Advanced Materials Research Vols. 152-153

Abstract: Soy protein based biodegradable polyurethane (PU) foams were prepared by incorporating soy protein isolate (SPI) into flexible PU foam. The effects SPI content and isocyanate index on the density, resilience, compression set, and biodegradability of the soy protein based PU foams were investigated. The results showed that, soy protein enhanced the compression set, resilience, and biodegradability of PU foams, but increased the density. Furthermore, soy protein can increase open cell proportion in the soy protein based flexible PU foams, and then regulate their properties. The density and compression set value of the soy protein based PU foams decreased with increase in isocyanate index, while the resilience increased. The biodegradability of soy protein based flexible PU foam makes it a prospective material for disposable usage.

Abstract: Effects of ultrasonic on properties of modified soybean protein adhesives for duplex paper were investigated in this paper. The results showed that the treatment temperature had the greatest impact on adhesion strength among all factors. Optimum conditions were obtained by orthogonal experiment as follows: modified temperature 60°C, concentration of urea 5 mol/L , content of protein 14% , reaction time 3 h and ultrasonic time 20min. At the optimized conditions, the adhesion strength of soybean proteins was 0.79MPa.

Abstract: On the basis of experimental study on 5 standard slabs’ vertical bearing capacity, the paper makes an in-depth analysis on the ratio of axial compression stress to strength, the ratio of height to thickness and the influence of embedded block on the axial bearing capacity of the slabs. By establishing finite element model of the slab, the paper analysis the influence factors by means of numerical simulation and establishing the theoretical calculation formula of the slab. Compared with the experimental results, it is showed that the accuracy of the theoretical calculation formula can meet the practical requirements, which provides theoretical calculation basis for engineering practice.

Abstract: The knowledge from extensive investigations showed that the non-linearity of the load and loading point displacement curve is mainly associated with crack propagation. Based on the linear asymptotic superposition assumption, the critical effective crack length is evaluated by analyzing the nonlinear characteristics of the load and loading point displacement curves of a series of the fracture tests. Furthermore, the unstable fracture toughness is determined by inserting the peak load and the critical effective crack length into a formula developed from LEFM. Based on the calculated results, the series K criterion of unstable fracture of concrete fracture is established. At last, an engineering example of cracking analysis of the upstream lock-head foundation of the ship-lift of the Three Gorges Project is given.

Abstract: With structural reliability assessment as the scenario, a structural part made of foam material was treated as a series k-out-of-n system. The strength random variable of a large-size part was characterized by the strength random variables of virtual elements with certain size, as well as the number of the elements determined by part size. Specially, the statistical dependence among element failures was expounded with respect to the virtual elements. A series k-out-of-n system failure probability model was presented, and the failure probability of a structural part of foam material was described in terms of the size parameters of the part in two dimensions: the number of elements in width direction and that in length direction. It was shown that strong dependence among element failures exists, the failure probability of a large-size part will approaches to an upper bound with the increase in part length.

Abstract: Doped water-dispersible polyaniline (PANI) emulsion were synthesized by emulsion polymerization in aqueous medium and characterized by dc conductivity and Transmission electron microscope (TEM). The results showed the PANI has bar-like shape and the diameter is about 200nm. The composite anticorrosion coatings of PANI emulsion and waterborne epoxy resin emulsion (EP) were prepared by mixture in aqueous medium and used for corrosion protection of mild steel. Open circuit potential (OCP) and Electrochemical impedance spectroscopy (EIS) demonstrated that the PANI/EP composite coatings have better anticorrosion properties than EP. It’s impedance and corrosion potential is higher. Scanning electron microscope (SEM) and Energy dispersive spectrometer (EDS) showed that the oxidation film formed on the metal surface and prevent corrosion effectively. The anticorrosion coatings are environmental friendly because of water dispersion medium.

Abstract: The hyper-branched polymer with terminal carboxyl (HPAE-C) was prepared by modifying hyper-branched polymer with terminal hydroxyl with maleic anhydride. The molecular structure of HPAE-C was characterized by IR, 1H-NMR and 13C-NMR. The HPAE-C was used in the finishing process of microfiber synthetic leather, and its effect on the health properties of microfiber synthetic leather was studied. The results showed that hyper-branched polymer could improve the moisture absorption and permeability to water vapor of microfiber synthetic leather. When the dosage of HPAE-C was 8%, the permeability to water vapor and moisture absorption of microfiber synthetic leather were improved by 7% and 13%, respectively. The observation results obtained by using scanning electron microscope showed that HPAE-C could loose the fibers of synthetic leather.

Abstract: The solid-state Ag / AgCl electrode was used to explore the ocean electric field. The effects of sintering technologies on the stability of electrode potential were researched. Four kinds of electrodes, which were respectively sintered to two temperatures of 380°C and 420°C by two heating methods of direct heating and phase-type heating methods, were prepared. Their surface morphologies, metallographic structures and the electrode potentials in 3.5% sodium chloride solution were analyzed to compare the stability of different sintering technologies. The results show that the electrodes sintered to 380°C by phase-type heating - insulation method have the best stability of potential, and potential difference of two electrodes is less than 0.02079mv/h.

Abstract: The effect of load on linear reciprocating sliding friction and wear behavior in a Zr55Cu30Ni5Al10 bulk metallic glass was investigated. With increasing load, the average friction coefficient descends, while the grinding trace width increases. The grinding traces exhibit smooth linear furrows. The larger the load is, the more serious the wear extent exhibits. Under smaller loads, the wear mechanism inclines to a combined result of slight bite or bite welding and continuous wear. While with the increase of load, the wear mechanism changes gradually to the combined effects of continuous wear, occlusion or bite welding, adhesive wear and abrasive wear.

Abstract: This paper was investigated the transient heat transfer characteristics in exhaust port for hydrogen fueled port injection internal combustion engine (H2ICE). One dimensional gas dynamics was described the flow and heat transfer in the components of the engine model. The engine model is simulated with variable engine speed and air fuel ratio (AFR). Engine speed varied from 2000 rpm to 5000 rpm with increment equal to 1000 rpm and AFR was varies from stoichiometric to lean limit. The effects of AFR and engine speed on heat transfer characteristics for the exhaust port are also investigated. The baseline engine model is verified with previous published results. The obtained results clarify that transient heat transfer process inside exhaust port for port injection H2ICE were affected by the engine speed and AFR. It can be seen that for obtained results clarify that for transient analysis, the fluctuation with very small amplitudes for heat transfer coefficient and heat transfer rate during the compression, intake and part of power stroke. The rapid change for both of them occurs during the exhaust and part of power stroke due to the exhaust valve is open. The obtained results from the simulation can be employed to examine the emission production and engine performance.