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A magnetic nano-supported Cu(I) catalyst was prepared and showed high activity for cyclization of ene-yne-ketone to synthesize furans. The catalyst was easily recovered from the reaction by using external magnets and reused 8 times without significant loss of its catalytic activity.

A novel superabsorbent polymer composite was synthesized by graft copolymerization of cottonseed protein and acrylic monomers in order to explore the new application of cottonseed protein in nonfood field. This composite was synthesized by solution based copolymerization, using partly neutralized acrylic acid, acrylamide and cottonseed protein as raw material, N,N-methylene bisacrylamide as crosslinking agent, potassium persulphate and sodium sulfite as the initiators. The effects of the certain variables of the copolymerization on the water absorbency of the synthesized composite were measured. The chemical structure of the composite was characterized by means of Fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetry analysis. The swelling properties of the composite were carried out under varying pH conditions. Further, the saline sensitivity, swelling kinetics and water retention ability of the composite was investigated. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

Temperature-sensitive interpenetrating polymer network (IPN) hydrogels based on soy protein and poly(N-isopropylacrylamide) were successfully prepared. The structure and properties were systematically characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry and thermogravimetric analysis, and the swelling and deswelling behavior was also investigated. It was found that the hydrogels had good miscibility, thermal stability and temperature sensitivity, and the lower critical solution temperature was ca 32 °C. Changing the content of soy protein or crosslinker could be used to control the swelling behavior, water retention and network structure of the IPN hydrogels. The results show that the novel IPN hydrogels may be of potential interest in drug delivery systems. Copyright © 2011 Society of Chemical Industry

A series of the thermosensitive interpenetrating polymer network hydrogels composed of soy protein and poly(N-isopropylacrylamide) were successfully prepared. The structure and properties were systematically characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry. It was found that the hydrogels had good miscibility and high porosity, and the volume phase transition temperatures of the hydrogels were around 32°C. The release behavior and the release mechanism of a model protein, bovine serum albumin (BSA), were also investigated in detail. The results indicated that the release behavior of BSA had strong temperature dependence and the release percentage of BSA could be controlled by modulating the amount of soy protein or crosslinking agent. The analysis of the release mechanism revealed that the Fickian diffusion controlled release was dominant under the experimental conditions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.

Copolymers of poly(silphenylene–siloxane) with dimethylsiloxane and diphenylsiloxane with various end groups were synthesized through an SiH/SiOR polycondensation process. The thermooxidative degradation behaviors of the copolymers were investigated by thermogravimetric analysis and IR spectrometry techniques. All of the polymers were characterized by a two-step mass loss. The first one, which peaked at 510–545°C in differential thermogravimetric curves, was mostly caused by the main-chain depolymerization, whereas the second one, which reached its maximum around 650°C, was caused by side-group oxidation and SiC bond scission. The main-chain depolymerization occurred over a temperature range of some 470–580°C, whereas SiC bond scission and side-group oxidation occurred over a temperature range of about 585°C to above 720°C. The incorporation of phenyl groups in the end groups greatly retarded the temperature for the degradation onset of the main chain to 120°C higher. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Most acrylic acid-based superabsorbent hydrogels, which have been widely used in many applications, are crosslinked with water-solvable crosslinker N,N-methylenebisacrylamide (NMBA), which is easy to hydrolyze when radiated by ultraviolet, leading to decomposition of the superabsorbent hydrogels. In this article, ultraviolet-induced decomposition of acrylic acid-based superabsorbent hydrogels crosslinked with NMBA was investigated by weight loss method under ultraviolet radiation. The results showed that the decomposition rate of the superabsorbent hydrogels was controlled by ultraviolet-induced activation of amide groups on the networks when the intensity of ultraviolet radiation was low, whereas it was controlled by hydrolysis of amide groups on NMBA molecules when the intensity of ultraviolet radiation was high. The ultraviolet stability of acrylicacid-based superabsorbent hydrogels crosslinked with NMBA can be improved by increasing the neutralization degree of acrylic acid, increasing the dosage of crosslinker NMBA, or introducing acrylamide as comonomer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

This work examines the interfacial structure and interaction between water and polymer chains in the hydrogel–hydrogel composites with the goal of establishing foundations for further investigation of drug diffusion from one hydrogel to another in the soft contact lens. This is based on the ability of the hydrogel–hydrogel composites to release ophthalmic drugs in a sustained manner. The hydrogel–hydrogel composites were synthesized by immersing the glycerol-swollen particles of crosslinked N-vinyl-2-pyrrolidone (NVP) into the monomer of hydroxyethylmethacrylate (HEMA) containing initiator benzoylperoxide (BPO) that polymerizes to form a matrix in the presence of the first networks. The hydrogel–hydrogel composites were characterized by UV/Vis spectrophotometer, scanning electronic micrography (SEM), and differential scanning calorimetry (DSC). The results showed that the samples of hydrogel–hydrogel composites of the particles of crosslinked NVP and poly-HEMA were transparent and glassy and suitable for soft contact lens. Three types of the interfacial structure, no interpenetrating interface, partly interpenetrating interface, and fully interpenetrating interface, of the hydrogel–hydrogel composites existed, and the type of the interfacial structure was determined by the degree to which the monomer of HEMA penetrated into the first networks before formation of the matrix. Different from poly-HEMA hydrogels, the peaks near 0°C on DSC curves of the hydrogel–hydrogel composites did not split while they were kept acute, and the amount of freezable-bound water was less. This shows that the water incorporated in the hydrogel–hydrogel composites does not strongly interact with polymer matrix, so the hydrogel–hydrogel composites cannot keep their shape during the phase transition of water. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The employed catalyst can be easily recovered from the reaction by external magnets and reused eight times without significant loss of its catalytic activity.

As a nanoparticle support material, carbon nanotubes (CNTs) provide a certain potential activation of catalysis in heterogeneous catalytic organic reactions. Herein, an efficient Ag/CNT-catalyzed synthesis of enamines via hydroamination of activated alkynes with aromatic amines has been described. This catalyst still retains catalytic activity after being recycled and reused three times. In addition, it represents a green and environmentally friendly process for preparation of enamines. Copyright © 2013 John Wiley & Sons, Ltd.

E-mail: cuigdut@yahoo.com.cnReceived April 8, 2013, Accepted May 13, 2013A convenient Rh-catalyzed C-H arylation of imidazo[1,2-a]pyridines with a variety of aryl halides or triflateshas been reported. This process afforded a range of biaryl compounds in excellent yields and showed highactivity and broad scope. Key Words : Rhodium catalyst, Aryl halides, Regioselective arylation, Imidazo[1,2- a]pyridines, TriflatesIntroductionHeteroaromatics bearing aryl-heteroaryl bond are alwaysas one of the most important structural units frequentlyfound in biological compounds, natural products, materialschemistry, ligands.

pH- and temperature-responsive interpenetrating polymer network (IPN) hydrogels based on soy protein and poly(N-isopropylacrylamide-co-sodium acrylate) were successfully prepared. The structure and properties of the hydrogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analyzer. The equilibrium and dynamic swelling/deswelling behaviors and the drug release properties of the hydrogels responding to pH and/or temperature were also studied in detail. The hydrogels have the porous honeycomb structures, good miscibility and thermal stability, and good pH- and temperature-responsivity. The volume phase transition temperature of the hydrogels is ca. 40°C. Changing the soy protein or crosslinker content could be used to control the swelling behavior and water retention, and the hydrogels have the fastest deswelling rate in pH 1.2 buffer solutions at 45°C. Bovine serum albumin release from the hydrogels has the good pH and temperature dependence. The results show that the proposed IPN hydrogels may have potential applications in the field of biomedical materials such as in drug delivery systems. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39781.

3,3′-Bis(5,6-dibromomethyl-1,2,4-triazine), a new polyfunctional bipyridine analogue for constructing supramolecular structures, has been synthesized from 2,3-butanedione and oxylhydrazidine by two routes in moderate to high yields.

Hydrogels were synthesized from poultry feather protein by crosslinking ethylene diamine tetraacetic dianhydride (EDTAD)-modified feather protein isolate (FPI) with glutaraldehyde (Glu). Different molar ratios of EDTAD/FPI were used to obtain FPI of different degrees of acylate modification. Differential scanning calorimeter measurements of glass transition temperature suggested that hydrogel formation was based on the hydrogen bond between EDTAD-modified FPI segments. The swelling properties of modified FPI hydrogel were investigated in deionized water and in solutions of different salt contents (i.e., ionic strengths) and pH. An optimal swelling ratio (SR) of 63 g/g was obtained when molar ratios of EDTAD/FPI and Glu/FPI were 0.12 and 0.008, respectively. SR decreased substantially with increase in ionic strength, and at a given ionic strength, SR increased with solution pH in 4.0 to 10.0 range. The water transport mechanism of the hydrogel was also pH dependent and was controlled by Fickian diffusion and polymer relaxation. At higher pH value, the water transport profile became more dependent on polymer relaxation than at lower pH. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010