Advanced Materials Research Vol. 1090

Abstract: A variety of castor oil-based cationic polyurethane dispersions (PUDs) were synthesized. The effects of hard segment content on the properties of PUDs and the resulting polyurethane films were investigated by mastersizer, Fourier transform infrared (IR), thermal gravimetric analysis (TGA) and stress-strain test. As the hard segment content increased from 37.1 to 45.6 wt %, the particle size of the PUDs increased from 10 to 190 nm. IR analysis showed that hydrogen bonding between hard segments enhanced with the increase of hard segment content. For this enhancement the films had an increased tensile strength from 2.0 to 9.4 MPa and an improved glass transition temperature (T_g) from 48 ^oC to 75 ^oC. TGA showed the films were thermally stable up to 200 ^oC and had biphasic degradation at around 330 ^oC and 440 ^oC. The versatile castor oil-based cationic waterborne polyurethanes are promising in applications as adhesives and coatings.

Abstract: In this paper, based on triethanolamine on application effect of reactive dyes, the design of a new kind of dyeing assistant NN '- three the two amine ether, through the experiment, verify the dyeing assistant and good effect of reactive dyes with good fiber in dyeing process, has practical significance of application of reactive dyes.

Abstract: A novel hybrid/inverse identification method is developed to predict the time-dependent shear interfacial mechanical properties of the adhesive layer. In this method, to effectively predict the mechanical behavior of the shear joints, which was made of the aluminum alloy and silica gel structural adhesive, a novel time-dependent shear interfacial model was embedded in the joints to denote the adhesive layer. Based on the interfacial failure results obtained from experiment and the numerical simulation, the hybrid/inverse identifying time-dependent interfacial parameters is constructed by means of genetic algorithms and the time-dependent interfacial adhesive parameters can then be determined. By independent experiment verification, it is found that the hybrid/inverse identification method is promising in identifying time-dependent interfacial parameters of adhesive bonded structures.

Abstract: As high polymer materials, textile materials are easily to be carbonized and then disappear, so it is almost impossible to study the origin of it from physical evidence. Based on the objective historical facts, through analysis and inference, the paper believed that textile materials, as soft materials, are better than stone tools in the aspects of obtaining, making, functions and uses. Two hypotheses about the origin of textile materials are proposed. The first is that textile materials originate from tools, and the origin time of it is not later than stone tools. The second is that signs and clothing application of textile materials both evolve from its usage as tools, so the origin sequence of textile materials is tools, signs, and clothing.

Abstract: This paper aims to discuss the composite materials application in ocean oil and gas flexible pipes, from the functional principles to the technical methodology in materials selection and pipe structure design.

Abstract: The mechanism for the change in the size of the geometry of graphite crystallites in polyacrylonitrile-based carbon fibers heat treated at 1500–2500 °C is proposed. The study indicated that the growth transition temperature of graphite crystallites in carbon fibers is 2000 °C. Above 2000 °C, the interlayer space (d₀₀₂) decreases slowly and an ordered graphitic structure forms. Below 2000 °C, the variation in the size of the crystallites along the directions of the axis (L_a‖) and the radius (L_a⊥) of the carbon fibers that were heat treated at various temperatures was almost the same and the crystallite form factor, L_a‖/L_a⊥, which is nearly 1. Above 2000 °C, L_a‖/L_a⊥ increases rapidly because the anisotropy of the arrangements of the crystallites in the carbon fibers and the geometry of the crystallites change from being square to becoming rectangular. The crystallite thickness (L_c) also increases with an increasing temperature and below 2000 °C the crystallite form factor (L_a‖/L_c) increases rapidly. Above 2000 °C, the L_a‖/L_c stabilized at 3.1. The different growth models in the different directions are the intrinsic root for the variations in the crystallite geometries that underwent high-temperature heat treatments.

Abstract: A series of stable double-terminated UV reactive cationic waterborne polyurethane dispersions was synthesized, while the structure was confirmed by infrared spectroscopy,laser particle size analysis and free NCO root titration; modified by co-monomerhydroxyethyl acrylate with the UV radiation fast curing, the influence of hydroxyethyl acrylate proportion and the polyurethane’s n_NCO/n_OH(R value) to the thermal properties, mechanical properties and yellowing of the product was investigated. The investigation illustrated the UV-curable cationic waterborne polyurethaneacrylate film effectively forming a semi-interpenetrating network system to achieve rapid curing coating.The results showedthe product cured by WPU dispersion of R=1.5 mixed with equimolar HEA obtained lowyellowing, the maximum breaking strength, high elongation at break, high thermal decomposition temperature, high crystallization temperature of hard segment, low glass transition temperature of soft segment, high degree of phase separation, better overall performance.

Abstract: It’s generally accepted that the transport of lithium ions in solid polymer electrolytes exists mainly in the amorphous regions, thus the research has focused on reducing the crystallinity to obtain high conductivity at room temperature. However, the point has been challenged: crystalline systems can provide a better ionic conductivity. In this paper, PEO/LiClO₄ polymer electrolytes with different lithium-oxygen ratios were prepared by melt-blending. The results show that [EO]/ [Li⁺] = 3 system has higher ionic conductivity, 4.26×10^-6 S/cm, more than twice as that of [EO]/ [Li⁺] = 4 system. DSC and XRD results show PEO₃:LiClO₄ crystalline phase present in both systems, the crystallinity of [EO]/ [Li⁺] = 3 system is higher. It illustrates the generally accepted mechanism is not suitable for these systems, suggesting the high conductivity of [EO]/ [Li⁺] = 3 system is due to the unique crystal structure of PEO₃:LiClO₄. Besides, as the crystallinity increases, the tensile strength of [EO]/ [Li⁺] = 3 system increases greatly, to 1.43 MPa. In addition, because of the high melt temperature of PEO₃:LiClO₄, the electrolytes will gain excellent heat resistance. In summary, this paper provides a new idea to prepare polymer electrolytes with high ionic conductivity, improved strength and excellent heat resistance in large scale.

Abstract: The electrocatalytic performance of graphene oxide frameworks (GOFs) for producing hydrogen peroxide is reported. Three different GOFs are synthesized by interlinking the graphene oxide sheets with different boronic acid deviates through the hydrothermal method and their electrochemical performance are investigated via cyclic voltammetry (CV) and rotating disk electrode (RDE) experiments. Through these electrochemical experiments, we find GOFs favor a 2e^- reduction pathway and perform high activity and selectivity in the hydrogen peroxide production process. Taking advantage of these catalysts for the electrochemical synthesis of hydrogen peroxide has the potential to establish a safe, sustainable, and cheap flow-reactor-based production method.