamic Light Scattering
 (DLS)</em> The DLS experiment was performed with
 disposable 4 mL plastic cuvettes for the DLS instrument with 1 mL of
 aqueous solution. The light scattering signals were measured by using a
 Marvin Instrument Ltd. nanoZS Zetasizer.
 <em>Photoluminescence</em>
 Solution-state photoluminescent data were obtained using a
 Jobin-Yvon HORIBA FluoroMax-4 (xenon source, 1.0 nm excitation, and
 emission slit widths, 1 nm step size, λ<sub>excitation</sub> =
 536 nm) equipped with a solution-state sample holder and quartz cuvette
 with a diameter of 1 cm. Photoluminescent data were analyzed using the
 FluorEssence (v3.5) software powered by Origin. Samples were prepared
 according to the following: A stock solution of polymer (~2.2 mg) was
 dissolved in 100 µL of THF. The micelles were prepared by rapidly mixing
 the THF solution with 3 mL of Milli-Q water. With Nile red, a 1 µg/mL
 solution was added to the polymer THF solution prior to micelle
 formation.  <em>Thermal
 characterization</em> Thermogravimetric analysis
 (TGA) was performed under air on a TA Instruments Q500 at a heating rate
 of 10 °C min<sup>−1</sup> with a sample size of ca. 10 mg.
 Differential Scanning Calorimetry (DSC) was performed using a TA
 Instruments DSC Q2000 at a heating/cooling rate of 10 °C/min using 3–5 mg
 of sample in a sealed aluminum pan.
description: # Title of Dataset: Controlled Radical Polymerization of α-Lipoic Acid: A
 General Route to Degradable Vinyl Copolymers Data files are organized into
 one folder: with the manuscript and supporting information. This folder is
 related to the publication which includes the manuscript and supporting
 information document. All data can be opened as a .csv file using Excel or
 google sheets(free alternative) Data files are organized as follows:
 manuscript -&gt; Figure number -&gt; figure sub-category Within
 each data file, there are tabs for each unique trace. The tab is denoted
 as the trace identifier. Some trace identifiers are label names, the
 unique color of the trace, or unique line style (e.g. dashed vs. solid
 lines) Compounds are denoted as such: Lipoic acid (LA), Dodecyl acrylate
 (DA), trifluoro ethyl acrylate (TFA), poly[(trifluoroethyl
 acrylate–co–α-lipoic acid)–block–dodecyl acrylate](TFA-co-LA),
 poly[(trifluoroethyl acrylate–co–α-lipoic acid)–block–dodecyl
 acrylate]((TFA-co-LA)-b-DA), poly(ethylene glycol) (PEG) For Example: SEC
 trace in Figure S6 for the degraded 10% LA sample will be categorized as
 follows: Figure-4 -&gt; tab-10% LA degraded The blue trace in the left
 graph in Figure 5 will be categorized as follows: Figure-5 -&gt;
 tab-left blue Figures that are pictures and illustrations will not be
 included in the folders. This includes Figure 1, Figure 2a,c, and Figures
 7a and b. All data is supplied in two columns (x,y) these columns refer to
 the x and y axis on each graph. Please refer to the manuscript and to the
 original graph for appropriate legends. All SEC data supplied is
 normalized to the peak being analyzed. ## Description of the Data and file
 structure The following describes Figure X; The parameters used for each
 figure are listed at the end. 2c:NMR 3a: conversion plot 3b: conversion
 plot 4: SEC 8:SEC 6:SEC 7c:Photoluminescence S1:NMR S2:SEC S3:SEC S4:SEC
 S5:SEC S6:SEC S7:SEC S8:SEC S9:Conversion plots S10:SEC S11:SEC S12:SEC
 S13:SEC S14:SEC S15:SEC S17:NMR S18:DSC S19:TGA S20:NMR S21:SEC S22:NMR
 S23:SEC S24:NMR S25:NMR S26:NMR S27:SEC S28:NMR S29:SEC S30:SEC 1H nuclear
 magnetic resonance spectroscopy Solution state 1H nuclear magnetic
 resonance (NMR) spectra were recorded on a Varian VNMRS 600 MHz
 spectrometer. Chemical shifts (δ) are reported in ppm relative to residual
 protio solvent in CDCl3 (7.26 ppm). Size-exclusion chromatography
 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 masses and molar mass dispersities (Đ) were determined against
 narrow PS standards (Agilent). Dynamic Light Scattering (DLS) The DLS
 experiment was performed with disposable 4 mL plastic cuvettes for the DLS
 instrument with 1 mL of aqueous solution. The light scattering signals
 were measured by using a Marvin Instrument Ltd. nanoZS Zetasizer.
 Photoluminescence Solution-state photoluminescent data were obtained using
 a Jobin-Yvon HORIBA FluoroMax-4 (xenon source, 1.0 nm excitation, and
 emission slit widths, 1 nm step size, λexcitation = 536 nm) equipped with
 a solution-state sample holder and quartz cuvette with a diameter of 1 cm.
 Photoluminescent data were analyzed using the FluorEssence (v3.5) software
 powered by Origin. Samples were prepared according to the following: A
 stock solution of polymer (\~2.2 mg) was dissolved in 100 µL of THF. The
 micelles were prepared by rapidly mixing the THF solution with 3 mL of
 Milli-Q water. With Nile red, a 1 µg/mL solution was added to the polymer
 THF solution prior to micelle formation. Thermal characterization
 Thermogravimetric analysis (TGA) was performed under air on a TA
 Instruments Q500 at a heating rate of 10 °C min−1 with a sample size of
 ca. 4 mg. Differential Scanning Calorimetry (DSC) was performed using a TA
 Instruments DSC Q2000 at a heating/cooling rate of 10 °C/min using 3–5 mg
 of sample in a sealed aluminum pan. ## Sharing/Access Information Links to
 other publicly accessible locations of the data: data is published as a
 peer-reviewed article in JACS.