Sulfonamide as an Activating Group for the Synthesis of Poly(aryl ether sulfonamide)s by Nucleophilic Aromatic Substitution

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• 作者：Nathaniel T. Rebeck ; Daniel M. Knauss
• 刊名：Macromolecules
• 出版年：2011
• 出版时间：September 13, 2011
• 年：2011
• 卷：44
• 期：17
• 页码：6717-6723
• 全文大小：791K
• 年卷期：v.44,no.17(September 13, 2011)
• ISSN：1520-5835

文摘

Poly(aryl ether sulfonamide)s were produced utilizing the sulfonamide moiety as a new activating group for nucleophlic aromatic substitution polymerization. The activated monomer, 2,4-difluoro-N,N-dimethylbenzenesulfonamide, was synthesized in high yields through a simple substitution reaction between 2,4-difluorobenzenesulfonyl chloride and dimethyl amine. The reactivity of this monomer in a nucleophilic aromatic substitution mechanism was estimated using semiempirical calculations at the PM3 level, as well as by ¹H, ¹³C and ¹⁹F NMR spectroscopy. The data support the sulfonamide as sufficiently electron-withdrawing to activate aryl fluorides for substitution by phenoxide nucleophiles. Model reactions with tert-butylphenol confirm that the aryl fluorides of 2,4-difluoro-N,N-dimethylbenzenesulfonamide can be displaced in quantitative yields and suggest the process is suitable for forming polymers. A variety of novel polymers were produced employing bisphenol A, 4,4鈥?biphenol, bisphenol AF and hydroquinone as comonomers. The polymers were characterized by gel permeation chromatography, solution viscometry, NMR spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The high molecular weight poly(aryl ether sulfonamide)s exhibit moderate to high glass transition temperatures ranging from 163 to 199 掳C. The polymers were shown to be thermally stable with 5% weight loss occurring from 398 to 442 掳C in a nitrogen atmosphere.