Advanced Materials Research Vols. 150-151

Abstract: This paper aims at making a study on the bonding properties of birch with API adhesive. A non-formaldehyde adhesive to improve the bonding strength and water resistance of the emulsion was investigated. The adhesive was a composite system that was formulated from polyvinyl acetate (PVAc) emulsion, PVA, isocyanate and some other additives. In this study the effect of isocyanate at room temperature on the curing behavior of PVAc was investigated. A XPS technique has been established to analyze structure of crosslinking in bonding interface. The experimental results indicated that the occurrence for chemical reaction between PVAc-based API adhesive and birch wood.

Abstract: Recycled waste polystyrene foam can be used as heat-resistant construction material, which helps reduce white pollution, benefit the renewability of resources, and brings a good economic and environmental return. Here in this paper, polystyrene foamy particle is used as filling material for the making of non-autoclave aerated concrete, which has good performance with heat reservation and sound insulation.

Abstract: The polyethylene/montmorillonite (PE/MMT) nanocomposites were prepared by melt blending the organic MMT with the ternary-monomer graft copolymers of polyethylene (GPE) which were prepared by solid phase grafting maleic anhydride, methyl methacrylate and butyl acrylate onto PE. Fourier transform infrared spectroscopy was used to characterize the structure of GPE. X-ray diffraction patterns and transmission electron microscopy were used to characterize the morphology of GPE/MMT nanocomposites. Results showed that GPE was an outstanding polymeric material to prepare an exfoliated polymer/layered silicates nanocomposites due to the high polarity of GPE and high graft degree. Most layered silicates still maintain the exfoliated and well dispersed state even at 40 phr OMMT content. The exfoliation of layered silicates was attributed to the well intercalation and easy wetting of the grafted oligomers.

Abstract: Hydrophilic poly((poly(ethylene glycol) methyl ether methacrylate) (P(PEGMA)) brushes were grafted from chloromethylated polyethersulfone (CMPES) hollow fiber membrane surface by surface-initiated atom transfer radical polymerization(SI-ATRP) to improve the membrane’s hydrophilic property. The CMPES hollow fiber membrane was prepared by phase inversion process. The benzyl chloride groups on the CMPES membrane surface could afford effective macroinitiators for grafting the well-defined polymer brushes. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy confirmed the grafting of P (PEGMA) chains. Field emission scanning electron microscopy (FESEM) was used to characterize the surface morphology of the CMPES membrane and modified membrane. The grafting yield of P (PEGMA) was determined by weight gain measurement. The results showed that the number-average molecular weight (Mn) of P (PEGMA) increased with the polymerization time. It was found that the grafting of P (PEGMA) brought higher pure water flux, improved water uptake ratio and better anti-protein absorption ability to CMPES membrane after modification.

Abstract: As a key part in concrete-filled steel tubular frames, the seismic behavior of joints between concrete-filled steel tubes and beams needs more research because of the complexity of stress under the reciprocating load. the behavior of 9 strengthened joints connecting concrete-filled steel tube with H-shaped steel beam have been analyzed under reversed cyclic loading condition by using finite element analysis software ANSYS, and the result show that: (1) The ultimate bearing capacity, energy dissipation capacity and ductility of strengthened joint are obvious better than that of ordinary welded joint; (2) Compared to concrete-filled steel tube the ultimate bearing capacity, energy dissipation capacity and ductility of double-layer concrete-filled steel tubes are better; (3) For the joints connecting double-layer concrete-filled steel tubes with beams, the shape of inner tube have certain effect on the ultimate bearing capacity but little on the energy dissipation capacity and ductility. (4) The shape of stiffened plate has significant influence on the ultimate bearing capacity, energy dissipation capacity and ductility of nodes.

Abstract: Polymer concrete (PC), because of its good vibration alleviating properties, is a proper material for elementary machine parts in high-precision machine tools. Strengthening fibers were applied in PC to improve its mechanical properties, and the material obtained is called fiber reinforced polymer concrete (FRPC). The best parameter to estimate the vibration alleviating property is damping ratio. Orthogonal tests were carried out to prepare FRPC specimens with different fibers. How strengthening fibers affect vibration alleviating properties of FRPC was studies basing on the experiment results.

Abstract: Al-NaI radioactive transmutation target was prepared by powder metallurgy. The existing way of the phase of target was analyzed by the application of XRD and its microstructure and morphology was observed by SEM. Then EDS was used for micro-area energy spectrum analysis and the property of target with different NaI was measured and compared. The results show that NaI is uniformly distributed within the aluminum matrix. The relative density and bending strength of transmutation targets decrease with the increasing content of NaI. The hardness and electrical resistivity of transmutation targets increase with the increasing content of NaI.

Abstract: The influence of mixing fly ash, admixture(including pumping agent, water reducing agent, air-entraining agent), polypropylene fiber on plastic shrinkage of ultra-fine sand pumping concrete by using slab test in this paper. The results show that mixing fly ash can significantly reduce plastic crack area of ultra-fine sand pumping concrete, and plastic crack area begins to reduce slowly when the content of fly ash is up to 20%; When the content of water reducing agent is between 0% and 1.5%, inhibition effects of water reducing agent on plastic shrinkage of ultra-fine sand pumping concrete increase gradually with the content., and the optimum content of water reducing agent is 0.75%; Compared with the water reducer, the effect of mixing pumping agent or air-entraining agent is better; Mixing polypropylene fiber can reduce plastic crack area of ultra-fine sand pumping concrete, slenderizing the crack, and the effect becomes greater with the content of polypropylene fiber.

Abstract: The performance of two kinds of functional polymers were evaluated by lab experiments. Furthermore, relationship between viscosity and concentration, viscosity stability, flow characteristics of two kinds of functional polymers are studied. The results show that two functional polymers have a higher viscosity at different concentrations. The viscosity of functional polymer increases with the time. Flow characteristics show that functional polymers have a higher drag coefficient and residual resistance factor. Meanwhile, we conducted displacement efficiency experiments and expand swept volume experiments. The studies show that two kinds of functional polymer provide significant improvement in displacement efficiency, and after conventional polymer flooding, it also can expand swept volume of low permeability layers effectively.

Abstract: Surface structure and mechanical properties of BaTiO3 thin films prepared by sol-gel process were investigated by XP-2 profiler and nano-indention. The results indicated that the thickness of thin films got thicker with sintering temperature and the thickness-increasing rate differ from different solvent. The hardness and elastic modulus were enhanced due to the presence of residual stress which was compression and probably induced by fabrication method. The maximum hardness is 9.98GPa when the Young’s modulus is 127.41GPa with ethanol as solvent sintered at 1000oC.