Study On The Synthesis And Characterization Of β-cyclodextrin Polyurea Pseudorotaxane And β-cyclodextrin Poly(Schiff Base)s Pseudorotaxane

At the present, supramolecular chemistry is a new advancing subject which has increasingly become the focus of chemists. Rotaxane/pseudorotaxanes as an important branch of supramolecular chemistry attracts more attention. CD-rotaxane/pseudorotaxanes have opened up a new way in the polymer solubilization and polymer processing. At the same time, polyurea rotaxane/pseudorotaxanes and poly (Schiff base) rotaxane/pseudorotaxanes in whichβ-cyclodextrin as "rotor" are introduced have not been reported.In this paper eight types ofβ-cyclodextrin (β-CD) polyurea-rotaxane are synthesized through the first-inclusion and post-polymerization (polymerization) technique, but fourteen types ofβ-CD poly (Schiff base) pseudorotaxanes are synthesized through the first- polymerization and post-inclusion (inclusion) technique.(1) Two types ofβ-CD polyurea pseudorotaxanes were synthesized through the inclusion complex ofβ-CD with aromatic diamines and aromatic diisocyanates (1:1 molar ratio);(2) Four types ofβ-CD polyurea pseudorotaxanes were synthesized through the inclusion complex ofβ-CD with aromatic diamines, aromatic diisocyanates and extender with a large group (molar ratio 1:2:1);(3) Two types ofβ-CD polyurea pseudorotaxanes were synthesized through the inclusion complex ofβ-CD with aromatic diamines, aromatic diisocyanates and terminator (molar ratio 1:1.3:0.2);(4) Ten types ofβ-CD poly (Schiff base) pseudorotaxanes were synthesized through adding the NMP solution of poly (Schiff base) to the saturated aqueous solution ofβ-CD.The all types ofβ-CD pseudorotaxanes were characterized primarily by means of infrared spectroscopy (FTIR), thermogravimetry (TG), 1H-nuclear magnetic resonance (1H NMR), X-ray powder diffraction(XRD), differential scanning calorimetry (DSC) and field emission scanning electron microscope (FESEM).β-CD content of polyurea pseudorotaxanes was calculated by 1HNMR data and compared with the results obtained from TG curves. The results show that: these types of pseudorotaxanes are supramolecular systems, which are caused by backbone polymer andβ-CD through the interaction of non-covalent. The yield of the pseudorotaxanes and the contents ofβ-CD in the pseudorotaxanes by (3) are highest, following by (2) and by (1). In addition, the activity of isocyanate and the position of isocyanate on phenyl ring also affect the yield and the contents ofβ-CD in the pseudorotaxanes. Four types of water-solubleβ-CD-Schiff base pseudorotaxanes were synthesized by (4), two of polyurea pseudorotaxanes by (2) are nano-materials, and a polyurea rotaxane by (3) is a crystal. The introduction ofβ-CD partially changes the physico-chemical properties of poly (Schiff base) and polyurea, such as thermal stability, water-soluble and crystalline.The process of synthesizing ofβ-CD pseudorotaxanes is simple and environmentally friendly, and these broad the scope of their application. There is a large number of hydroxyl on theβ-CD pseudorotaxanes chains that provides a way to further modified theβ-CD pseudorotaxanes. Present study focuses on the modification of polymer materials, such as poly (Schiff base) and polyurea, which helps further exploring the unknown areas of the supramolecular chemistry and polymer science.