Grafting of living poly(ethylene oxide) onto polystyrene via aromatic nucleophilic displacement of activated nitro groups

Shalati, Mohamad D.; Overberger, C. G.

doi:10.1002/pol.1983.170211207

Cited by 8 publications

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References 19 publications

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“…Displacement of a nitro group has also been used to graft "living" PEG to nitro-substituted polystyrene in the preparation of graft copolymers. 43 Not only is SnAt displacement of a variety of groups (Cl, F, NO2, etc.) the standard procedure for the syntheses of aromatic polyether sulfones, polyether ketones, and polyetherimides,44 as well as polyalkyl aryl ethers,45 but has also been used to end-cap polyether ketones with arylethynyl termini, suitable for later cross-linking of the polymer.46 Although the mechanism of these A<wB-0, S, S02, CO, CHj, QCHjh, N-N, N-N R or R' = CH3, CH2CH3, Ph, NO, Sequence 5 polymerizations and derivatizations has been taken to be SnAt43-46 there is recent evidence that the SrnI mechanism may compete when less activated substrates are used in the polymerization.…”

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confidence: 99%

Rationalizing the Regioselectivity in Polynitroarene Anionic .sigma.-Adduct Formation. Relevance to Nucleophilic Aromatic Substitution

Buncel¹,

Dust²,

Terrier³

1995

Chem. Rev.

235

144

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ContentsJuliars Dust completed his B.Sc.(Hons) in 1978 at the University of Waterloo, in southwestern Ontario, but then traveled east to Mt. Allison University, where he studied free radical chemistry of stericaliy-hindered aromatics with Professor Ross Barclay. In 1982 he traveled farther east to Dalhousie University where, under the guidance of Professor Don Arnold, he received a M.Sc. for a thesis that defined the «*n substituent scale for benzylic radicals. Changing direction, Dust moved west to Queen's University, and as a student of Professor Erwin Buncel, commenced a study of Meisenheimer complexes, including those formed by novel ambident polynitroheteroaromatics (i.e. super-electrophiles). This research led to a Ph.D. in 1987 and it continues to be a focus ot his effort. His postdoctoral work at University of Alabama in Huntsville with Professor Milton Harris sparked another continuing interest: preparation, application, and mechanistic investigation ot polyethylene glycol) derivatives. In 1989 he settled in Corner Brook, the western-mosl city in the eastern-most province in Canada, Newfoundland. There he accepted an Assistant Professorship at Sir Wilfred Grenfell College (Memorial University); he was granted tenure in 1994 and was promoted lo the rank of Associate Professor in 1995.

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confidence: 99%

Rationalizing the Regioselectivity in Polynitroarene Anionic .sigma.-Adduct Formation. Relevance to Nucleophilic Aromatic Substitution

Buncel¹,

Dust²,

Terrier³

1995

Chem. Rev.

235

144

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Facile Synthesis of Amphiphilic Heterografted Copolymers with Crystalline and Amorphous Side Chains

Gao

Wang

Ren

et al. 2013

Macro Chemistry & Physics

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An amphiphilic polymer brush with PB and PEO side chains is prepared by combined “grafting‐onto” and “grafting‐from”. The linear and star‐shaped heterografted copolymer synthesized is of controlled molecular weight and has a narrow molecular weight distribution (Mw/Mn < 1.2). A DSC study of this heterografted copolymer containing crystalline and amorphous chains shows that it displays “fractionated crystallization” behavior. The study on isothermal crystallization kinetics of the copolymer is carried out in isothermal step crystallization (ISC) experiments, in which two crystallization exothermic peaks at low temperatures are observed. The critical micelle concentration (cmc) of the amphiphilic brush polymer in an aqueous solution is determined by a fluorescence technique. The results show that this amphiphilic brush forms aggregates in the system.magnified image

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Syntheses and polymerizations of some vinyl monomers containing nitro‐ or fluorophthalimides

Overberger

Shalati

1983

J. Polym. Sci. Polym. Chem. Ed.

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Synopsis 4-Nitro-N-vinylphthalimide (4) was synthesized by two different procedures. Compound 4 was not polymerizable or copolymerizable by AIBN. Poly(N-vinylphthalimide) (17) was prepared and partially nitrated at 10-25°C. N,"-(1,2-Ethanediyl)bis(4-nitrophthalimide) (15) and NW-(1,3-propanediyl)bis(4-nitrophthalimide) (16) were prepared by the condensation of the corresponding diamine with phthalic anhydride followed by nitration of the condensation products. 4-Nitrophthalic anhydride was prepared by the hydrolysis of 15. Four styrene-substituted phthalimide monomers were synthesized. These include N-(4-vinylphenyl)phthalimide (25a), N-(4-vinylphenyl)-3-fluorophthalimide (25b), N-(4-vinylphenyl)-3-nitrophthalimide (25c ), and N-(4-vinylpheny1)-4-nitrophthalimide (25d). Monomers 25a and 25b were polymerized by freeradicd initiator (AIBN), whereas monomers 25c and 25d were not polymerizable or copolymerizable by AIBN due to a strong inhibitive effect exerted by the nitrophthalimide group. Monomers 25c and 25d were cationically polymerized (BFrOEt2). Monomer 25b and styrene were copolymerized and their reactivity ratios were rl = 1.7 and r2 = 0.55, respectively. The prepared polymers are useful as backbone polymers for grafting living anionic polymers. EXPERIMENTALAll melting points were determined in open capillary tubes on a Thomas Hoover Capillary Melting Point Apparatus and are uncorrected. Elemental analyses were performed by Spang Laboratories, Eagle Harbor, Michigan, or by Galbraith Laboratories, Inc., Knoxville, Tennessee. All viscosity measurements were carried out at 25.0°C using Cannon-Ubbelohde Semi-Micro dilution viscometers. UV spectra were recorded on a Perkin-Elmer Model 402 spectrophotometer; IR spectra were recorded on a Perkin-Elmer Model 257 spectrophotometer. NMR spectra were recorded on a Varian T-60 and on a Jasper Electronic Optics Laboratories (JEOL) 100 MHz NMR spectrophotometer. All solvents were of high purity (99.9%) and distilled before use. All other reagents were used as received. N-(2-Hydroxyethyl)-4-Nitrophthalimide (2)4-Nitrophthalimide was prepared according to the literaturelo in 53% yield. The procedure described for the preparation of N-(2-hydroxyethy1)phthalimide in the patent literaturell was adopted here in the following manner. 4-Nitrophthalimide (95.5 g, 0.5 mol), 4-methyl-2-pentanone (300 mL, and chromium tris(2-ethylhexanoate) (1.0 g) were placed in a 1 L autoclave. The mixture was cooled in a dry ice bath and ethylene oxide (26.5 g, 0.6 mol) was added. The autoclave was closed and placed in the oil bath which was then heated to 160-165OC for 2 h. The reaction mixture was allowed to cool to room temperature overnight and the excess ethylene oxide was released.* The solvent was evaporated under reduced pressure and the yellow residue was crystallized from ethanol-acetone to give 112.0 g pale yellow crystals (95% yield) of pure N42hydroxyethyl)-4-nitrophthalimide; m.p. 112-114OC. ANAL. Calcd for CloHsN205: C, 50.85; H, 3.41; N, 11.86. Found C, 50.87; H, 3.42; N, 11.80. NM...

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Grafting of living poly(ethylene oxide) onto polystyrene via aromatic nucleophilic displacement of activated nitro groups

Cited by 8 publications

References 19 publications

Rationalizing the Regioselectivity in Polynitroarene Anionic .sigma.-Adduct Formation. Relevance to Nucleophilic Aromatic Substitution

Rationalizing the Regioselectivity in Polynitroarene Anionic .sigma.-Adduct Formation. Relevance to Nucleophilic Aromatic Substitution

Facile Synthesis of Amphiphilic Heterografted Copolymers with Crystalline and Amorphous Side Chains

Syntheses and polymerizations of some vinyl monomers containing nitro‐ or fluorophthalimides

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