Abstract: With the rapid development of modern technology and industry, new high-damping materials with comprehensive performance were expected to be invented. Initially, the stress relaxing performance of CIIR/HBP-OMMT composites was investigated. Then, the solvent resistance, crosslinking density, and anti-aging properties of these composites were tested and analyzed. Results demonstrated that this organoclay may improve the damping together with other physical properties of these composites.
Abstract: With the development of science and technology, the design and property analysis of flame retardant materials has become a hot topic. Firstly, TPOSS and DPTPOSS materials were synthesized. Then the different content of RTV/TPOSS and RTV/DPTPOSS were carried out in the horizontal combustion experiment, vertical combustion experiment and oxygen index test, and the experimental data of the two materials were compared.The results shows that DPTPOSS modified RTV has better flame-retardant effect.
Abstract: The combination of different carbon-based fillers (commercial plate graphite (GR) and rod carbon fiber (CF)) were added as conductive fillers to improve the thermal conductivity of polypropylene (PP). The effect of different ratio of carbon-based fillers on the thermal and mechanical properties of GR/CF/PP composites was investigated in detail. A remarkable synergistic effect between GR and CF in improving thermal conductivity of PP composites has been achieved. The results show that the in-plane thermal conductivity rises to 2.8 W·(m·k)-1 at a GR/CF ratio of 5:1 (the total mass fraction of carbon-based fillers to 40wt%), which is 14 times as the thermal conductivity of pure PP (0.2 W·(m·k)-1) and also much higher than that of single filler composites.
Abstract: In this work, experiments were conducted to examine the impact of fiber orientation of self-reinforced polypropylene on wrinkling phenomenon. Defects due to wrinkling are major quality issues in rapid forming of sheet materials. This article examines the influence of two fiber orientations [0°/90° and 45°/-45°] on wrinkling initiation of a self-reinforced polypropylene composite (Curv®) material system. It was found that 45°/-45° specimen wrinkles at smaller axial displacement compared to 0°/90° specimen. In both specimens, there was an abrupt change in strain increment ratio that corresponded to the onset of wrinkling. This phenomenon validates the robustness of the wrinkling indictor based on strain increment ratio concept.
Abstract: This article examines the prediction of wrinkling initiation in self-reinforced thermoplastic composite materials for potential application in rapid forming of this class of materials. Whilst most of recent researches concentrate on examining metallic wrinkling behavior, this article aims to introduce a wrinkling indicator for composite sheet. The material system involved in the study is a self-reinforced polypropylene woven composite with a fiber orientation of 0°/90° along the warp and weft directions. Square specimens were stretched uniaxially along diagonal direction until the onset of wrinkling. It is observed that when the wrinkling occurs, strain increment ratio exhibits an abrupt change. This fundamental observation leads to the prediction of onset of wrinkling by using abrupt changes in strain increment ratio as a metric.
Abstract: The new carbon fiber composite materials trains hood is designed with vacuum infusion molding process characteristics and performance of existing trains hood according to the characteristics of the high specific strength and stiffness of the carbon fiber composite materials. According to the requirements of referring to the IEC61373-1999[Railway Rolling Stock Equipment Shock and Vibration Testing Standards] and GB/T3317-2006[Electric Locomotive General Technical Conditions], the strength and deformation of the trains hood is calculated and analyzed on the conditions of the impaction, air movement load case and the end compression. The test result shows that the mechanical properties of the structure meets the requirements in the 500km/h high-speed test train.
Abstract: This study prepares the HA/PEEK gradient composites with special structural design by impregnation method, which eases the contradiction of the HA/PEEK composites between the lack of bioactivity due to low HA contents and the poor mechanical properties due to high HA contents, and effectively improves the bioactivity and mechanical properties of the PEEK-based materials, and then evaluates the biosecurity of HA/PEEK gradient composites. The main functional cell of bone formation—osteoblast is adopted for the co-culture with PEEK, HA/PEEK gradient composites and the leach liquor, and the effects of PEEK and HA/PEEK gradient composites on the proliferative functions of osteoblast are studied by in vitro cytotoxicity test. The results show that no harmful admixtures are produced in the process of injection moulding, and the leach liquors of PEEK and HA/PEEK gradient composites have no effects on the proliferative functions of osteoblast, with good osteoblast compatibility.
Abstract: In this research solid-solid microencapsulated phase change material (SSMePCM) with high thermal energy storage density (177.6 Jg/1) was synthesized successfully by in situ polymerization using biodegradable natural polymer chitosan as shell and polyethylene glycol (PEG-1000) as core. The morphology, chemical structure and thermal properties were characterized by optical microscopy (OM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The results show that the obtained SSMePCM dispersed individually with a spherical shape. Author (s) recommends the all set thermal and chemically steady microcapsule for thermal energy storage purposes as novel synthesized SSMePCM with latent heat storage capacities.
Abstract: The microwave absorbing rubber was prepared by adding the microwave absorber PPy/Ni/NanoG and other additives into NBR rubber. By analysis, the proper contents of N330, DOP and PPy/Ni/NanoG are 60, 10 and 25, respectively. The reflection loss of the rubber is below-10 dB at 8.2~11.4 GHz and the minimum loss value is-14.58 dB at 9.76 GHz.