Sample Name: Poly(styrene-b-4-vinyl pyridine) Electronic grade Sample #: P5544P-S4VP Structure: CH2 CH b n CH2 1H-NMR Spectrum of Sample 350 300 CH m 250 P5544-S4VP run in CdCl3. 200 N Composition: Mn x 103 PS-b-4VP 1,700.0-b-40.0 150 100 PDI 50 1.20 Tg for PS block: 108 oC 4VP block: Not found Synthesis Procedure: Poly(styrene-b-4-vinyl pyridine) is prepared by living anionic polymerization in THF or THF–DMF solvent mixtures at –78 oC. Polystyrene macroanions were end capped with a unit of diphenyl ethylene (DPE) before adding 4-vinylpyridine (4VP) monomer. For further details please see our published articles.1,2 0 -50 8.0 ppm (f1) 7.0 6.0 5.0 4.0 3.0 2.0 1.0 FTIR spectrum: Characterization: An aliquot of the anionic polystyrene block was terminated before addition of 4-vinyl pyridine and analyzed by size exclusion chromatography (SEC) in DMF to obtain the molecular weight and polydispersity index (PDI). The block copolymer composition was then calculated from 1H-NMR spectroscopy by comparing the peak area of the two aromatic 4VP protons at about 8.5 ppm with the peak area of the aromatic protons of polystyrene at 6.3-7.2 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. Difficulties in determination of chemical compositions of such high molecular weights product: Relationship between weight fraction and area fraction of PS and 4VP 0.2 A1556/A(1556+3059) These high molecular weights polymer by HNMR in CdCl3 do not gives the correct compositions. These polymers were characterized by HNMR in DMF at room temperature and at 50oC. In CdCl3, HNMR chemical shift occurs at 8.4 ppm. The product compositions were verified by titration in acetic acid using crystal violet and HClO4 (per chloric acid) acid-base titration. The Compositions were also verified by FTIR taking the comparison of styrene characteristics at 3059 cm-1 and for 4VP at 1556 Cm-1. From titration it shows the presence of 3 wt % 4VP component and by FTIR 2% Thermal analysis of the samples was carried out using a differential scanning calorimeter (TA Q100) at a heating rate of 10oC/min. The inflection glass transition temperature (Tg) of the sample has been considered. y = 1.5102x - 0.0181 0.1 2 R = 0.9852 Solubility: Poly(styrene-b-4-vinyl pyridine) is soluble in DMF, CHCl3. Purification of the obtained polymer was carried out rigorously as follows to ensure the removal of the catalyst side product: 1. 2. 3. 4. 5. 6. 7. 8. First the polymer soxhlet in Cylcohexane to remove unreacted homiopolystyrene fraction. Dissolved the polymer in CHCl3 and wash with de-ionized distilled water to remove the any soluble organic catalyst side product. Polymer extracted from water with chloroform. Polymer solution in CHCl3 was dried over anhydrous sodium sulfate. Solution filtered and than passed through a column packed with basic Al2O3 . Solution concentrated on rota-evaporator Solution precipitated in cold hexane and redissolved in benzene and freeze dried. Final dried under vacuum for 48h at 50oC. 0 0 0.04 0.08 W4VP/W(4VP+PS) 0.12 0.16 SEC of Sample: P 5 5 5 4 -S 4 V P 0 .1 0 0 .0 8 0 .0 6 0 .0 4 0 .0 2 0 .0 0 -0 .0 2 12 14 16 18 20 22 24 V e (m l) S iz e e x c lu s io n c h ro m a to g ra p h y o f P (s -b -4 V P ) in D M F a t 4 0 o C : P S b lo c k : M n = 1 7 0 0 ,0 0 0 , M w = 2 0 0 0 ,0 0 0 , P I= 1 .1 9 B lo c k C o p o lym e r P S -4 V P (1 7 0 0 ,0 0 0 )-b -4 V P (4 0 ,0 0 0 ), (fro m F T IR ) P I= 1 .2 0 F ro m F T IR 4 V P w t % = 2 .9 4 `Thermograms of sample: sample -0.22 -0.24 H eat Flow (W /g) -0.26 105.42°C -0.28 107.79°C(T) -0.30 -0.32 109.85°C -0.34 -0.36 95 Exo Up 100 105 110 Temperature (°C) 115 120 Universal V4.2E TA Instruments References: (1). S. K. Varshney, X. F. Zhong and A. Eisenberg Macromolecules, 1993, 26, 701-706. (2). Z.Gao, S. K. Varshney, S. Wong, A. Eisenberg Macromolecules, 1994, 27, 7923-7927.