Synthesis And Property Studies Of DMAP Functionalized Polyacrylonitrile Fiber

DMAP (4-dimethylaminopyridine) is often used as a catalyst for its strongnucleophilicity, and it performs an excellent catalytic property in most reactions. Thismakes it become one of the catalysts used frequently in the organic synthesis.However, easy loss, difficult recovery and exorbitant price are the defects difficult toovercome. It’s attractive for chemists to find a catalyst which is easy to reuse andrecycle in recent years. N,N’-dimethyl-N-(4-pyridyl)-1,3-propanediamine(DMAPanalogue) was grafted onto the surface of the polyacrylonitrile fiber（PANF）in thisarticle to design a DMAP functionalized polyacrylonitrile fiber (PANDMAPF), and thecatalytic property was studied in detail.Polyacrylonitrile fiber was used as the material to synthesize PANDMAPF, and thesynthesis conditions were optimized in this article. Infrared spectroscopy (FTIR),scanning electron microscope (SEM) and elemental analysis were used to characterizeit.Catalytic experiment showed that PANDMAPF can be used to efficiently catalyze athree components reaction among aldehyde, malononitrile and naphthol in water toafford the corresponding substituted2-amino-2-chromenes. And the nuclear magneticresonance (NMR) was employed to characterize the structure of the compounds.20mol%catalyst amount and1h reaction time are the optimization result. The reactioncan proceed in both ethanol and water with a lower yield of81%and72%respectively. It is worthwhile to note that the PANDMAPF exhibits excellent catalyticactivities in water and methanol, but failed to show any catalytic activity in ethanoland other solvent with low polarity, that is, water can turn on the reaction but ethanolshut it off in the presence of PANDMAPF. This extremely differs from the same reactioncatalyzed by DMAP or a tertiary amine functionalized polyacrylonitrile fiber. It wasclarified that the PANDMAPF is applicable to a wide range of aromatic aldehydes(80-99%). Moreover, this newly prepared fiber catalyst was also confirmed to performexcellent reusability and recyclability (seven times) without other post-process.Metal ions adsorption result displayed that various metal ions can be adsorbedon the PANDMAPF and PANDMAPF turned to the colors of the intrinsic color of themetal ions. However, the saturated adsorption amount is relatively low as the complexation ability of the ring of pyridine is weak. But this result proved thatsome kind of pyridine derivatives functionalized fiber has the ability to adsorbmetal ions in a large of quantity.