Advanced Materials Research Vols. 834-836

Abstract: A series of thin, low-cost and environment-friendly organic hybrid composites consisting of reclaimed rubber (R-Rubber) which is a waste product of roller processing of textile mill filled with organic hindered phenol compound 2, 2-methylenebis (6-tert-butyl-4-methyl-phenol) (AO2246) were fabricated. In this study the damping property of the R-Rubber composites were tested in the dynamic mechanical analysis (DMA). The study concluded that R-Rubber/AO2246 composites exhibited an exceptional damping performance with a broad temperature range. Meanwhile, by addition of AO2246, the tan δ peak maximum (tan δ _max) of R-Rubber/AO2246 composite was remarkably increased up to 1.5. Furthermore, with increasing the AO2246 content, storage modulus (E') and loss modulus (E") increases up to R-Rubber/AO2246 (100/80) and then becomes smaller. There is critical value on E and E" increasing which is caused by the excessive crystallization. The Interaction of AO2246 crystallizing, hybridized state and Molecular hydrogen bond led not only to control Tan δ _max of R-Rubber, but also to regulate glass transition temperature and improve the storage modulus, which make R-Rubber have potential applications in fields of engineering.

Abstract: To improve the added value of lignin, the modified alkali lignin of wheat straw was used to prepare waterborne UV-curable polyurethane. The purpose of this paper is to discuss the properties of the cured films made from the above lignin-based polyurethane. The mechanical and optical properties of the cured films were investigated. Results showed that the tensile storage modulus, tensile loss modulus, and tensile loss factor of the cured film were influenced by the addition of the lignin, which indicated that proper dosage of the lignin could change the micro-phase separation structure and improve the mechanical properties of the product. The addition of the lignin also influenced the gloss and light transmittance of the cured film. On the whole, the lignin-based polyurethane exhibits good mechanical and optical performance if proper proportion of the lignin was added to the product. The study was beneficial for utilizing the lignin in high value products.

Abstract: In order to improve the properties of a co-extruded wood-plastic composite (WPC), different types of cellulosic fibres, pulp cellulose (PC), a combination of PC/microfibrillated cellulose (MFC) and wood flour (WF) with different size were introduced into shell layer based on a polypropylene (PP) matrix. The combination of PC/MFC improved the tensile properties compared to PC alone; but the impact strength was independent on the MFCs content. The presence of MFCs did not influence the water absorption (WA), but thickness swelling (TS) increased, however. The properties of the WF/PP-shell composite were highly affected by the WF particle size. The 20-mesh-sized WF-loaded composite had weaker mechanical properties compared to the smaller sized, Arbocel C320, shell-layer filled WPC. Also, Arbocel C320/PP-coated WPC had the highest tensile properties among all studied composites. The morphology of the composites was examined with a scan electron microscope.

Abstract: Porous titanium scaffolds with high porosity are fabricated by sintering. The bioactivity of the porous titanium has been improved by high concentration alkaline treatment. Through the modification, the titanium surface showed a network structures. The SBF immersion test indicates that apatite was formed on the porous titanium scaffold with high porosity after 10M/L alkali treatment in 12h. The results of study show the network structured endowed the porous titanium with bioactivity.

Abstract: In order to understand the effect of β-diketone ligands containing carbazole group on luminescent europium (III) complexes, a series of europium (III) complexes (Phen)Eu (DBM)_3-nL_n with 1-(9-Ethyl-9H-carbazol-3-yl)-4,4,4-trifluorobutane-1,3-dione (L) were synthesized and investigated contrastively (n = 0, 1, 2, 3; DBM: dibenzoylmethane; Phen: 1,10-phenanthroline). The results show amorphous nature, glass transition temperatures and luminescent intensity can be improved obviously by 1-(9-ethyl-9H-carbazol-3-yl)-4,4,4-trifluorobutane-1,3-dione, at the same time, their thermal decomposition temperatures have seldom effected by it. The results verify the performance of europium (III) complexes used as luminescent materials can be effectively improved by the β-diketone ligands of this type.

Abstract: Thick GaN films grown with different V/III ratio on sapphire by hydride vapour phase epitaxy have been investigated. The V/III ratio is changed from 240 to 30. All the GaN films, which are n type, show only (0002) oriented peak and have the band emission with no yellow luminescence bands. When V/III ratio is 30, the full width at half maximum of (0002) X-ray rocking curve is the smallest, line-width of the band edge emission is narrow, the surface morphology shows step-flow growth and the growth rate is the highest.

Abstract: The fundamental performance as abrasive resistance, mechanical performance, heat resistance, process technology of carbon fiber reinforced poly (ether ether ketone) composites, and the application of space and automotive industry was discussed in detail. The development trend of PEEK was forecasted.

Abstract: Recently, using biological ceramsite to treat wastewater has received wide attention. In this study, use of fly ash, cement, calcium oxide, gypsum, expanded perlite as main components, magnetic powder and sodium bicarbonate as complex additive and sodium silicate solution as binder, a novel biological ceramsite was developed by steam curing method. Density, piled density, apparent density and void fraction of the biological ceramsite were tested. The optimal percentage of main components was obtained through the orthogonal experiments. In addition, the main affecting factors were also analyzed on the properties of the biological ceramsite. The results showed that the optimal percentage of magnetic powder, sodium bicarbonate, cement and expanded perlite was 10%, 10%, 10% and 5% respectively.The analysis of the results disclosed that the affecting factors of the density, the piled density, the apparent density and the void fraction were the expanded perlite, magnetic powder, cement (and magnetic powder), sodium bicarbonate, respectively.

Abstract: In this paper, an attempt is made to introduce the defect types relevant to ultrasonic non-destructive testing, and then, we explain how these defects generate in fiber-reinforced composites. The common failure modes which occur are described and discussed. The significance of each of the fracture mechanisms, in terms of their effects on the residual load-bearing properties, is considered. The second part describes briefly the main relevant ultrasonic NDT methods used to identify these defects and indicates the sensitivity to the different types of defect.

Abstract: In this work, hydroxyapatite (HAp) was produced from crocodile bones by thermal process at 900°C. X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR) and Scanning electron microscope (SEM) were used to characterize the obtained HAp. Polylactic acid (PLA)/HAp composites were prepared by melt blending as follows: 95/5, 90/10 and 85/15 (weight ratio). The effect of the amount of HAp on the mechanical properties including tensile strength, modulus, elongation at break and impact strength of PLA/HAp composites was undertaken. It was found that tensile strength and elongation at break of the composites decreased with an increase of HAp content, while modulus and impact strength showed no significant effect.