Aqueous radical polymerization of N,N-dimethylacrylamide redox-initiated by aerobically catalytic oxidation of water-soluble tertiary amines

作者：Wang Xiuting; Sun Xiang; Zhai Guangqun^*

来源：Polymer Bulletin, 2015, 72(11): 2809-2829.

DOI：10.1007/s00289-015-1437-x

• N,N-Dimethylacrylamide (DMAAm)
• Aerobically catalytic oxidation
• Radical polymerization
• Tertiary amine
• Alpha-amino functionality
• Mono-centered redox-initiation

Catalytic oxidation of water-soluble tertiary amines by complexes of Cu-II, Fe-III and Co-II was utilized to initiate radical polymerization of N,N-dimethylacrylamide (DMAAm) in aqueous solution at 70-80 A degrees C. The oxidation of tertiary amines by Cu-II was studied by proton nuclear magnetic resonance spectroscopy and online ultraviolet-visible spectrophotometry. The polymerization kinetics was monitored by gas chromatography, and molecular weight of the PDMAAm was measured by gel-permeation chromatography coupled with multi-angle laser light scattering. Oxidation of tertiary amines occurs predominantly via formation of C-alpha center dot radicals to initiate polymerization of electron-deficient monomers and N-dealkylation, and redox equilibrium between Cu-I/L and Cu-II/L is established at a faster rate in aqueous media. Fe-III and Cu-II complexes are efficient catalysts as each catalyst molecule could generate above 10 propagating radicals in 5 h, while Co-II complex might involve in oxidation of tertiary amines in non-radical pathway, leading to a low catalytic efficiency. Water-soluble tertiary amines such as N,N-dialkylethanolamine (alkyl = methyl, ethyl etc.) are reducing agents of a higher activity in aqueous media than those primary or secondary analogues. Our strategy renders it possible to prepare polymer of alpha-amino functionality via one-pot process from commercially available commodity reagents under practical conditions with negligible catalyst residue.

• 出版日期2015-11
• 单位常州大学