Advanced Materials Research Vols. 887-888

Abstract: In this work, typical polybenzoxazine, as new class of phenolic resin, has been used as a matrix for preparing a series of high performance hybrid materials using various amounts of titanium carbide (TiC) ranging between 0-10 wt% as fillers, via a solution blending technique. The thermal properties of bisphenol A-aniline base benzoxazine monomers (BA-a) and TiC mixtures have been studied by differential scanning calorimetry (DSC). The thermal stability of their cured hybrids has been tested by means of thermogravimetric analysis (TGA). The result showed that the glass transition temperature of the prepared composites increased with increasing the amount of TiC to reach a higher value at 194°C. Also, the incorporation of TiC nanoparticles has considerably improved the thermal stability of the hybrids including the char yield which increase by 50 % at 10 wt% TiC content.

Abstract: Different kinds of compound solutions were prepared by using different concentrations of hydrophobically associating polymers and sulfonate type surfactant. The static viscosity and interfacial tension of these solutions were measured. On the experimental conditions of the Suizhong 36-1 oilfield, the relative permeability curves of the water flooding and the surfactant/polymer combination flooding were measured through the constant speed unsteady method and the experimental data were processed through the way of J.B.N. The several existing kinds of viscosity processing methods of non-newtonian fluid were compared and analysed , and a new way is put forward . The results show that the relative permeability of the flooding phase is very low while displacing the heavy oil; the relative permeability of oil in combination flooding is higher than that in water flooding, the relative permeability of flooding phase in combination flooding is lower than that in water flooding and the residual oil saturation of combination flooding is lower than that of water flooding. Meanwhile, the concentrations of polymer and surfactant have a great influence on the surfactant/polymer combination relative permeability curves.

Abstract: This Paper studies the important role of the Composites, in the complex process of designing Solar Refractive Concentrators, that would be unthinkable and unrealizable without their employment, when having necessary the technical characteristics that they make them viable. It contributes, also, the methodologies followed for the accomplishment of optimal prototypes, by means of Numeric Methods of simulation (Finite Elements), experimental on models and of characterization of composite laminates.

Abstract: The velocity history of free-surface particle for carbon phenolic composites (density is 1.4g/cm³) is obtained based on the loading technology of the light gas gun, the relationship between the striking velocity of flyer and the spall thickness as well as time is investigated. Besides, spall strength and thickness are obtained by analyzing the samples data and curves. The high pressure physical characteristics, such as type Hugoniot curve and Murnagham state equation for this material, are acquired by analyzing the velocity history of free-surface and spall characteristics. This study provides a methodology to quantify spall and physical characteristics for carbon phenolic composites under tensile wave loading.

Abstract: In this paper, low temperature oxygen plasma treatment method was adopted to process the carbon fiber surface and ILSS and Flexural Strength test method were utilized to represent the interfacial shear strength and flexural strength of CF/PES-C composite material. By aid of SEM, this paper observed the interfacial shear and flexural failure morphology of CF/PES-C composite material. Then this paper compared the hygroscopicities and strength retention rates of CF/PES-C composite material before and after the plasma treatment. Results showed that the optimum treatment conditions of carbon fiber were 300W treatment power and 15-minute treatment time. Under this kind of condition, the highest ILSS value of the composite material shall be improved by 24.9% and the highest flexural strength value be increased by 19.55%. After the proper plasma treatment, the interface adhesive property of carbon fiber and PES-C resin matrix can be strengthened, which will further improve the mechanical properties of composite materials.

Abstract: This paper focuses on both thermal and mechanical properties of the composite pastes. Heat-treatment was carried out at temperatures up to 105 and 900 °C for 6h, respectively. Thermal conductivity of the specimens enriched with 3 wt% nanoSiO₂ was approximately 60% higher than that of pure paste. Volume heat capacity of the composite pastes displayed 28% increase. Moreover, the composite pastes contributed to ~25% improvement of compressive strength. XRD, and TG-DSC were employed to investigate the cause of physical and thermal changes in the heated specimens.

Abstract: Carbon fiber reinforced polymer matrix composites have been widely used in many fields. It is necessary to test the performance of interlaminar fracture toughness of composites and provide useful information for product development and material selection. In this paper polymer matrix films embedding with carbon fiber reinforced composite laminates curing at high temperature were used to study the performance of model I inter-laminar fracture toughness. Mode I interlaminar fracture toughness of composites reinforced by carbon fiber was measured according to ASTM D5528 standard. Three groups of samples cut into double cantilever beam (DCB) specimens were measured to compare their performance. The results showed that there was no fiber-bridging in multidirectional composite laminations. The delamination for all specimens extended slowly and stably. All of three groups of carbon fiber composites had strong model I interlaminar fracture toughness and high delamination tolerances. The sensitive to delamination is different because of different composition of these three carbon fiber reinforced composites.

Abstract: In the paper, regarded SiO₂-Al₂O₃-B₂O₃-RO system as basic composition, high-temperature glass glaze was prepared successfully by using Bi₂O₃ in place of Al₂O₃, and traditional melt annealing method was adopted .The influence of Bi₂O₃ on expansion coefficient, sintering temperature, electrical resistivity was investigated by DIL-2008, SJY sintering imager, Keythley2410. The results show that the sintering temperature of glass glaze has a wide range, which can reach 270°C, so it is easy to sinter; with the increasing of bismuth oxide content, expansion coefficient of glass glaze gradually increases, whereas sintering temperature and electrical resistivity continuously decreases.

Abstract: Melamine salt of pentaerythritol phosphate (PPM) was synthesized with phosphoric acid, pentaerythritol and melamine. This flame retardant polypropylene containing cerium oxide (CeO₂) can be used as a synergistic agent for the flame retardancy of intumescent flame retardant polypropylene system. The pendulum impact tester and universal material machine were used to evaluate the mechanical properties of intmescent flame retardant system, the limiting oxygen index (LOI), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were used to evaluate the synergistic effects of CeO₂. The LOI value of the system increased when reasonable amount of CeO₂ was added, and it reached maximum (30%) when the mass fraction of PPM was 20% and CeO₂ added was 1% of the PPM/PP system. The TGA data shows that CeO₂ can enhance the thermal stability of the intumescent flame retardant polypropylene system at high temperature and effectively increase the char residue formation. The morphological structures observed with SEM demonstrate that reasonable amount of CeO₂ can improve the morphologies of intumescent char layer and the properties of heat insulation and barrier material. The reasonable amount of CeO₂ in the system can increase its impact strength and decrease its tensile properties.

Abstract: An acrylate resin copolymerized with epoxy and amino resin was prepared in this paper, and its polyhedral oligomeric silsesquioxane (POSS) modified nanocomposites were fabricated via physical blending. Results showed that glass transition temperature of the acrylate copolymer was about 7.9 oC via DSC. Dispersion of nanocomposites with aminopropyllsobutyl POSS is better than those with Octalsobutyl POSS. Moreover, glass transition temperatures of the nanocomposites with POSS are close to the acrylate copolymer matrix.