Advanced Materials Research Vols. 239-242

Abstract: Transparent poly(methyl methacrylate) (PMMA)/TiO₂ nanocomposites have been prepared by solution mixing PMMA with organically soluble titania xerogel. The organically soluble titania xerogel in the form of amorphous phase has been synthesized via a simple sol-gel method, involving hydrolysis of tetrabutyl titanate (TBT) in trifluoroacetic acid (TFA) and gelation. The obtained PMMA/TiO₂ nanocomposites were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM), thermogravimetry (TG) and ultraviolet-visible (UV-vis) absorption spectroscopy. The results showed that the interaction between titania nanoparticles and PMMA macromolecular chains led to a homogeneous dispersion of TiO₂ in PMMA matrix. The resulting PMMA/TiO₂ nanocomposites showed improved thermal stability, high transparency and high UV-shielding efficiency with a small amount of titania xerogel (£3.0 wt%). The present work is of interest for developing a series of transparent UV-shielding nanocomposites.

Abstract: Combining the characteristics of silver inserts, it was tested that its molding process and impact strength from the PA1010 injection molding product's craft. A kind of effective method was found that make sure silver embedded parts not occur surface color as injection heat and determined the reasonable injection molding craft. Meanwhile measuring impact strength of the nylon 1010 injection molding products through the impact test, It was discovered that injection products could well meet the assembly convenient, reliable and the electric conduction needs after inserting the embedded parts in the PA1010 injection molding products. Against molding defects of PA1010 injection molding products and influencing factors of the impact strength, the corresponding analysis was made.

Abstract: A new compatibilizer with polypropylene as matrix, Glyceryl monostearate (GMS) and styrene(St) as functional group was prepared, and its effect on the properties of polypropylene(PP)/montmorillonite(MMT) nanocomposites was investigated. Fourier transform infrared spectroscopy results showed that the GMS and St monomers had successfully been grafted on the backbone of PP. The characterization results of X-ray diffraction(XRD) pointed out the crystallite size perpendicular to the crystal plane in PP/ compatibilizer / MMT nanocomposites was smaller than that of PP. Through detecting of transmission electron microscope(TEM), it can be found that the new compatibilizer will improve the dispersibility of MMT in PP matrix. At last, the mechanic properties of PP/MMT nanocomposite materials get determination, the mechanical strength especially impact strength had a obvious progress when O-MMT was added, and its maximal value impact strength appears in the 3% montmorillonite and 20% compatibilizer.

Abstract: The emulsion combining sol-gel method was used to prepare spherical bioactive glass in the present work. This method involves a two-stage synthesis process: the pre-hydrolysis of tetraethyl orthosilicate (TEOS) in an aqueous acidic solution using templates, and afterward the fabrication of silica spheres by pH induced rapid gelation in a W/O emulsion. Through controlling the two stages separately, the particle size and morphology of silica spheres can be adjusted. These results indicated that emulsion method could supply a good way to prepare glass microspheres.

Abstract: Poly (ethylene-1-octene) (POE) was functionalized to varying degrees with glycidyl methacrylate (GMA) by melt grafting processes. Fourier transform infrared spectra (FT-IR) and 1H NMR spectra confirmed that glycidyl methacrylate was successfully grafted onto the POE. When dicumyl peroxide(DCP)concentration was around 4‰ high graft degree was obtained. The data from GPC measure demonstrates that POE chains degraded during grafting process.

Abstract: Manganese silicate, a stable and efficient catalyst prepared in the laboratory has been successfully used as a catalyst combined with ozonation in the degradation of m-Chloronitrobenzene (mCNB). The catalytic ozonation removal effectiveness of mCNB was investigated under various physicochemical conditions. Both the adsorption and the single ozonation were not effective for the degradation of mCNB, but the presence of manganese silicate in ozonation process could substantially enhance the mCNB removal efficiency. The hydroxyl radical scavenger experiment confirmed that manganese silicate catalytic ozonation followed a radical - type mechanism. The increasing of the manganese silicate dosage could enhance the removal effectiveness of mCNB. The manganese silicate catalyst could be recycled easily without decreasing any ozone catalytic activity after four successive reuses. It is concluded that the manganese silicate was an efficient green catalyst for mCNB degradation in drinking water.

Abstract: Erosion tests on high strengh refractory castables were carried out using SiC grains at impact angles of 30°,45°,60°,and 90° with the velocity of 5m/s.In order to study the variation in stress and system energy with impact angles during solid particle erosion process,a single particle erosion model was designed by means of three-dimensional explicit dynamic software ANSYS/LS-DYNA according to experiment parameters. The Johnson-Holmquist brittle ceramic model was employed to model the failure of target material. The impact angles varied from 15° to 90° in increments of 15°.The simulation results were compared with erosion rate values from experiments. The results show that the variation trends of both the maximum stress of targets and system total energy loss are in a good agreement with experiment data,which increaes with increasing impact angle. The variation of erosion rate as a function of impact angle can be explained by the variation of the maximum stress of target material. The rule “the maximum erosion of typical brittle material occurs at 90°” is confirmed by the view of energy analysis.

Abstract: For getting higher quality product and reducing cost, the article studies the CAE technology used in dies’ design, CAE will help to determine the flattened workpiece size, through workpiece igs file input, grids devided, concrete parameters set, workblank and drawing ribs created, drawing ribs load set, the workpiece produced process will be simulated, the final frame can be watched.while all are well designed, the qualified dies can be obtained.

Abstract: A visible-light-active C-doped TiO₂ photocatalyst was prepared by a simple wet process. The XPS analysis results showed that carbon was doped into TiO₂ particles and one kind of carbonate species with Ti-O-C structure was formed. The obtained sample showed obvious absorption in the 400-800 nm range in UV-vis spectra. By degrading of methyl orange (MO) solution under visible light irradiation (l>420 nm), the apparent rate constant (k_app) of S170 was about 10 times larger than that of P25. The preparation procedure of such C-doped catalyst can be easily scaled up for industrial production due to its simplicity.

Abstract: In this paper, maleopimaric acid anhydride (MPA) has been synthesized by the Diels-Alder addition reaction between abietic acid and maleic anhydride. Single crystal X-ray diffraction analysis reveals that MPA crystallizes in the polar space group P2₁ and contains one MPA and one DMF (Dimethylformamide) molecule in the asymmetric unit. MPA is firstly found to be a new type of low-molecular-mass organic ferroelectric with the saturation spontaneous polarization (P_s) about 60.0-61.6 μC·cm^-2 for single crystal samples, which is close to that of typical inorganic ferroelectric materials. MPA·DMF also shows second-order NLO property, with the second harmonic generation (SHG) responses approximately 0.5 times that of urea.