Novel Me-β-CD Inclusion Complex Functionalized And Its Applications In Polymer

The demand for environmentally benign processes is growing as the world becomes increasingly aware of environmental issues involving conventional organic solvents. The complexation of cyclodextrin provides an efficient way promising to obtain the water-soluble product directly from the wide varies of commercially available organic soluble compounds, but without any chemical modification.1. Me-β-CD was used to complex the photoinitiator 2,2-Dimethoxy-2-phenyl acetophenone(DMPA), yielding a water-soluble host/guest complex(IC-1), and the ratio of host/guest was 2:1. The comparative studies demonstrated that the Me-β-CD complexed DMPA exhibited a high photoreactivity identical to the uncomplexed DMPA, while the CD complex can influence the reaction process due to the steric effect of CD. The photopolymerization rate of acrylamide can be described by the equation: Rp=K[2a]0.62[M]1.37[I]0.5[Me-β-CD]0, the reaction mechanism was suggested and the quantum efficiency of the polymerization was calculated.2. A water-soluble and photoactive inclusion complex (IC-2) has been obtained by the complexation of Me-β-CD with the hydrophobic 4,4'-dimethyl diphenyliodonium salt (DPI), the ratio of host/guest was 2:1, and the association constant was 9.2×104 (L/mol)2. The enhanced photochemical reactivity of DPI was observed, and the acid-photogeneration in the comparative experiments due to H-donor effect of CD. The rate of photosensitized electron transfer improved also due to the adjacent effect of CD complexation. The polymerization results demonstrated the photosensitized IC-2 was an effectively water-soluble initiating system.The two typical examples above indicated that the complexation of CD provides a way to make a lot of water-soluble products.3. The water-soluble photoactive supramolecular Me-β-CD complex IC-3 was prepared in which photoabsorber (FL) and initiator (DPI) are combined together. The formation and interaction of the ternary complex was investigated through the steady-state fluorescence spectra and dynamic-state spectra, found that the fast static-quench and slow dynamic-quench existed together, but there was only static-quench in the film, and the quenching effect increased with the complex formation. Applied the modified Stern-Volmer equation to analysis the complex formation, the association constant Ka was 145 L/mol.The photochemical reaction of IC-3 was studied and found that the electron transfer and the subsequent photochemical reaction rates and quantum efficiency between the donor FL and acceptor DPI in the film all depended on the quantity of the formed IC-3. The photochemical reaction obeys the intramolecular electron transfer in S1 state and possesses high reactivity and radical formation efficiency. The photopolymerization experiments of IC-3 demonstrated that the conversions could reach the maximum less than 10 s.The two-photon initiating photopolymerization was also investigated in the film. The microstructures with line widths 500 nm were obtained from the water developing photocrosslinking system by the femtosecond laser scanning process. The results indicated that the shortcoming of small two-photon absorption cross-section of the commercial two-photon initiator could be compensated with the increased radical formation efficiency, which exploited a new way to develop the commercially water-soluble two-photon initiating system.4. Utilize Me-β-CD as the host to complex the hydrophobic monomer POEA yielding the water-soluble host/guest complexes. A series of hydrophobically modified cationic co-polymers P(AM/DMC/POEA) were designed and synthesized. The flocculation and absorptive experiments demonstrated that the flocculation and absorptive properties can be increased effectively by the hydrophobic interaction. The results indicate the co-polymerization of hydrophobic monomer and hydrophilic monomer in a homogeneously system provides a way to obtain amphiphilic and functional polymers.5. A supramolecular recognization system was constructed based on the water-solubleβ-cyclodextrin polymer (β-CDE) as host and hydrophobically modified polyacrylamide P(AM/POEA) as guest. The results of 1H NMR and 2D-NOESY measurements indicated that the host-guest interaction betweenβ-CDE and P(AM/POEA) was carried out through the formation of inclusion complexes between cyclodextrin cavity and the hydrophobe POEA. High viscosity enhancements were observed whenβ-CDE was added to P(AM/POEA) solutions which can be controlled by varying the hydrophobe content and environmental conditions. The TEM images demonstrated that the host-guest interaction betweenβ-CDE and P(AM/POEA) led to the formation of multi-polymeric aggregate with solid sphere structure. These results indicated that it was a valuable way to vary the rheological property of the solution through the host/guest interaction.