DOI: 10.5061/dryad.9s4mw6ms2
title: Carbosiloxane Bottlebrush Networks for Enhanced Performance and Recyclability

description: Silicone bottlebrush copolymers and networks derived from cyclic
 carbosiloxanes are reported and shown to have enhanced properties and
 recyclability compared to traditional dimethylsilxoane-based materials.
 The preparation of these materials is enabled by the synthesis of
 well-defined heterotelechelic macromonomers with Si–H and norbornene chain
 ends via anionic ring-opening polymerization of the hybrid carbosiloxane
 monomer 2,2,5,5-tetramethyl-2,5-disila-1-oxacyclopentane. These novel
 heterotelechelic α-Si–H/ω-norbornene macromonomers undergo efficient
 ring-opening metathesis copolymerization to yield functional bottlebrush
 polymers with accurate control over molecular weight and functional-group
 density. Si–H groups retained at the ends of side-chains after
 ring-opening metathesis copolymerization allow for the preparation of
 super-soft networks via hydrosilylation with crosslinkers such as
 tetrakis[dimethyl(vinyl)silyl]orthosilicate. In contrast to traditional
 PDMS systems, the incorporation of poly(carbosiloxane) side chains allows
 the resulting networks to be recycled back to the original monomer
 (&gt;85% recovery) via depolymerization at elevated temperatures (250
 °C) in the presence of base catalysts (potassium hydroxide and
 tetramethylammonium hydroxide). Recovered monomer was successfully
 repolymerized through anionic ring-opening polymerization with no decrease
 in structural fidelity or activity. In summary, this combination of unique
 (macro)monomer design and bottlebrush architecture creates new
 opportunities in sustainable practices by offering a robust, recyclable
 alternative to commercial silicone-based materials.
description: Chemical Characterization
 <sup>1</sup>H, <sup>13</sup>C and
 <sup>29</sup>Si nuclear magnetic resonance (NMR) spectra were
 recorded on a Bruker Avance NEO 500 MHz spectrometer, using
 CDCl<sub>3</sub> as the solvents. Size-exclusion
 chromatography (SEC) was measured using Waters e2695 separation module
 with a Waters 2414 differential refractive index detector equipped with
 two columns (Tosoh TSKgel SuperHZM-N 3 μm polymer, 150 × 4.6 mm) with THF
 at 35 °C as the mobile phase. Molecular weights and dispersities
 (<em>Đ</em>) were determined against narrow polystyrene
 standards (Agilent). Bruker Microflex LRF MALDI TOF mass spectrometer in
 positive reflection mode; the analyte, matrix (DCTB) were dissolved in THF
 at the concentration of 2.5 and 10 mg/mL respectively, and cationization
 agent (NaI) was dissolved in THF at concentrations of 1 mg/mL, then mixed
 in a volume ratio of 20 : 1 : 1 (DCTB : NaI : sample). 0.5 μL of this
 mixed solution was spotted onto a ground steel target plate and the
 solvent was allowed to evaporate prior to analysis. Gas
 chromatography–high-resolution mass spectrometry (GC-HRMS) was carried out
 on a JMS-700 from JEOL in FAB mode. Thermogravimetric analysis (TGA) was
 performed under N<sub>2</sub> on a TA Instruments Q500 at a
 heating rate of 10 °C/min. Differential Scanning Calorimetry (DSC) was
 performed using a TA Instruments DSC 2500 at a heating/cooling rate of 10
 °C/min with a sealed aluminum pan. Rheology
 Rheology experiments were performed on a strain-controlled TA
 Instruments ARES-G2 rheometer affixed with a forced convection oven (FCO)
 in a nitrogen atmosphere. 8 mm sample pucks were punched out of square
 molds. Frequency sweeps were performed from high to low frequency at room
 temperature and 3% strain, which was confirmed to be in the linear
 viscoelastic regime via amplitude sweeps. The curing profile (Figure S16)
 was obtained by performing a time sweep for 10 minutes at room
 temperature, 1000% strain, and a frequency of 1 rad/s; a temperature sweep
 from room temperature to 100 °C at a ramp rate of 30 °C/min, 1000% strain,
 and a frequency of 1 rad/s; and, finally, a time sweep for approximately 6
 hours at 100 °C, 1% strain, and a frequency of 1 rad/s.
description: # Carbosiloxane Bottlebrush Networks for Enhanced Performance and
 Recyclability
 [https://doi.org/10.5061/dryad.9s4mw6ms2](https://doi.org/10.5061/dryad.9s4mw6ms2) This dataset provides tabulated values for all the plots featured in the associated manuscript, including nuclear magnetic resonance (NMR) spectroscopy, size-exclusion chromatography (SEC), matrix-assisted laser desorption ionization-time of flight (MALDI-TOF), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) data. The dataset is separated into two primary folders, each containing subfolders corresponding to each manuscript figure from the main text or supplementary information. ## Description of the data and file structure This dataset is separated into two primary folders—Maintext and SupplementaryInformation. Each primary folder contains subfolders corresponding to a Figure. Each of these subfolders contains one or more Excel files with the data in that Figure. If multiple datasets appear in a single Figure, datasets are separated onto separate worksheets with the names of the worksheets bearing the sample identification. For all datasets, the X-axis data appears in Column 1 while Y-axis data appears in subsequent columns. In the descriptions below, units are included in brackets. ## List and Description of Files ###### Maintext **Figure2.** SEC traces of bottlebrush copolymers with different backbone lengths and their precursors. Each sample arranged on different worksheets. Column 1: retention time [minutes]. Column 2: normalized refractive index [arbitrary]. **Figure3.** Rheological curing profile of a bottlebrush network. Column 1: time [hours]. Column 2: storage modulus [kPa]. Column 3: loss modulus [kPa]. **Figure4.** Frequency sweeps of bottlebrush networks with different backbone lengths. Each sample arranged on different worksheets. Column 1: frequency [rad/s]. Column 2: storage modulus [kPa]. ###### SupplementaryInformation **FigureS1.** H NMR of H-Si macromonomer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS2.** C NMR of H-Si macromonomer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS3.** Si NMR of H-Si macromonomer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS4.** H NMR of Bu macromonomer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS5.** C NMR of Bu macromonomer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS6.** Si NMR of Bu macromonomer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS7a.** SEC traces of H-Si macromonomer. Each sample arranged on different worksheets. Column 1: retention time [minutes]. Column 2: Normalized refractive index [arbitrary]. **FigureS07b.** SEC traces of Bu macromonomer. Each sample arranged on different worksheets. Column 1: retention time [minutes]. Column 2: Normalized refractive index [arbitrary]. **FigureS8.** MALDI-TOF spectra for both macromonomers. Each sample arranged on different worksheets. Column 1: mass to charge ratio [arbitrary]. Column 2: Normalized intensity [arbitrary]. **FigureS9.** H NMR of bottlebrush copolymer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS10.** C NMR of bottlebrush copolymer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS11.** Si NMR of bottlebrush copolymer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS12.** SEC traces of bottlebrush copolymers with different backbone lengths and their precursors. Each sample arranged on different worksheets. Column 1: retention time [minutes]. Column 2: normalized refractive index [arbitrary]. **FigureS13a.** SEC traces of bottlebrush copolymer with longer side chains and its precursors. Each sample arranged on different worksheets. Column 1: retention time [minutes]. Column 2: Normalized refractive index [arbitrary]. **FigureS13b.** SEC traces of bottlebrush copolymer with shorter side chains and its precursors. Each sample arranged on different worksheets. Column 1: retention time [minutes]. Column 2: Normalized refractive index [arbitrary]. **FigureS14.** H NMR of bottlebrush copolymers with different amounts of cross-linking sites. Each sample arranged on different worksheets. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS15.** SEC traces of bottlebrush copolymers with different amounts of cross-linking sites. Each sample arranged on different worksheets. Column 1: retention time [minutes]. Column 2: Normalized refractive index [arbitrary]. **FigureS16.** TGA traces of linear polymer, bottlebrush copolymer, and network. Each sample arranged on different worksheets. Column 1: temperature [°C]. Column 2: weight percent [%]. Column 3: derivative of weight percent [%/°C]. **FigureS17.** DSC traces of linear polymer, bottlebrush copolymer, and network. Each sample arranged on different worksheets. Column 1: temperature [°C]. Column 2: normalized heat flow [W/g]. **FigureS18.** Rheological curing profile of a bottlebrush network. Column 1: time [hours]. Column 2: storage modulus [kPa]. Column 3: loss modulus [kPa]. **FigureS19.** Frequency sweeps of bottlebrush networks with different backbone lengths. Each sample arranged on different worksheets. Column 1: frequency [rad/s]. Column 2: storage modulus [kPa]. Column 3: loss modulus [kPa]. **FigureS20.** Frequency sweeps of bottlebrush networks with different amounts of cross-linking. Each sample arranged on different worksheets. Column 1: frequency [rad/s]. Column 2: storage modulus [kPa]. Column 3: loss modulus [kPa]. **FigureS21.** Frequency sweeps of bottlebrush networks with different side chain lengths. Each sample arranged on different worksheets. Column 1: frequency [rad/s]. Column 2: storage modulus [kPa]. Column 3: loss modulus [kPa]. **FigureS22.** H NMR of polydimethylsiloxane H-Si macromonomer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS23.** H NMR of polydimethylsiloxane Bu macromonomer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS24.** H NMR of polydimethylsiloxane bottlebrush copolymer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS25.** SEC traces of polydimethylsiloxane bottlebrush copolymer and its precursors. Each sample arranged on different worksheets. Column 1: retention time [minutes]. Column 2: normalized refractive index [arbitrary]. **FigureS26.** Frequency sweeps of networks of differing compositions. Each sample arranged on different worksheets. Column 1: frequency [rad/s]. Column 2: storage modulus [kPa]. **FigureS27.** H NMR at different stages of depolymerization of bottlebrush network. Each sample arranged on different worksheets. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS28.** C NMR at different stages of depolymerization of bottlebrush network. Each sample arranged on different worksheets. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS29.** Si NMR at different stages of depolymerization of bottlebrush network. Each sample arranged on different worksheets. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS30.** SEC traces at different stages of depolymerization of bottlebrush network. Each sample arranged on different worksheets. Column 1: retention time [minutes]. Column 2: normalized refractive index [arbitrary]. **FigureS31.** H NMR of new H-Si macromonomer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS32.** C NMR of new H-Si macromonomer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS33.** Si NMR of new H-Si macromonomer. Column 1: chemical shift [ppm]. Column 2: intensity [arbitrary]. **FigureS30.** SEC traces of new H-Si macromonomers of different molecular weights. Each sample arranged on different worksheets. Column 1: retention time [minutes]. Column 2: normalized refractive index [arbitrary].