title: Study on the heterogeneous degradation of chitosan with H(2)O(2) catalyzed by a new supermolecular assembly crystal: [C(6)H(8)N(2)](6)H(3)[PW(12)O(40)].2H(2)O.
abstract: A new supermolecular assembly crystal, [C(6)H(8)N(2)](6)H(3)[PW(12)O(40)].2H(2)O (DMB-PWA), was synthesized with phosphotungstic acid (PWA) and 1,2-diaminobenzene (DMB) under hydrothermal conditions and was characterized by Fourier-transform infrared spectra (FTIR) and single-crystal X-ray diffraction analysis. DMB-PWA could effectively catalyze oxidative degradation of chitosan with H(2)O(2) in the heterogeneous phase. The optimum degradation conditions were determined by orthogonal tests as follows: amount of chitosan 1.00 g, 30% (wt %); H(2)O(2), 3.0 mL; dosage of catalyst, 0.06 g; reaction temperature, 85 degrees C; and reaction time, 30 min. The water-soluble chitosan with a viscosity-average molecular weight (M(v)) of 4900 was obtained under the optimum degradation conditions and was characterized by FTIR, ultraviolet-visible diffuse reflection spectra (UV-vis DRS), and X-ray powder diffraction analysis.
authors.affiliation: College of Chemistry and Pharmacy Engineering, Nanyang Normal University, 1638(#) Wolong Road, Nanyang, Henan Province 473061, PR China.
authors.forename: Qun Zeng
authors.initials: QZ
authors.lastname: Huang
authors.forename: Zhao Hui
authors.initials: ZH
authors.lastname: Meng
authors.forename: Yu Quan
authors.initials: YQ
authors.lastname: Feng
authors.forename: Heng Zhen
authors.initials: HZ
authors.lastname: Shi
mesh_terms: D002384:Catalysis; D048271:Chitosan / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010655:Phenylenediamines / Q000737:chemistry*; D010772:Phosphotungstic Acid / Q000737:chemistry*; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D010655:Phenylenediamines; D014867:Water; D010772:Phosphotungstic Acid; C034193:1,2-diaminobenzene; D048271:Chitosan; D006861:Hydrogen Peroxide