Advanced Materials Research Vols. 550-553

Abstract: Chitosan and acrylamide were used for graft reaction by photoinitiator, and flocculation performance of grafted product was also studied. In addition, the impact of the trigger system, reaction time and temperature on product performance were discussed in detail. Structure property of the product was characterized by infrared spectroscopy. It is found that the highest stem grafting rate of graft copolymer can reach 239.4 % using this process, and the specific viscosity of product can reach 820 ml/g. The flocculation test was done by coal slurry water, and its result shows that the light transmission rate of slime water is up to 98.7 %.

Abstract: The two-way mass transfer behavior between solvent and non-solvent is a key factor effecting on the pore size and size distribution of 3-D scaffolds formed by ScCO₂ induced phase separation process. The mathematical model of the mass transfer related to this process is presented on the basis of the model developed by Reuvers. By means of the composition paths calculated by this model in the ternary phase diagram, the pore size and size distribution of PLLA 3-D scaffolds are analyzed under different conditions (solution concentrations, CO₂ pressures and temperatures).The calculated results are verified by experiment. The results show that the pore size of the PLLA 3-D scaffolds increases with the decrease of solution concentration and increase of the CO₂ pressure and temperature.

Abstract: One kind of polymer with m/z 113 was found from extracts in oil shale using liquid chromatography tandem mass spectrometry (LC-MS). The polymer studied in this report was as follows: a preparation and purification method of extraction was set up, a LC-MS detection measure of the polymer was established and the splitting way of the polymer was verified rationally.

Abstract: In this study, the composites prepared from polyimide (PI) and polyaniline (PANI) were radiated with electron beam (EB) at the radiation doses of 0, 50, 150, 200, and 300 kGy. The electrical conductivity and thermal properties of the radiated composites were determined and compared with those of the composites doped with 6M HCl. The results revealed that the electrical conductivity was enhanced from 3.42 x 10-16 S/cm (untreated polyimide without polyaniline) to 6.97 x 10-5 S/cm when the PI/PANI composite was doped with HCl at 10 phr of PANI; furthermore, the conductivity was increased to 2.16 x 10-4 S/cm for the composite at 10 phr of PANI with radiation dose of 200 kGy. In addition, it was found that the glass transition temperature of the composite was increased with the increase of PANI content for either EB radiation method or protonic acid doping method. It could be noted that the electrical conductivity values of the radiated composites were higher than those of composites doped with HCl at the same PANI content.

Abstract: The synthesis of corn starch acetate made by traditional chemical modification technology of starch in continuous ultrasonic field was investigated in this experiment. This study mainly focuses on the effects of ultrasound wave power, frequency, reaction time and amount of reactants on degree of substitution of starch acetate. The structure of the product was characterized by scanning electronic microscope(SEM), polarizing microscope, X-ray diffraction and infrared spectrum. The results show that the degree of substitution(DS) of the product is influenced by the power and frequency of ultrasound waves, the reaction time and the amount of reactants. The effect of the ultrasonic power is the most significant. The optimal condition was power 250W, frequency 60kHz, reaction time 75min and the amount of esterifying agent 20ml. The degree of substitution of the starch acetate under such conditions was 0.1043. The appearances and crystal structure of the synthetic starch acetate particles changed under the effect of ultrasonic field. There were concavities and cracks on the surface of the particles and the crystal structure were damaged resulting in lower degree of crystallinity. Infrared spectrum analysis showed that although acetyl groups are introduced into the molecules of starch , the basic structure of the starch molecules were not affected by the ultrasound waves.

Abstract: The sodium salt of Poly(acrylic acid-maleic anhydride) was prepared by solution polymerization method and applied to 75% thifensulfuron WDG. The results show that granule suspension rate all achieves 85% above, disintegrating time is less than 60 seconds, thermal decomposition rate is less than 3%.That meet WDG various technical indicators.

Abstract: Aromatic polyimide was synthesized by pyromellitic dianhydride (PMDA) and diamine with aromatic ether. An optimized compression molding process for producing high performance engineering plastics from aromatic polyimide was investigated. The plastics showed high thermal stability, excellent mechanical and electrical properties. The polyimide which was characterized by IR spectra, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) exhibited glass transition temperatures (Tg) at 270 °C, and 5% weight loss temperature at 537 °C. Additionally, a novel technology relating to the recovery of solvent under vacuum condition was proposed, and exhibited better mobility of powder and toughness of plastics, low costs and hydrolysis rate.

Abstract: Lower-melting point polyamide-6 (LPA6) with the melting point of 198°C was prepared through melting extrusion. Blends of poly (Vinyl Chloride) (PVC) and LPA6 which use epoxy (EP) as compatibilizer were prepared by blending PVC and LPA6. The effects of the composition of PA6 and epoxy on the morphology and mechanical properties were investigated by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The behavior of the blends was also determined experimentally using the dynamic mechanical analysis (DMA). Experiments revealed that, the epoxy resin F51 plays a compatibilizer. The more of the content of epoxy resin, the better of compatibility between PVC and PA6. With the increase of PA6, the degree of crystallization, crystallization rate and the regularity of crystal grain increased, the tensile strength declinged, the flexural strength and notched impact strength increase first and then decrease, both of then had an extreme value when the content of PA6 is 20wt%.

Abstract: Low Density Polyethylene (LDPE) foam of open-cell type was manufactured through extrusion foaming system using a physical blowing agent for the application of sound absorption. For the purpose of enhancing the open cell content, salt powder was blended with LDPE changing the content and particle size. Scanning electron microscopy (SEM) analysis was carried out in order to observe the cell morphology. With a view to characterizing the open-cell structure, open-cell content and expansion ratio were measured with extruded foams. Finally the effect of formulation and processing parameters on cell morphology was investigated.

Abstract: Fe3O4 magnetic nanoparticles were as seeds and synthesized by the chemical co-precipitation and modified by bilayer surfactants. Styrene was as monomer in the emulsion polymerization ;And copolymerzation of both monomer with crylic acid and enfold Fe3O4.Use TEM observed: in the same experiment condition the magnetic microspheres of copolymerzation with crylic acid were enfolded better.And effects of adding methods of AA and its concentration on the content of magnetic microspheres surface carboxyl groups were studied.