Sample Name: Poly(styrene-b-2-vinyl pyridine-b-ethylene oxide) Sample #: P4866-S2VPEO 1H-NMR Spectrum of the polymer Structure: CH2 1000 CH b n CH2 CH CH2CH2O CH2 CH2 O H m N 500 P4866-S2VPEO Composition: Mn x 103 S-b-2VP-b-EO 3.2-b-1.3-b-3.0 PDI Synthesis Procedure: Poly(styrene-b-2-vinyl pyridine-ethylene oxide) triblock copolymer is prepared by living anionic polymerization. The triblock is synthesized in 2 steps: 1st a OH terminated Poly(S-b-2VP) is synthesized in THF at –78oC using LiCl as an additive. Polystyrene macroanions were end capped with a unit of diphenyl ethylene (DPE) before adding 2vinylpyridine (2VP) monomer. The reaction was terminated with ethylene oxide. The OH terminated Poly(S-b-2VP) was converted to potassium salt by addition of K-naphthalene and freshly distilled ethylene oxide. The scheme of the reaction is depicted below: m CH2 n CH2 10.83 0 10.0 5.0 0.0 ppm (f1) SEC of the triblock polymer: P 4 8 6 6 -S 2 V P E O 0 .1 5 0 .1 0 CH 1. CH 9.44 1.00 1.10 N Sec BuLi/THF at -78oC CH 2 CH CH2 Li CH CH 2 b n n CH CH 2CH 2OH m O 0 .0 5 N 2. 1. K naphthalene 2. EO 0 .0 0 CH2 CH b n CH2 CH CH2CH2O CH2 CH2 O H m 12 14 16 18 20 22 24 26 28 Ve N S iz e E x c lu s io n C h r o m a to g r a p h y : F ir s t P S b lo c k , M n = 3 2 0 0 , M w /M n = 1 .1 5 Characterization: An aliquot of the anionic polystyrene block was terminated before addition of 2VP and analyzed by size exclusion chromatography (SEC) to obtain the molecular weight and polydispersity index (PDI). The Block copolymer composition was then calculated from 1HNMR spectroscopy by comparing the peak area of the 2VP proton at 8.2 ppm with the peak area of the aromatic protons of polystyrene at 6.3-7.2 ppm and EO protons at 3.6 ppm. The composition of the block copolymer can also be determined by titration in acetic acid/HClO4 using crystal violet indicator. Copolymer PDI is determined by SEC. Solubility: Poly(styrene-b-2 vinylpyridine-b-ethylene oxide) is soluble in THF, toluene, and CHCl3 . The triblock copolymer can also be solubilized in methanol, ethanol depending on its composition. The polymer readily precipitates from hexanes, ether and water. P S 2 V p , th e d ib lo c k P S ( 3 2 0 0 )- b - P 2 V p ( 1 3 0 0 ) , M w /M n = 1 .2 8 P S 2 V P E O , th e tr ib lo c k P S ( 3 2 0 0 ) - b - P 2 V p ( 1 3 0 0 ) - b - P E O ( 3 0 0 0 ) M w /M n = 1 .1 0 ( c o m p o s itio n fr o m H N M R ) References: 1. S. K. Varshney, X. F. Zhong and A. Eisenberg Macromolecules 1993, 26, 701-706. 2. Gohy J.-F., Willet N., , Zhang J.-X., Varshney S., Jerome, ., pH dependence of the morphology of aqueous micelles formed by poly(styrene)-blockpoly(2-vinylpyridine)-block-poly(ethylene oxide) copolymers, e-polymers 2002, 35. 3. Gohy, J.-F., Lohmeijer, B Varshney S,K, Decamps B., Leroy E., Boileau S., Schubert U. S., Stimuli-responsive aqueous micelles from an ABC metallo-supramolecular triblock copolymer, Macromolecules 2002, 35, 97489755. 4. Gohy, J.-F., Mores S., Varshney S. K., Jerome, R., Self-organization of water-soluble complexes of a poly(2-vinylpyridinium)-block-poly(ethylene oxide) diblock and a fluorinated anionic surfactant, Macromolecules 2003, 36, 25792581. 5. Leil L., Gohy J.-F., Willet N., , Zhang J.-X., Varshney S., Jerome R., Tuning of the morphology of core-shell-corona aqueous micelles: I. sphere–to-cylinder transition, Macromolecules 2004, 37, 1089-1094. 6. Jean-Francois Gohy, Bas G. G. Lohmeijer, Sunil K. Varshney, and Ulrich S. Schubert, Covalent vs Metallo-supramolecular Block Copolymer Micelles” Macromolecules 2002, 35, 7427-7435. Thermal analysis results at a glance Thermal Analysis of the sample P4866-S2VPEO Thermal analysis of the samples was carried out on a TA Q100 differential scanning calorimeter at a heating rate of 10oC/min.The midpoint of the slope change of the heat flow plot of the second heating scan was considered as the glass transition temperature (Tg). Tg: -37oC Thermogram for PS block: Melting curve for PEO block For PS block: Tg: 87oC -0.204 For 2VP block: Tg: Not distinct For PEO block Tm: Not found Tc: Not found -0.18 -0.20 78.74°C -0.206 -33.45°C -0.208 H eat Flow (W /g) H eat Flow (W /g) -0.22 86.92°C(T) 89.24°C -0.24 -26.78°C(T) -0.26 -0.28 -0.210 -21.89°C -0.30 -0.32 -45 -0.212 75 Exo Up 80 85 90 Temperature (°C) 95 100 Exo Up Universal V4.2E TA Instruments . -40 -35 -30 Temperature (°C) -25 -20 -15 Universal V4.2E TA Instruments