Advanced Materials Research Vol. 1094

Abstract: In this paper, solid state shear milling method was successfully employed to prepare polypropylene/wood flour composites (WPC) and their structure and performances were investigated. The experimental results showed through solid state shear milling, the aggregates of wood fiber were broken down and polymer closely adhered to wood fiber, which improved the dispersion of wood fiber and the interfacial interaction between PP and wood fiber. As a result, the performances of WPCs in this way were more excellent than that of WPCs by the conventional method. This study could provide a novel approach to resolve the problems of the dispersion, stabilization and compositing of wood flour with polymer matrix and prepare WPC with higher performances.

Abstract: The slow crystallization speed of poly(Lactic acid)(PLA) has limited its application. In this work, the surface of Talc was grafted with oligo PLA, and then modifed Talc /PLA was prepared, and the results showed that the modified HA could greatly enhanced the crystallization of PLA.

Abstract: The wood flour/HDPE microcellular foamed composites were prepared by means of torque rheometer. The effect of different wood flour content on mechanical properties and foamed behavior were studied. Results showed that the tensile strength and flexural strength of microcellular foamed composites first increased then decreased and the notched impact strength decreased with addition of wood flour, this was consistent with non-foamed composites. The density of composites increased and the density of foamed composites was less than non-foamed composites. With increasing wood flour content, the cell diameter of foamed composites first decreased then increased. When the content of wood flour was 40%, the cell diameter of the composites obtained the minimal value.

Abstract: A wet-rubbing fastness improver was prepared by two steps: (1) synthesis of waterborne polyurethane (WPU) through the reaction of diphenylmethane diisocyanate (MDI), polyethylene glycol (PEG), dimethylol propionic acid (DMPA), and diethylenetriamine; (2) modification of WPU by reaction with epichlorohydrin. Influence of temperature, time, concentration and ratio of monomers on the preparation was studied. The optimal process for WPU synthesis is as follows: temperature 100°C, time 3h, diethylenetriamine 1.5 % and DMPA7% (on weight of monomers). The modification reaction can be proceeded at temperature 100°C for 2h with epichlorohydrin 2.7 %.

Abstract: Calcium carbonate whisker is a new kind of environmental-friendly inorganic material. Some advantages of calcium carbonate whisker such as low manufacture cost, simple preparation condition and excellent properties draw a lot of attention and make it higher potential competitive in the market. This review summarizes the research progress of calcium carbonate whiskers prepared with the different methods such as carbonation method, metathesis reaction method, sol-gel method, urea hydrolysis method and gravity crystallization method, and describes the research status in diverse applications of calcium carbonate whisker in enforcement of composite materials, being as filler of paper-making and additives in friction materials.

Abstract: The Pd/C catalyst with high dispersion was prepared by the activated carbon loading palladium nanoparticles (Pd-NPs) obtained in the protection of Tween-60. The above-prepared Pd/C catalyst was characterized by X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometry (ICP-AES), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), chemical adsorption instrument. The influences of the size, dispersion, crystal type and electronic state of the Pd/C catalyst on catalytic activity were investigated. The results of Suzuki coupling reaction over the above-prepared Pd/C demonstrated that the reaction yield of aryl bromide under the conditions of 60°C for 1 h and para-chloronitrobenzene under the conditions of 80°C for 12 h reach 99% and 73% respectively.

Abstract: MgAl-CO₃^2--LDH was exfoliated via two-step ultrasonic treatment in formamide. Atomic force microscopy (AFM) was employed to characterize the thickness variation of MgAl-CO₃^2--LDH during exfoliation. MgAl-CO₃^2--LDH was dispersed in formamide with continuous ultrasonic treatment for 4 h, getting a non-transparent turbid liquid. The non-transparent turbid liquid was laid aside one day and separated into two phases, the upper semi-translucent colloidal suspension containing partial exfoliated MgAl-CO₃^2--LDH was dispersed in formamide with continuous ultrasonic treatment again. The AFM results reveal that the thickness of pristine MgAl-CO₃^2--LDH is 250 nm while the MgAl-CO₃^2--LDH nanosheet obtained from the first-step ultrasonic treatment is 90 nm with obvious transverse sliding. The thickness of MgAl-CO₃^2--LDH nanosheet obtained after the second-step ultrasonic treatment is about 7 nm, which is almost in agreement with the theoretical thickness of 10 monolayers of MgAl-CO₃^2--LDH (0.76 nm).

Abstract: Three kinds of colloidal silica (GS-30, AM and HS-30) were applied as binders to corundum-mullite castables. The apparent porosity and cold modulus of rupture for samples fired at 800 oC and 1000 oC were compared. The fractography of colloidal silica bonded corundum-mullite castables was carried out by slit island method. The microstructure of fracture surface was characterized by scanning electron microscope. The results showed that castables by using imported colloidal silica (AM and HS-30) presented higher strength than those with domestic (GS-30), which was determined by the activity of silica and modified ion. The difference of the size distribution of the salient on the fracture surfaces indicated that the strength of castables was dependent on the bonding among the components.

Abstract: The Hesigewula lignite was studied by heat treatment in a fixed bed and moisture absorption experiment. The temperature of heat treatment was considered as a factor to investigate its influence on product yield. Under the gas carrier (N₂) flow rate of 200 SCCM, 0.5 MPa and holding for 20 min, the yield of tar firstly increased and reached the maximum of 5.67 wt% at 500 °C, then came to a decrease with the increasing temperature. The proximate and ultimate analyses of the solid products had been measured. As to the moisture adsorption experiment, the equilibrium moisture content of the solid products at different humidity (30 °C) had been calculated. It was shown that the char of 600 °C adsorbed the least moisture with the minimum content of oxygen. It indicated that heat treatment can remove the oxygen-containing functional group and to some extent upgraded the coal rank.

Abstract: Abstract: The Co²⁺ doped TiO₂ film(Co-TiO₂) was prepared by in-situ growing on the pure Ti plate substrate in the electrolyte solution of Na₃PO₄ containing CoSO₄·7H₂O by micro-arc oxidation (MAO) process. The effect of the amount of CoSO₄·7H₂O adding into the electrolyte solution on structure of Co-TiO₂ and its activity of photo-catalytic hydrogen production had been studied. It was found that the characteristic peak(101) of anatase phase and the characteristic peak(002) of rutile phase appeared and the red shift of absorption edge occurred for Co-TiO₂ films when adding CoSO₄ into the electrolyte solution. It was shown from experimental results that the highest hydrogen production rate was 0.33 μmol/ h·cm² over the above-prepared Co-TiO₂ in CoSO₄·7H₂O content of 8.7 g/L.