DOI: 10.5061/dryad.cjsxksncm
title: Heterotelechelic silicones: Facile synthesis and functionalization using silane-based initiators

description: The synthetic utility of heterotelechelic polydimethylsiloxane (PDMS)
 derivatives is limited due to challenges in preparing materials with high
 chain-end fidelity. In this study, anionic ring-opening polymerization
 (AROP) of hexamethylcyclotrisiloxane (D3) monomer using a specifically
 designed silyl hydride (Si–H)-based initiator provides a versatile
 approach towards a library of heterotelechelic PDMS polymers. A novel
 initiator, where the Si–H terminal group is connected to a C atom (H–Si–C)
 and not an O atom (H–Si–O) as in traditional systems, suppresses
 intermolecular transfer of the Si–H group, leading to heterotelechelic
 PDMS derivatives with a high degree of control over chain-ends. In-situ
 termination of the D3 propagating chain end with commercially available
 chlorosilanes (alkyl chlorides, methacrylates, and norbornenes) yields an
 array of chain-end functionalized PDMS derivatives. This diversity can be
 further increased by hydrosilylation with functionalized alkenes
 (alcohols, esters, and epoxides) to generate a library of heterotelechelic
 PDMS polymers. Due to the living nature of ring opening polymerization and
 efficient initiation, narrow-dispersity (Đ &lt; 1.2) polymers spanning
 a wide range of molar masses (2 – 11 kg mol−1) were synthesized. With
 facile access to α-Si–H and ω-norbornene functionalized PDMS macromonomers
 (H–PDMS–Nb), the synthesis of well-defined super-soft (Gʹ = 30 kPa) PDMS
 bottlebrush networks, which are difficult to prepare using established
 strategies, was demonstrated.
description: Nuclear magnetic resonance
 spectroscopy <sup>1</sup>H-, <sup>13</sup>C- and
 <sup>29</sup>Si-NMR spectra were collected on a Bruker Avance
 NEO 500 MHz using chloroform as a deuterated solvent. IR spectra was
 measured with a Thermo Nicolet iS10 FTIR spectrometer equipped with a
 Smart Diamond attenuated total reflectance (ATR)
 accessory. Size
 exclusion chromatography Size exclusion chromatography (SEC) was measured using
 Waters e2695 separation module with a Waters 2414 differential refractive
 index detector equipped with two columns (PLgel, 5 μm MiniMIX-D, 250×4.6
 mm columns + guard) with chloroform containing 0.25% TEA at 35 °C as the mobile
 phase.
 Matrix assisted laser desorption ionization-time of flight
 mass spectrometry MALDI-TOF MS spectrometry was measured using a Bruker
 Microflex LRF MALDI TOF mass spectrometer in positive reflection mode; the
 analyte, matrix (DCTB) were dissolved in chloroform at the concentration
 of 2.5 and 10 mg/mL respectively, and cationization agent (NaTFA) was
 dissolved in chloroform at concentrations of 1 mg/mL, then mixed in a
 volume ratio of 20 : 1 : 1 (DCTB : NaTFA : 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. Mechanical analysis
 Frequency sweeps and isochronal temperature sweeps were
 obtained on a TA Instruments ARES G2 in oscillatory shear mode with an 8
 mm parallel-plate geometry and a nitrogen-purged forced–convection
 oven.
description: # Heterotelechelic silicones: Facile synthesis and functionalization using
 silane-based initiators 
 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. Compounds are denoted as such:
 hexamethylcyclotrisiloxane (D3), Polydimethylsiloxane (PDMS), Methacrylate
 (MA), Norborene (Nb), Chloropropyl (Cl), Hydride (H), Polystyrene (PS).
 Figures that are pictures and illustrations will not be included in the
 folders. This includes Figure 1, Scheme 1, Figure 5, and Figure 8.   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. 2a: <sup>1</sup>H-NMR of H–PDMS–MA 2b:
 <sup>29</sup>Si-NMR of H–PDMS–MA 3a: MALDI-tof 3b: MALDI-tof
 4a: conversion plot of H–PDMS–MA 4b: SEC of H–PDMS–MA 6: SEC of
 ATRP-PDMS-Cl and PS-PDMS-Cl 7: SEC of PDMS bottlebrush S1:
 <sup>1</sup>H-NMR S2: <sup>13</sup>C-NMR S3:
 <sup>29</sup>Si-NMR S4: <sup>1</sup>H-NMR S5:
 <sup>13</sup>C-NMR S6: <sup>29</sup>Si-NMR S7:
 FT-IR S8: SEC S9: MALDI-tof S10: <sup>1</sup>H-NMR S11:
 <sup>13</sup>C-NMR S12: <sup>29</sup>Si-NMR S13:
 FT-IR S14: SEC S15: MALDI-tof S16a: MALDI-tof S16b: MALDI-tof S17:
 <sup>1</sup>H-NMR S18: <sup>13</sup>C-NMR S19:
 <sup>29</sup>Si-NMR S20: FT-IR S21: SEC S22: MALDI-tof S23:
 <sup>1</sup>H-NMR S24: <sup>13</sup>C-NMR S25:
 <sup>29</sup>Si-NMR S26: FT-IR S27: SEC S28: MALDI-tof S29:
 <sup>1</sup>H-NMR S30: <sup>13</sup>C-NMR S31:
 <sup>29</sup>Si-NMR S32: FT-IR S33: SEC S34: MALDI-tof S35:
 <sup>1</sup>H-NMR S36: <sup>13</sup>C-NMR S37:
 <sup>29</sup>Si-NMR S38: FT-IR S39: SEC S40: MALDI-tof S41:
 <sup>1</sup>H-NMR S42: <sup>13</sup>C-NMR S43:
 <sup>29</sup>Si-NMR S44: FT-IR S45: SEC S46: MALDI-tof S47:
 <sup>1</sup>H-NMR S48: <sup>13</sup>C-NMR S49:
 <sup>29</sup>Si-NMR S50: FT-IR S51: SEC S52: MALDI-tof S53:
 <sup>1</sup>H-NMR S54: <sup>13</sup>C-NMR S55:
 <sup>29</sup>Si-NMR S56: FT-IR S57: SEC S58: MALDI-tof S59:
 <sup>1</sup>H-NMR S60: <sup>13</sup>C-NMR S61:
 <sup>29</sup>Si-NMR S62: SEC S63:
 <sup>1</sup>H-NMR S64: <sup>13</sup>C-NMR S65:
 <sup>29</sup>Si-NMR S66: FT-IR S67: SEC S68:
 <sup>1</sup>H-NMR S69: <sup>13</sup>C-NMR S70:
 <sup>29</sup>Si-NMR S71: FT-IR S72: SEC S73: MALDI-tof S74:
 <sup>1</sup>H-NMR S75: <sup>13</sup>C-NMR S76:
 <sup>29</sup>Si-NMR S77: FT-IR S78: SEC S79: Curing profile
 S80: Frequency sweep