Chemical Modification of Polysulfone by Anionic Methods

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CHAPTER 3 EXPERIMENTAL

Materials and Glassware

All chemicals and solvents were purchased from the Sigma Aldrich Chemical Company, unless otherwise stated. Styrene and methyl methacrylate were purified by drying over calcium hydride followed by vacuum distillation and drying over molecular sieves prior to use. Tetrahydrofuran (THF) was freshly distilled from Na/benzophenone after stirring at room temperature for few days39,49. Distillation of THF was performed when the solution had a purple-blue colour which is an indication of the dryness of the solvent and the absence of reactive impurities. Excess sodium metal was used to ensure the complete conversion of benzophenone to the benzophenone radical anion since traces of unreacted benzophenone would sublime upon subsequent distillation of THF.
Copper (I) bromide, (1-bromoethyl)benzene, 4-aminobenzophenone, diphenyl ether, 2,2′-bipyridyl (99+%), 4,4′-diaminobenzophenone, n-butyllithium (1.6M in hexane), methyllithium (1.6M in diethyl ether), methyl triphenylphosphonium bromide, potassium tert-butoxide, calcium hydride and di-2-pyridylketone were used as received. 4,4′-Bis(dimethylamino)benzophenone was recrystallized twice from absolute ethanol before use.
All glassware was oven dried at 120 oC for 24 hours prior to use and all reactions were carried out under a dry argon or nitrogen atmosphere, where applicable.

Characterization

Nuclear Magnetic Resonance Spectrometry (NMR)
1H NMR spectra were recorded on a Varian Gemini 300 MHz spectrometer with CDCl3 solvent at ambient temperature. Polymers were dissolved in an appropriate deuterated solvent to give a viscous polymer solution in an NMR tube.
Fourier Transform Infrared Spectroscopy (FTIR)
Infrared spectra were recorded on a Perkin Elmer 883 Infrared spectrophotometer or on a Digilab FTS-700 FTIR Spectrometer equipped with a UMA 600 ATR Microscope attachment and a germanium Crystal ATR at wave numbers from 4000 to 600 cm-1. Polymer samples were placed over the ATR crystal and maximum pressure applied using the slip-clutch mechanism.
Size Exclusion Chromatography (SEC)
Molecular weights and molecular weight distributions of polymers were measured by size exclusion chromatography (SEC) on a Waters Alliance SEC autosampler equipped with a Phenogel guard column and a Phenogel column (5 µ, 500Å pore size, 1K-15K MW range, 300 mm x 7.8 mm) in series with refractive index and dual angle laser light scattering detectors. THF was used as an eluent at a flow rate of 1 mL/min at 30 oC. The lazer light scattering detector of the SEC system was calibrated with monodisperse polystyrene and poly(methyl methacrylate) standards (Aldrich Chemical Company). Polymers were dissolved in THF (4 mg/1.5 mL) before characterization by size exclusion chromatography.
Gas Chromatography (GC)
The monomer conversion was determined by gas chromatography using a Shimadzu Gas Chromatograph 17Å equipped with PB-5 M column (30 m x 0.32 mm; 0.25 µm film) at a constant flow rate of 1.7 mL/min. The initial column temperature was set at 90 oC with a hold time of 3 minutes, followed by an increase in temperature to 280 oC at a heating rate of 10 oC /min. Tetrahydrofuran (THF) was used as the internal standard for the analysis. An aliquot of 1 µL of the test sample was injected via a syringe into the injection port for the GC analysis.
Thermogravimetric Analysis (TGA)
Thermogravimetrical curves were generated on a TA instrument Auto Hi-Res Q500 Thermogravimetrical Analyzer at a heating rate of 10 oC /min under nitrogen atmosphere. Approximately 600 mg of the polymer sample was placed on a preweighed TGA pan for analysis.
Differential Scanning Calorimetry (DSC)
Glass transition temperatures of polymeric samples were determined on a TA Instruments Auto MDSC Q100 Differential Scanning Calorimeter by heating the polymers from 10 oC to 700 oC. Polymer sample sizes with masses ranging from 5-10 mg were measured into a DSC sample pan for analysis.
Thin Layer Chromatography (TLC)
Thin layer chromatographic analyses of all the products were performed on Silica gel plates (Merck, Silica Gel 60 F254). Samples were dissolved in suitable solvents. Solutions containing the sample were then spotted on the TLC plates, about one centimeter from the base and developed in a standard chromatography chamber.
Melting point determination
The melting points of the different samples are uncorrected. The melting points of samples were recorded on a Stuart Melting Point Analyser (Barloworld Scientific Limited) with a measuring range of 25 – 400 oC, accuracy of ± 0.3 oC (25 – 200 oC) and ± 0.5 oC (200 – 400 oC) and reproducibility of ± 0.2 oC. The dried samples were loaded into capillary tubes, with sample height between 2.0 mm and 3.0 mm and placed in the melting point apparatus.
Non-Aqueous Titrations
The number average molecular weights of the primary and tertiary amine functionalized polymers were determined by non-aqueous titrations of amine groups186-191. The concentrations of primary and tertiary amine end groups in the functionalized polymers were determined by separate non-aqueous titrations of 0.1 g polymer samples in a 1/1 (v/v) mixture of chloroform and glacial acetic acid with standardized perchloric acid (0.01 M) in glacial acetic acid using methyl violet as an indicator.
Contact Angle Tests
Contact angle data was obtained at the University of Stellenbosch with an ERMA G-1 contact angle meter at 20 oC using pure water as probe liquid.
Water Permeability Tests
Water permeability tests were carried out at 25 oC at transmembrane pressures ranging between 20 and 100 kPa and membrane surface of 0.0050731 m2 using pure water obtained by ion exchange and reverse osmosis treatment.
Flux Data
Flux data were obtained by passing pure water under pressure through the flat sheet membranes and collecting permeate on a Mettler balance to determine the water permeability of the membranes.
Atomic Force Microscopy (AFM)
Atomic force microscopy (AFM) images of unmodified and dipyridyl functionalized polysulfone membranes were obtained at the University of Stellenbosch with an Explorer TMX 2000 AFM from Topometrix operated in the low amplitude non-contact mode. The resonance frequency of the low frequency non-contact silicon cantilevers (Nanosensors GmbH) was 35-65 N/m. The low resonance cantilever was 220 µm long and 40 µm wide. The average roughness of the membrane surface, Ra was determined using the following equation:
where N is the total number of points in the image matrix and Zi is the height of the ith point of reference value. AFM analyses were performed at different scan ranges for each polysulfone sample at different places on the sample. At least three interpore regions of each membrane were analyzed to obtain average Ra values.
Scanning Electron Microscopy (SEM)
Scanning electron microscopy (SEM) photographs were obtained at the University of Pretoria with a JEOL 6000F in-lens field emission SEM and a JEOL 840 scanning electron microscope as follows:
(a) Freeze drying
To prevent the collapse of the polysulfone membrane pores, the membranes were kept in distilled water. The wet membranes were cut into 0.4 cm2 (0.4 cm x 1 cm) samples and freeze-dried in liquid propane at -180 oC with a Riechert KF 80 freeze plunger. The frozen samples were transferred under liquid nitrogen into slots in a copper block (63 mm x 63 mm x 15 mm). The copper block was kept completely immersed in liquid nitrogen in a plastic container, thus keeping the material under nitrogen atmosphere and preventing the condensation of moisture onto the sample. The copper block was thereafter transferred to a Fisons high vacuum unit where the evacuation started immediately. The temperature of the copper block was below -130 oC when the vacuum reached 1.33 Pa (1 x 10 -2 Torr). Freeze-drying was carried out over 2 days, during which the temperature steadily increased back to room temperature.
(b) Sample preparation
Samples of the membrane were cut and placed flat and upright onto the polished side of graphite stubs to view the surface and cross-section, respectively of the membrane. The stubs were made from spectrographic rods turned down to a diameter of 5 mm with a lathe. Disks of 1 mm thickness were cut from the rod and subsequently polished. Double-sided carbon tape was used to secure the samples onto the stub. Furthermore, carbon dag (Leit C, Neubauer Chemikalien) was applied to the edges of the sample for additional support and to reduce the charging of the specimen surface.
(c) Coating and sample viewing
Samples were coated with chromium (ca. 3-4 nm) in a Gatan Ion beam coater, model 681. The samples were viewed at a minimum magnification of 5000x. To obtain lower magnification photos the samples were gold spurred in a Polaron E5200 sputter coater for viewing.

Anionic Synthesis of Functionalized Polysulfone

Purification of Polysulfone, (1)

Commercially available polysulfone, (1) (Ultrason S, BASF, Mn = 47 x 103 g/mol, Mw/Mn = 1.05) was dissolved in THF and precipitated in methanol, filtered and vacuum dried at 120 oC prior to the chemical modification reactions.

The synthesis of 2,2′-vinylidenedipyridine, (2)

The synthesis of 2,2′-vinylidenedipyridine, (2) according to the procedures outlined by Eckard and Summers192 and Summers and coworkers193 afforded the desired product in low yields. Thus, a new method to synthesize 2,2′-vinylidenedipyridine, (2) was developed using the synthetic route outlined by Subramanyam194, with modifications.
Under an argon atmosphere, potassium tert-butoxide (27.51 mL of a 1.0 M solution, 0.027 mol) was added to methyltriphenylphosphonium bromide (9.7 g, 0.027 mol) in freshly distilled anhydrous THF (200 mL) at 0 oC and the reaction stirred for 1.5 hours. After complete reaction, di-2-pyridylketone (5.0 g, 0.027 mol) in dry THF (100 mL) was added to the freshly prepared phosphorous ylide at 0 oC. The resultant dark orange solution was stirred for 12 hours at room temperature to achieve complete reaction. The colour of the reaction mixture changed from dark-orange to orange-green to brown. The reaction was quenched by the addition of methanol (2 mL). The triphenylphosphine oxide salt which precipitated from the solution was removed by vacuum filtration. The filtrate was concentrated on a rotary evaporator and the resultant brown oil purified by silica gel chromatography using toluene as eluent to give 4.21g (92%) of pure 2,2′-vinylidenedipyridine as a light brown oil: 1H NMR (CDCl3): δ 6.05 ppm [s, 2H, CH2], 6.97-7.70 ppm [m, 6H, aromatic H], 8.50-8.60 ppm [d, 2H, aromatic H]; FTIR (oil): 1634 cm-1 (C=N); TLC (Silica Gel 60F254, Merck),
Rf (acetonitrile) = 0.35.

Synthesis of Dipyridyl Functionalized Polysulfone, (3)

The synthesis of dipyridyl functionalized polysulfone with 45% degree of functionalization (PFPS-45) was conducted according to the procedure of Summers and coworkers39,193. To improve the degree of functionalization, the preparation of dipyridyl functionalized polysulfone with 80% (PFPS-80) and 95% (PFPS-95) degree of functionalization were effected using 10% and 20% molar excess of 2,2′-vinylidenedipyridine, (2) respectively. In a typical procedure, for the preparation of dipyridyl functionalized polysulfone, PFPS-80, dry, unmodified polysulfone, (1) (1.0 g, 0.0023 mol, Mn = 47 x 103 g/mol; Mw/Mn = 1.05) was transferred into a clean, dry 250 mL round bottomed flask under an argon atmosphere. Freshly distilled, dry THF (40 mL) was added to dissolve the polymer. The reaction mixture was cooled to -78 oC using a dry ice/isopropanol bath. n-Butyllithium (2.2 mL of a 1.6 M solution in hexane, 0.0035 mol) was added to the reaction mixture. The reaction mixture was stirred for 2 hours at -78 oC to effect complete metalation. Freshly prepared 2,2′-vinylidenedipyridine, (2)
(1.03 g, 0.0057 mol) in THF (20 mL) was then added to the viscous deep-red lithiated polymer via a cannula, whereupon the reaction mixture turned to a deep orange colour. The reaction mixture was allowed to stir at -78 oC for 4 hours. The colour and the viscosity of the reaction mixture remained unchanged. Upon quenching the reaction mixture with methanol (2 mL), a homogenous orange solution was obtained. The mixture was concentrated on a rotary evaporator and the functionalized polysulfone was precipitated in excess methanol, filtered off and dried at 120 oC to afford 1.35 g (96% yield) of dipyridyl functionalized polysulfone, (3), PFPS-80, as a white solid: 1H NMR (CDCl3): δ 3.78-3.91 ppm [broad m, 2H, CH2], 4.68-4.85 ppm [broad m, 1H, H,CH], 6.43-8.62 ppm [m, aromatic H]; FTIR (film): 1634 cm-1 (C=N); SEC: Mn = 56.87 x 103 g/mol, Mw/Mn = 1.22.
The preparation of dipyridyl functionalized polysulfone, (3), PFPS-95 was conducted via a similar procedure by adding 20% molar excess of 2,2′-vinylidenedipyridine, (2) to the corresponding lithiated polysulfone derivative.

Membrane Preparation

Membranes were prepared from 15% (w/w) polymer (PS, PFPS-45, PFPS-80 and PS-1-80) solutions in N-methyl-2-pyrrolidone. Sample PS-1-80 is a blend of 1% PFPS-80 in PS. Solutions were cast at 25 oC on a glass plate to form thin films with thickness of 150 µm. After exposure to air for 15 seconds at 20 oC and 60% relative humidity, the thin films were immersed in water at 15 oC. After an immersion period of 5 minutes in distilled water, the membranes detached from plate and were leached for an additional 3 hours under running water before use.

Atom Transfer Radical Polymerization: Synthesis of Amine Chain End Functionalized Polymers

 Primary Amine Functionalized Initiator Precursor: Synthesis of 1-(4-Aminophenyl)-1-phenylethylene, (4)

Freshly distilled tetrahydrofuran (100 mL) was added to a three necked round bottom flask containing methyltriphenylphosphonium bromide (10.81 g; 0.0303 mol). The mixture was purged with argon for 15 minutes. Methyllithium (18.91 mL of a 1.6 M solution in diethyl ether, 0.0303 mol) was added dropwise to the reaction flask via a syringe at 0 oC to form a ylide. The mixture turned yellow upon addition of methyllithium. After stirring for 4 hours at room temperature, the resultant phosphorous ylide was transferred via a cannula into the solution of 4-aminobenzophenone (5.0 g, 0.0254 mol) and dry THF (100 mL) at 0 oC with stirring. The reaction mixture immediately turned orange in colour. After stirring the reaction mixture at room temperature for 12 hours, methanol (2 mL) was added to quench the reaction. The triphenylphosphine oxide salt, which precipitated from solution, was removed by vacuum filtration. The filtrate was concentrated and the crude product was purified by column chromatography using toluene as eluent. After removing the solvent via a rotary evaporator, yellow-white crystals were formed. Recrystallization of the product from 80% aqueous ethanol gave 4.47 g (90%) of 1-(4-aminophenyl)-1-phenylethylene, (4) as light yellow crystals: mp = 81.2-82.6 oC (lit. mp51 = 80-81 oC); 1H NMR (CDCl3):
δ = 3.67 ppm [broad s, 2H, NH2], 5.19 ppm [s, 2H, CH2], 6.62 and 7.18 ppm [m, 6H and 5H respectively, aromatic H]; FTIR (solid): 3468 cm-1 (N-H); TLC: Rf (toluene) = 0.44.

Synthesis of • -Aminophenyl Functionalized Polystyrene, (6)

All polymerization reactions were performed in Schlenk flasks and under dry argon atmosphere.
In a typical procedure, copper (I) bromide (0.0735 g, 0.5122 x 10-3 mol) and 2,2′-bipyridyl (0.2401 g, 1.5366 x 10-3 mol) were added to a Schlenk flask, followed by the successive addition of (1-bromoethyl)benzene (0.095 g, 0.07 mL, 0.5122 x 10-3 mol), 1-(4-aminophenyl)-1-phenylethylene, (4) (0.1 g, 0.5122 x 10-3 mol) and diphenyl ether (1.7 mL). The reaction mixture was stirred at room temperature for 5 minutes. The heterogenous mixture was degassed by three freeze-pump-thaw
cycles. Under an argon atmosphere, the reaction mixture was heated to 110 oC for 60 minutes with stirring. The disappearance of 1-(4-aminophenyl)-1- phenylethylene, (4) was monitored by TLC analysis. Freshly distilled styrene (1.86 mL, 1.6903 g, 0.0162 mol) was added to the resultant green reaction mixture via a stainless steel syringe at room temperature and the reaction mixture was heated at 110 oC for 12 hours. Upon cooling and addition of tetrahydrofuran (10 mL), the resultant green solution was purified by passage through a short silica gel column to remove copper and ligand impurities. The polymer solution was concentrated on a rotary evaporator and precipitated from THF solution into excess methanol to afford 1.94 g of the corresponding • – aminophenyl functionalized polystyrene, (6) as a white solid: 1H NMR: δ = 1.20 – 2.39 ppm [m, polystyrene CH2 and CH], 3.69 ppm [broad s, 2H, NH2], 6.26 – 7.41 ppm [aromatic H]; FTIR (solid): 3469 cm-1 (N-H); Mn, theory = 3.30 x 103 g/mol; SEC: Mn = 3.10 x 103 g/mol, Mw/Mn = 1.08; Mn, titration = 3.35 x 103 g/mol.

Primary Diamine Functionalized Initiator Precursor: Synthesis of 1,1-Bis(4-aminophenyl)ethylene, (7)

Under an argon atmosphere, freshly distilled tetrahydrofuran (100 mL) was added to a dry three necked round bottom flask containing methyltriphenyl-phosphonium bromide (10.05 g; 0.0281 mol). The mixture was degassed with argon for 15 minutes. Methyllithium (17.60 mL of a 1.6 M solution in diethyl ether, 0.0281 mol) was added dropwise to the reaction flask via a syringe at 0 oC. The mixture turned yellow upon addition of methyllithium. After stirring for 4 hours at room temperature, the resulting ylide was transferred via a cannula into a solution of 4,4′-diaminobenzophenone (5.0 g; 0.0236 mol) in dry THF (100 mL) at 0 oC, with stirring. The reaction mixture was heated to reflux for 12 hours. Methanol (2 mL) was then added to quench the reaction. The triphenylphosphine oxide salt, which precipitated from solution, was removed by vacuum filtration. The filtrate was concentrated and the crude product was purified by column chromatography using hexane/ethyl acetate (v/v, 20/80) to give a dark brown solid. Recrystallization of the solid from 80% aqueous ethanol solution gave 3.98 g (80%) of pure 1,1-bis(4-aminophenyl)ethylene, (7) as pale yellow crystals: mp = 160.5 – 162.0 oC (lit. mp194,195 = 159-160 oC); 1H NMR (CDCl3): δ = 3.69 ppm [broad s, 4H, 2 x NH2], 5.21 ppm [s, 2H, =CH2], 6.63 and 7.20 ppm [d x d, 8H, aromatic H]; FTIR (solid): 3443 cm-1 (N-H); TLC: Rf (hexane/ethyl acetate, v/v, 20/80) = 0.71.

Synthesis of • -Bis(aminophenyl) Functionalized Polystyrene, (9)

In a typical experiment, under argon atmosphere, copper (I) bromide (0.0493 g, 0.3433 x 10-3 mol), 2,2′-bipyridyl (0.1609 g, 1.030 x 10-3 mol), (1-bromoethyl)benzene (0.0640 g, 0.047 mL, 0.3433 x 10-3 mol), 1,1-bis(4-aminophenyl)ethylene, (7) (0.072 g, 0.3433 x 10-3 mol) and diphenyl ether (1.70 mL) were added to the Schlenk tube. The tube was tightly sealed with a rubber septum and degassed by three freeze-pump-thaw cycles. The Schlenk tube was then immersed in an oil bath, preset at 110 oC, for an hour. The disappearance of 1,1-bis(4-aminophenyl)ethylene, (7) was monitored by TLC. Subsequently, freshly distilled styrene (1.70 mL, 1.545 g, 0.0135 mol) was introduced to the resultant green reaction mixture via a degassed stainless steel syringe at room temperature and the reaction mixture was heated at 110 oC for 12 hours. The tube was withdrawn from the oil bath and THF (10 mL) was added to the reaction flask. The reaction mixture was then passed through an silica gel column to remove the metal/ligand impurities. The polymer product was isolated by precipitation from a THF solution into excess methanol and dried under vacuum at 60 oC to give 1.89 g of • -bis(aminophenyl) functionalized polystyrene, (9) as a white solid: 1H NMR: δ = 1.22 – 2.45 ppm [m, polystyrene CH2 and CH], 3.62 ppm [broad s, 4H, 2 x NH2], 6.28 – 7.45 ppm [aromatic H]; FTIR (solid): 3412 cm-1 (N-H); Mn,theory = 4.5 x 103 g/mol; SEC: Mn = 4.10 x 103 g/mol, Mw/Mn = 1.11; Mn, titration = 4.35 x 103 g/mol.

Synthesis of • -Bis(aminophenyl) Functionalized Poly(methyl methacrylate), (10)

In a typical experiment, under argon atmosphere, copper (I) bromide (0.0504 g, 0.3510 x 10-3 mol), 2,2′-bipyridyl (0.1645 g, 1.0530 x 10-3 mol), (1-bromoethyl)-benzene (0.0650 g, 0.048 mL, 0.3510 x 10-3 mol), 1,1-bis(4-aminophenyl)-ethylene, (7) (0.074 g, 0.3510 x 10-3 mol) and diphenyl ether (1.0 mL) were added to a Schlenk tube. The tube was tightly sealed with a rubber septum and degassed by three freeze-pump-thaw cycles. The Schlenk tube was then immersed in an oil bath, preset at 90 oC. After 1 hour, freshly distilled methyl methacrylate (1.50 mL, 1.404 g, 0.0140 mol) was introduced to the resultant green reaction mixture via a degassed stainless steel syringe and the reaction mixture was heated at 90 oC for 12 hours. The tube was then withdrawn from the oil bath and THF (10 mL) was added to the reaction flask. The reaction mixture was passed through a silica gel column to remove the metal/ligand impurities. The polymeric product was isolated by precipitation from THF solution into excess methanol. The polymer product was filtered and dried under vacuum at 60 oC to give 1.76 g of • -bis(aminophenyl) functionalized poly(methyl methacrylate), (10) as a white solid: 1H NMR: δ = 3.69 ppm [broad s, 4H, 2 x NH2], 6.50 – 7.22 ppm [aromatic H]; FTIR (solid): 3469 cm-1 (N-H); Mn, theory = 4.0 x 103 g/mol; SEC: Mn = 3.60 x 103 g/mol, Mw/Mn = 1.18; Mn, titration = 3.85 x 103 g/mol.

Synthesis of • ,ω -Tetrakis(aminophenyl) Functionalized Polystyrene, (11)

A Schlenk tube was charged with copper (I) bromide (0.0525 g, 0.3660 x 10-3 mol), 2,2′-bipyridyl (0.1715 g, 1.098 x 10-3 mol), (1-bromoethyl)benzene (0.068 g, 0.050 mL, 0.3660 x 10-3 mol), 1,1-bis(4-aminophenyl)ethylene, (7) (0.80 g,
0.3660 x 10-3 mol) and diphenyl ether (1.7 mL). The tube was tightly sealed with a rubber septum and subjected to several freeze-pump-thaw cycles to remove oxygen. Under argon atmosphere, the Schlenk tube was then immersed in a thermostatically controlled oil bath at 110 oC. After 60 minutes, freshly distilled styrene (1.7 mL, 1.537 g, 0.0148 mol) was introduced to the resultant green reaction mixture via a degassed stainless steel syringe at room temperature and the reaction mixture was heated at 110 oC for 24 hours. An aliquot of the reaction mixture was removed and subjected to GC analysis to determine the presence of styrene in the reaction mixture. After complete consumption of styrene, as evidenced by GC analysis, 1,1-bis(4-aminophenyl)ethylene, (7) (0.1 g, 0.4756 x 10-3 mol) was added to the reaction mixture in the solid form at room temperature. The resultant reaction mixture was heated at 110 oC for 2 hours. The tube was then withdrawn from the oil bath, 10 mL THF was added to dissolve the reaction mixture and passed through a silica gel column to remove the catalyst and ligand impurities. The polymer product was isolated by precipitation from THF solution into excess methanol, filtered and dried under vacuum at 60 oC to give 1.90 g of • ,ω -tetrakis(aminophenyl) functionalized polystyrene, (11) as a white solid: 1H NMR: δ = 1.23 – 2.46 ppm [m, polystyrene CH2 and CH], 3.65 ppm [broad s, 8H, 4 x NH2], 6.24 – 7.44 ppm [aromatic H]; FTIR (solid): 3469 cm-1 (N-H); Mn, theory = 4.20 x 103 g/mol; SEC: Mn = 3.80 x 103 g/mol, Mw/Mn = 1.13; Mn, titration = 4.17 x 103 g/mol.

TABLE OF CONTENTS
TITLE PAGE
DECLARATION
ACKNOWLEDGEMENTS
ABSTRACT
TABLE OF CONTENTS
LIST OF FIGURES
LIST OF ABBREVIATIONS
CHAPTER 1 INTRODUCTION
CHAPTER 2 LITERATURE REVIEW
2.1 Chemical Modification of Polysulfone by Anionic Methods
2.2 Functionalization of Polymers with 1,1-Diarylethylene Derivatives
2.3 Free Radical Polymerization
2.4 Atom Transfer Radical Polymerization
2.5 Functionalized Polymers by ATRP
2.6 Supported Catalyst Systems for ATRP
CHAPTER 3 EXPERIMENTAL
3.1 Materials and Glassware
3.2 Characterization.
3.3 Anionic Synthesis of Functionalized Polysulfone
3.4 Atom Transfer Radical Polymerization: Synthesis of Amine Chain End Functionalized Polymers
3.5 A New Supported Catalyst System for the Atom Transfer Radical Polymerization of Styrene
3.6 Amine Functionalized Polymers by Atom Transfer Radical Polymerization: Polymerization Kinetics Studies
3.7 Synthesis of Polystyrene, (17) using Dipyridyl Functionalized Polysulfone, (3) as Ligand: Polymerization Kinetics Studies
CHAPTER 4 RESULTS AND DISCUSSION
4.1 Chemical Modification of Polysulfone by Anionic Methods
4.2 Atom Transfer Radical Polymerization: Synthesis of Chain End Functionalized Polymers.
4.3 Synthesis of Primary Amine Functionalized Polymers by Atom Transfer Radical Polymerization
4.4 Synthesis of Tertiary Amine Functionalized Polymers by Atom Transfer Radical Polymerization
4.5 Synthesis of Amine Chain End Functionalized Polymers by Atom Transfer Radical Polymerization: Polymerization Kinetics Studies
4.6 A New Supported Catalyst System for the Atom Transfer Radical Polymerization of Styrene
CHAPTER 5 CONCLUSION
5.1 Chemical Modification of Polysulfone by Anionic Methods 121
5.2 Atom Transfer Radical Polymerization: Synthesis of Amine Chain End Functionalized Polymers
5.3 A New Supported Catalyst System for the Atom Transfer
Radical Polymerization of Styrene
REFERENCES
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