Key Engineering Materials Vol. 852

Abstract: Polyurethane - Dispersed Diazo Black GNN Polymer dye (PU-DDB GNN) was synthesized by incorporation of DDB GNN into polyurethane chains. The expected structure of polyurethane-dispersed diazo black GNN polymer dye was confirmed by FT-IR and UV-vis spectra. The photochromic phenomenon of polyurethane-dispersed diazo-black GNN dyes was investigated. And through the thermogravimetric analysis and differential calorimetry analysis, it is confirmed to be an amorphous structure with good thermal stability. Through the test of its mechanical properties, the results show that the elongation at break is quite high.

Abstract: The purpose of this paper is to obtain the best process parameters of polypropylene bottle injection molding. This paper obtained the gating system of polypropylene bottle embryo by using MOLDFLOW according to the structural characteristics of polypropylene bottle embryo, and optimized the process parameters by using taguchi method within the reasonable range of process parameters. In this paper, six parameters about time, pressure and temperature were selected as factors for the mold flow analysis of polypropylene bottle embryo injection molding, and there were four levels in every factor. The volume shrinkage, sink index and residual stress in the first and second directions in the cavity were selected as evaluation indexes. In order to reduce evaluation indexes, the signal to noise ratio of each factor and each level were calculated, and the adjustable factors were adjusted to obtain the minimum evaluation indexes and optimal combination of process parameters. The optimum process parameters such as melt temperature 200°C, molding temperature 20°C, injection pressure 50Mpa, injection time 2.1s,dwell pressure 44Mpa, dwell time 40s were gained.

Abstract: On the one hand, accordingly to remove the surface impurities, we purified the prepared Multi-walled carbon nanotubes (MWCNTs) in our advance experiment; ferrous ions and iron ions in lye through the action of micro-filtration membrane to form smaller size Fe₃O₄ magnetic particles on the other hand. The prepared magnetic Fe₃O₄ with small particle size was loaded on the adorption point of the multi-walled carban nanotubes(MWCNTs) to form magnetic carbon nanocomposites. In order to achieve the best adsorption effect, the preparation temperature was improved in the experiment, and the influence of the ratio of ferrous ions to iron ions on the properties of the material was adjusted. The best adsorption properties of the composites were confirmed by X-ray diffraction and Fourier infrared spectrometer phase analysis. In addition, the application of this experiment to water treatment has a good effect on the copper ion removal.

Abstract: Textile and dyeing wastewater is the major source of environmental water pollution all over the world, which has complex composition so that conventional methods are difficult to remove and degrade. Based on the relevant research, this paper proposes to add further treatment by using macroporous resins on the basic of the conventional treatment and explore the effects of the adsorption and desorption, such as the pH value, initial concentration of , temperature and the flow rate. The performance of six kinds of macroporous resins (DA-2, D280, DA201, D3520, AB-8 and DA-201) for the advanced treatment in the textile and dyeing wastewater has been evaluated. The adsorption and desorption properties of the contaminants, which tested by the six kinds of the macroporous resins in the textile and dyeing, have been compared. According to the results, D3520 resin holds the highest adsorption and desorption capacity. (15.6mg/g for adsorption capacity, 15.1mg/g for desorption capacity). The effects of the pH value, initial concentration of , temperature and the flow rate on removal of by D3520 macroporous resin have been tested. The results showed that the removal of increased with the pH value and initial concentration of COD increasing and the data of its adsorption fitted the Langmuir isotherm best. Besides, 92.49% could be removed after 8h of adsorption at 25 °C. Dynamic adsorption and desorption experiments have been carried out on the packed column of D3520 resins as a reference for engineering applications, the results showed that the D3520 resin could still reach 79.5% removal rate after adsorptions-regeneration for five times.

Abstract: In this paper, the common diseases about bridge deck pavement of the completed highway in Heilongjiang province have been made practical investigation and analyze why these diseases happen. It also combines the climate features in north cold areas，from the way of using High quality modified asphalt，reducing the catalytic point temperature of pitch to improve the low temperature anti-crack property, using high strength coarse and fine aggregate，adjusting gradation of mixture aggregate and the ratio of oil to stone to improve temperature and water stability and durability for Concrete pavement project of Nao Li river bridge connected Jian San river with Hu Lin highway .From trabecular bending test、Freeze-thaw splitting test、Rutting test and Immersion Marshall test，that compares different influence research on pavement performance of bridge with Bitumen concrete bridge deck which have different polyester fiber content .The experimental result indicates the proportion of polyester fiber can clearly ameliorate the temperature stability、hypothermia anti-cracking performance and water stability of Asphalt .And within a certain range of polyester fiber content，various road performances will be improved with the increasing of polyester fiber content，and on this basis，the optimum polyester fiber content is raised.

Abstract: The micro-mechanical properties and micro-structural characteristics of the interfacial transition zones of recycled concrete with graphene oxide were studied by using nanoindentor. The results showed that the average elastic modulus and width of the interfacial transition zone of recycled concrete with graphene oxide between new paste matrix and natural aggregate were about 20GPa and 30-35μm, respectively; The mean elastic modulus and transition zone width of the interfacial transition zone between new paste matrix and old paste matrix was about 35GPa and 25-30μm, respectively. By analyzing and calculating the probability distribution of hydration products, it was found that the graphene oxide template increased the proportion of calcium silicate hydrate in the hydrate and enhanced the content of calcium hydroxide crystal group. Compared with ordinary recycled concrete, the elastic modulus distribution in the interfacial transition zone was more uniform and the microstructure was more stable. It can be concluded that graphene oxide can enhance the mechanical properties and microstructure of the interfacial transition zone of recycled concrete so as to improve the macroscopic mechanical properties of recycled concrete.

Abstract: In order to explore the application of nanomaterials in fiber concrete, in this research, the effect of nanomaterials SiO₂ on the basalt fiber concrete was studied with experimental analysis methods. The variation values of mechanical properties were calculated respectively. On this basis, the influences of silicon dioxide nanometer and basalt fibers on the mechanical properties of nanosilica silicon dioxide nanometer basalt fiber concrete were studied. Different contents of silicon dioxide nanometer were added to concrete, different contents of basalt fibers were added to concrete, and both were added to concrete. The results showed that adding silicon dioxide nanometer could modify building concrete and significantly improve the mechanical properties of concrete. the increase of silicon dioxide nanometer content of nanomaterials, the strength of concrete showed a trend of first rising and then falling. When silicon dioxide nanometer content was 1.2%, the mechanical strength was the largest. As the contents of basalt fiber increase, concrete strength showed a trend of first increasing and then decreasing. When basalt fiber content was 3kg/m³, it was the optimal content and the concrete strength was the largest. And the mechanical properties of the concrete mixed with silicon dioxide nanometer and basalt fibers were significantly improved.

Abstract: In order to study the electrochemical sensor of nanometer mechanism materials to realize the high sensitive detection of different chemical molecules, in this research, the preparation methods of molybdenum dioxide nanomaterials, molybdenum dioxide/metal particles (Au, Pt, Au@Pt) composites and the preparation of molybdenum dioxide nanomaterials, molybdenum dioxide /Au composite nanomaterials, molybdenum dioxide /Pt composite nanomaterials and molybdenum dioxide /Au @Pt composite nanomaterials were introduced. Then the electrochemical behavior of several modified electrodes, electrochemical behavior in catechol system, scanning and pH were applied to the modified electrode. Finally, the electrode p-catechol system was detected by differential pulse voltammetry and the actual samples were analyzed. The results showed that compared with unmodified electrode materials, the electrode modified by molybdenum dioxide nanomaterials, molybdenum dioxide /Au composite nanomaterials, molybdenum dioxide /Pt composite nanomaterials and molybdenum dioxide /Au @Pt composite nanomaterials has better electrocatalytic performance and the detection of catechol has a good effect. Among them, the electrochemical sensor constructed by MoS₂-Au@Pt composite has the best detection performance for catechol. The results have a good guiding significance for the performance improvement of electrochemical sensor.

Abstract: The Polyamide 6 (PA6)/ maleic anhydride grafted ethylene-propylene-diene monomer (EPDM-g-MAH)/organic montmorillonite (OMMT) nanocomposites were successfully prepared by melt extrusion method at different contents of OMMT fillers. The content of OMMT were studied to discuss the mechanical properties, thermal resistance properties and melt-crystal behavior of the nanocomposites. The results were summarized as follows: The PA6/EPDM-g-MAH/OMMT nanocomposites were prepared using melt extrusion method. The influence of the OMMT filler contents on the properties of PA6/EPDM-g-MAH/OMMT nanocomposites were studied. The mechanical properties and thermal resistance properties were improved with the addition of OMMT. The results showed that when the content of OMMT was 3.5wt%, comparing to the pure PA6, the bending strength was improved 31.7%, the notch impact strength was improved by 40.5%, and the heat deflection temperature was improved by 31.1°C. This kind of nanocomposites had good application prospects.

Abstract: By mechanical blending method or melt extrusion method, several kinds of poymers and OMMT were selected with different mixing progress and conditions, and several polymer/OMMT nanocomposites with different substructure morphology were prepared. The properties of polymer/OMMT nanocomposites were investigated. Firstly, several types of OMMT were prepared with different layer spacing, the results of XRD and TEM showed that the OMMT with larger layer spacing would form exfoliation nanocomposites, and then the schemes explained the mechanism. The polyethylene (such as LDPE, HDPE, LLDPE) composited with the same OMMT indicated the influence of different molecular chain structure. Different morphology of PP/OMMT and EPDM/OMMT nano-composites were discussed to find the relationship of shear force effecting structure.