Xue Gang Luo

Graft Copolymerization of Soybean Protein Isolated and Methyl Acrylate as a New Thermoplastic Material

New thermoplastic soy protein isolated (SPI) and methyl acrylate (MA) copolymers (T-SPI-g-MA) were prepared using graft copolymerization and initiated with ammonium persulfate (APS). The reaction conditions such as initiator concentration and temperature on the graft percentage (GP) were investigated. The single factor experimental showed that the optimal conditions for grafting of 15g SPI were: 4 g initiator of APS, 60 mL monomer of MA and in 250 mL 2M urea aqueous solution at 70 °C for 3 hours. The products were characterized by means of FT-IR and DSC. The results indicated that the monomer was grafted successfully on SPI and the T-SPI-g-MA had a glass transition at 22 °C.

Preparation and Characterization of Spherical Lignin/Polylactide Composite Adsorbent

The spherical lignin/polylactide (PLA) adsorbent was prepared by solvent evaporation. The dispersed phase contents, the PLA concentration and ratio of PLA to lignin on the diameter and mechanical strength of the PLA/lignin composite adsorbent spheres were investigated and the morphology structure and mechanical strength of the adsorbent were characterized by scanning electron microscope (SEM) and dynamic mechanical analyzer (DMA). The results showed that the adsorbent has porous structure, and the mechanical strength increased significantly as the ratio of PLA to lignin as 4:1.

Adsorption of Ag+ from Aqueous Solutions by Rice Husk

This paper reports the feasibility of using rice husk to remove Ag+ from synthetic wastewater. Effect of various adsorption parameters, namely, pH, adsorbent dose, initial silver concentration and contact time has been studied in batch systems. The results indicated that rice husk offered high removal efficiency, fast adsorption rate and high uptake capacity for Ag+ ions. The equilibrium was attained within 20 min and the maximum removal efficiency at 11g/L rice husk and at pH 2 was found to be 99.76%. The kinetic data was fitted well to pseudo-second order model. The isotherm adsorption data was well described by the Langmuir isotherm model and the maximum uptake capacity of Ag+ ions onto rice husk was found to be 42.43 mg/g.

Research on Crosslinking of Polylactide Using Low Concentration of Dicumyl Peroxide

The effects of dicumyl peroxide (DCP) at low concentrations on initiating cross-linking of polylactide (PLA) by melt blending were investigated. Processing characteristics, morphology, thermal behavior and rheology character of PLA gel were characterized by torque rheometer, XRD, DSC and rotary rheometer. The results showed that the crosslink rate of the blends increased with dicumyl peroxide content increasing. The PLA gel with 0.73 wt% of DCP appeared obvious crystallization behavior and a new crystalline structure maybe formed as DCP was 1.4 wt%. And it was also found that the exothermal peak temperature of PLA gel decreased with increasing dicumyl peroxide content except for the gel with 1.4 wt% of dicumyl peroxide. It also has been inferred by rheology analysis that the blend may be the structure of gel or 3D network, and the melt strength was improved.

Synthesis and Thermal Properties of Etherified Konjac Glucomannan

A novel etherified KGM (EKGM) was synthesized with Konjac glucomannan (KGM) and 1-bromopropane in Lithium chloride/dimethyl sulfoxide (LiCl/DMSO). The EKGM was characterized by FT-IR, DSC and TG. The IR of EKGM showed that –OH stretching vibration band decreased and the C–H and C–O–C stretching vibration bands increased comparing with the unmodified KGM, which was indicating that KGM had been etherified. The DSC thermograms showed that an obvious glass transition of EKGM appeared and its glass transition temperature (Tg) decreased with the increasing of Pr/OH ratio. And it was also found that the EKGM had a higher decomposition temperature than unmodified. Meanwhile, it was proved that the EKGM was a good hydrophobic polymer and dissolved in some organic solvent easily.

Lignin-Quaternary Adsorbent: Synthesis, Characterization and Application for 2, 4, 6-Trinitrotoluene (TNT) Adsorption

A lignin-quaternary adsorbent was made from lignin after phenolization and then amination. As-prepared adsorbent was characterized by SEM, IR and DMA. Effects of adsorbent dose, initial pH and concentration on 2, 4, 6-Trinitrotoluene (TNT) removals from aqueous solution by adsorption of this adsorbent were comprehensively investigated. IR spectra showed that the product comprises quaternary ammonium groups in the form of ether bond. The mechanical strength of the adsorbent is enhanced by combining of PVA. It was possible to remove 66% of TNT from aqueous solution with 0.1 g of the adsorbent under certain conditions (100 mg/L and 25 °C). The results indicated that the amount of TNT adsorbed onto the adsorbent increased with increasing initial concentration; however, it decreased with an increase in pH. The adsorption process was determined to be consistent with the Langmuir isotherm.

Adsorption of Strontium from Aqueous Solution Using Collagen Fiber Immobilized Tannins

The removal of strontium from aqueous solution with collagen fiber immobilized tannins was studied. The effects of several experimental parameters such as pH, dosage, temperature, contact time and initial concentration of strontium on removal efficiency of strontium were investigated to determine the optimum conditions of strontium sorption process. The adsorbent was characterized by SEM and FTIR analysis. The results of regression analysis indicated that temperature parameters were not individually statistically significant for Sr2+ adsorption. However, the efficiency of strontium adsorption increased with the increase in pH and dosage. The adsorption capacity was increased with increasing initial concentration of Sr2+. The removal efficiency of Sr2+ was 49% at optimum pH of 6 and initial concentration of 20mg/L. Moreover, the absorption data were fitted well to the Langmuir sorption isotherm model.

Study of Konjac Glucomannan Esterification with Dicarboxylic Anhydride and Effect of Degree of Esterification on Water Absorbency

Dicarboxylic anhydride esterified Konjac glucomannan (DCKGM) was prepared to reduce the unusual water absorbency of native Konjac Glucomannan (KGM). The dependence of degree of substitution (DS) on the reaction conditions and influence of the DS on water absorbency were studied. The esterification was conducted using refluxing KGM in hot acetic acid which contains phthalic anhydride and pyridine catalyst. The chemical structure and characteristic of DCKGM were analyzed by GPC-MALLS and FI-IR. The results showed that the water absorbency for DCKGM is inversely proportional to DS increase. DCKGM may be a promising biomaterial in application of drug carrier, heavy metal ion adsorption and functional packing materials.

Adsorption Studies of Nitrobenzene onto Aminated Lignin

Adsorption performance of aminated lignin (AmL) for nitrobenzene (NB) removal was investigated through batch experiments. The results showed that AmL possessed strong adsorption ability for NB with hydrogen bond interaction. The equilibrium adsorption data were well represented by the Freundlich isotherm model and the saturated adsorption capacity could reach 24.2mg/g. The adsorption process was found to follow pseudo-second-order kinetics. The maximum adsorption of NB on AmL occurred around the neutral pH.

Preparation and Characterization of Thermoplastic Soy Protein Isolate

A soybean protein isolate (SPI) main chain grafted with methyl acrylate (MA) and methyl methacrylate (MMA) as a new thermoplastic copolymer (T-SPI) was prepared. The properties of the material were evaluated with DSC, FT-IR, and rotary rheometry. The results indicated that the monomer was grafted on SPI successfully. The T-SPI had a glass transition at about 66°C. T-SPI was a typical viscoelastic material, and its elastic ratio was 65.27%, the shear viscosity was very sensitive to temperature and the flowability of T-SPI was regulated by temperature.