Sec butyllithium

All chemicals were used as received unless otherwise noted. n-Butyllithium (n-BuLi, 2 M in cyclohexane), sec-butyllithium (sec-BuLi, 1.4 M in cyclohexane), tetrahydrofuran (THF, anhydrous, ≥99.9%, inhibitor-free), styrene, platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex solution (in xylene, Pt ≈ 2%), 1,1-diphenylethylene (DPE, 97%), lithium bromide (LiBr, ≥99%), and chlorotrimethylsilane (purified by redistillation, ≥99%) were purchased from Sigma-Aldrich. Hexamethylcyclotrisiloxane (D₃, 95%), 1,3,5-trivinyl-1,3,5-trimethylcyclotrisiloxane (D₃V), chlorodimethylsilane (CDMS, 98%), and ((chloromethyl)phenylethyl)dimethylchlorosilane (CMPDMS) were purchased from Gelest. Anhydrous toluene was obtained from Acros Organics and other solvents such as cyclohexane, methanol, and acetone were purchased from Biosolve.

Benzene (VWR, Pris, France, 99%) and tetrahydrofuran (THF, VWR, Gliwice, Poland, ≥99.0%) were dried over calcium hydride (CaH₂, 95%) followed by distillation into a glass cylinder containing polystyrilithium (PS⁽⁻⁾Li⁽⁺⁾) for benzene, and sodium/potassium alloy for THF, under high vacuum. Styrene (Sigma-Aldrich, 99%) was dried over CaH₂ followed by distillation over di-n-butylmagnesium (Bu₂Mg) and stored at −20 °C in pre-calibrated ampoules. 2-Vinylpyridine (2VP,) was dried twice over CaH₂ and subsequently purified using a sodium mirror and triethylaluminum (TEA), followed by distillation into pre-calibrated ampoules. sec-Butyllithium (1.4 M in cyclohexane, Sigma-Aldrich) was diluted to the appropriate concentration in benzene for the polymerization of Styrene, or in n-hexane (Sigma-Aldrich, 95%) for the polymerization of 2VP, and stored under vacuum at −20 °C within a home-made glass apparatus equipped with ampoules. Ethylene oxide (EO, Sigma-Aldrich, 99.5%) was purified by distillation over CaH₂, over n-BuLi at 0 °C, and stored under high vacuum in ampoules. Methanol (MeOH, Sigma-Aldrich, ≥99.9%) was purified by distillation over CaH₂ and stored in ampoules under a high vacuum.

Monomers (Sigma-Aldrich) were purified with either n-butyllithium (Sigma-Aldrich) (isoprene, 1,3-butadiene, and ethylene oxide) or di-n-butylmagnesium (Sigma-Aldrich) (styrene). Organic solvents were used directly from a solvent drying system (JC Meyer Solvent Systems). The Monomers isoprene, 1,3-butadiene, and styrene were initiated using sec-butyllithium (Sigma-Aldrich). Potassium naphthalenide solutions used for the poly(ethylene oxide) polymerizations were prepared 24 h before the initiation of the polymerization. The nuclear magnetic resonance (NMR) experiments were performed on an Avance AV3HD 500 NMR spectrometer (Bruker) at room temperature. All the obtained spectra were calibrated according to the residual solvent peak. The size-exclusion chromatography (SEC) experiments were performed on an EcoSEC HLC-8320GPC (Tosoh Bioscience) equipped with a DAWN multi-angle static light scattering (SLS) detector (Wyatt Technology).
Mono-hydroxyl functionalized PEO, diblock copolymers SO, BO and IO were synthesized via standard anionic polymerization^{69 (link)}. Triblock copolymers SOS, BOB and IOI were synthesized by terminating the corresponding diblock copolymers with the coupling agent α,αʹ-dibromo-p-xylene^{70 (link)}. All the polymers were characterized with SEC and ¹H NMR (see detailed data in supporting information).