Methanesulfonyl chloride

The chemicals tetraethylorthosilicate (TEOS), n-cetyltrimethylammonium bromide (CTABr), sodium hydroxide, triethanolamine (TEAH₃), (3-isocyanatopropyl) triethoxysilane, iron(III) chloride hexahydrate, iron(II) chloride tetrahydrate, oleic acid, safranin O dye, 2-methoxyethanol, triethylamine, methanesulfonyl chloride, hydrochloric acid, N-phenyldiethanolamine, anhydrous acetonitrile, sodium hydride, 4-aminobenzyl alcohol, sodium nitrite, sodium dithionite and all chemicals for the digestive fluids were provided by Sigma-Aldrich (Madrid, Spain). Magnesium sulfate, sodium carbonate, and all the analytical-grade solvents were purchased from Scharlab (Barcelona, Spain). Aluminum oxide was acquired from Merck (Madrid, Spain). All products were used as received.

Monomethacryloxypropyl-terminated polydimethylsiloxane macromonomers (MCR-M11: M_n ~ 1000 g/mol, $n_{sc}$ 14, and MCR-M17: M_n ~ 5000 g/mol, $n_{sc}$ 70) were obtained from Gelest and purified using basic alumina columns to remove inhibitor. Aminopropyl terminated polydimethylsiloxane (DMS-A15, M_n~3,000 g/mol), trimethylsiloxy terminated polydimethylsiloxane (DMS-T72, M_n ~ 500,000 g/mol), and chlorine terminated polydimethylsiloxane (DMS-K05, M_n ~ 425–650 g/mol) were purchased from Gelest and used as received. PEGMA macromonomer (M_n ~ 500 g/mol) was obtained from Sigma-Aldrich and purified using basic alumina columns to remove inhibitor. Ethylene bis(2-bromoisobutyrate) (2f-BiB), tris[2-(dimethylamino)ethyl]amine (Me6TREN), Copper(I) chloride (CuCl), Copper(I) bromide (CuBr), triethylamine (TEA), methanesulfonyl chloride, tris(hydroxypropyl)phosphine (THPP), Sodium azide, isophorone diisocyanate (IPDI), and Tin(II) 2-ethylhexanoate, furfuryl isocyanate, maleic anhydride, furan, ethanolamine, isocyanatoethyl methacrylate were purchased from Sigma-Aldrich and used as received. Toluene, anisole, isopropanol, dichloromethane (DCM), N,N-dimethylformamide (DMF), and tetrahydrofuran (THF) were purchased from VWR Chemicals and used as received.

α,ω-Dihydroxy PEG (M_n ~ 1.5 and 10 kDa), α-methoxy-ω-hydroxy PEG (M_n ~ 5 kDa), α,ω-dihydroxy Pluronic^® F-127 (M_n ~ 12.6 kDa), α-butoxy-ω-hydroxy PPG (M_n ~ 340 Da), methanesulfonyl chloride (MsCl; ≥99.7%), zinc (Zn; granular, 20-30 mesh, ACS reagent, ≥99.8%), triethylamine (TEA; ≥99.5%), ammonium chloride (NH₄Cl; ≥99.5%) and deuterated chloroform (CDCl₃, 99.8 atom % D) were purchased from Sigma–Aldrich. Hydroxy-terminated 4-armed PEG (M_n ~ 10 kDa) was purchased from creative PEG works. α,ω-Dihydroxy PEG (M_n ~ 35 kDa) was purchased from Fluka. α,ω-Dihydroxy PEG (M_n ~ 4 kDa) was purchased from Ajax. Sodium Azide (NaN₃; ≥99%), dichloromethane (DCM), tetrahydrofuran (THF) and N,N-dimethylformamide (DMF) were all of analytical grade and were purchased from ChemSupply (Gillman, Australia). Methanol (MeOH) of HPLC grade was purchased from ChemSupply (Gillman, Australia). All reagents were used as received. Ultrapure water with a resistivity of >18.2 MΩ.cm was obtained from a Sartorius Arium Pro ultrapure water system (Göttingen, Germany). Ultrahigh purity argon (99.999%) was purchased from BOC (BOC Gas, Australia).