摘要:<正> Fluorescence properties of a series of styrene/p-divinylbenzene (St/p-DVB) copolymer beads were investigated by steady-state fluorescence spectra. In addition to the fluorescence of the phenyl ring excimer, a new emission band at ca 395nm appears when p-DVB content in feed is higher than 13%(wt). The intensity of this new emission was found to change with pDVB content and to decrease with swollen beads. The origin of this new emission is considered to be a multi-ring excimer formation.
摘要:<正> The amidoximation process of commercial polyacrylonitrile fiber was studied. The results showed that it is possible to prepare a chelating fiber, which present high adsorption capability to Au3+ and reasonable mechanical property, by the amidoximation of PAN fiber, with the increase of reaction time or agent concentration, the coversion of CN group in PAN increases rapidly at first and then increases slowly. When the reaction temperature is higher than that at which the paracrystalline region in the fiber is destroyed, the conversion of CN group increases greatly, but the mechanical property of the fiber begins to be inferior.
摘要:<正> The self-diffusion of RE isotopes in porous cation exchangers with various particle size and in several MR-type resins in EDTA solutions of rare earths was studied. The intraparticie effective diffusivities De of Ce, Tb and Yb were measured by isotopic ion exchange, De was affected by the concentration of the bulk solution and was separated into a solid phase diffusivity Dg and a macropore diffusivity Dp using Kataoka’ s didisperse pore model. It shows that the model can be applied to express the kinetic process; De much larger than De and Dg is nearly equal to De. Solid phase resistance is a major component of resistance to the exchange for porous resins.
摘要:<正> This paper describes the preparation of polystyrylsulfonyl chloride, a reactive intermediate, and its application in syntheses of functionalized polymers which can be used in organic chemistry as polymeric reagents, supports and in controlled release systems.
摘要:<正> Four kinds of palladium catalysts dispersed on poly-N-vinyl-2-pyrrolidone were prepared by using CH3OH-NaOH, NaBH4, H2O or CH3OH-H2O as the reducing agent in the process of catalyst preparation. The catalysts were characterized by XPS, TEM, XRD and used for the hydrogenation of methyl acrylate. It was found that the valence state of palladium and distribution of palladium particles as well as the hydrogenation rate were greatly affected by the reducing agent. The best evenly dispersed palladium catalyst showing high hydrogenation activity was prepared using CH3OH-NaOH as the reducing agent.
摘要:<正> In search of a suitable adsorbent used for the enrichment and separation of natural saponins from an aqueous solution, a series of porous cross-linked poly (vinylacetophenone) resins Ⅰ-Ⅸ were synthesized via the. Friedel-Crafts acylation of styrene-divinyl-benzene copolymer beads. Their carbonyl contents were characterized by infrared spectra and elemental analysis. Their physical properties such as bulk densities, skeleton densities, and specific surface areas were also determined. The tests for the resins adsorption of gypenosides showed that only those resins with high carbonyl contents and large specific surface areas could favorably adsorb gypenosides from an aqueous solution with much higher capacities.