Advanced Materials Research Vols. 284-286

Abstract: Texutre evolution of 1235 aluminum alloy deformed at different strain rates was studied by dynamic thermal-simulated technology with the aid of some modern analytical and testing technique called election backscatter diffraction (EBSD). The results showed that the effect of strain rate on grain boundary and deformation texture of 1235 aluminum alloy was obvious. At deformation temperature for 400°C and distortion for 50%, the value of the maximum density level came to the minimum by 11.489 at the strain rate for 0.01s^-1. The texture was weaker for the grains were less likely to rotate. The relative volume of textures increased as the strain rate increasing. The relative volume of textures was merely 1.95% at strain rate for 0.01s^-1 but ascended to 5.4% at strain rate for 50s^-1.

Abstract: The effects of bismuth on the mechanical properties of magnesium alloy AZ81 have been investigated. The results show that the addition of 1wt.% bismuth can improve the morphology of β-Mg₁₇Al₁₂ phase, cause the formation of Mg₃Bi₂ phase, and enhance the mechanical properties of magnesium alloy AZ81 at room temperature and 150°C.

Abstract: Hot ductility of ML40Cr steel at the temperatures from 700°C to 1300°C was measured on simulator Gleeble-1500. The results are as follows: the hot ductility reduces in temperature range of 950°C to 1300°C, and increases in temperature range of 700°C to 950°C. The reduction of cross section area is reduced obvious in temperature range of 950°C to 1300°C, and Extensibility fall is slow. The best hot ductility of ML40Cr steel is 950°C.

Abstract: The corrosion behavior of Al-5Zn-0.03In and Al-5Zn-0.03Ga alloys in 3.5 % NaCl solution has been examined by electrochemical methods, scanning electron microscopy, X-ray microanalysis, electrochemical impedance spectroscopy. The results demonstrate that the alloys differ in the microstructure, corroded morphology and electrochemical properties. For Al-5Zn-0.03In alloy, the precipitates enriched in Al and Zn initiates pitting. For Al-5Zn-0.03Ga alloy, corrosion occurs more uniformly, the corrosion of the alloy occurred via the formation of a surface Ga-Al amalgam alloy. The EIS of Al-5Zn-0.03In alloy contains a capacitive loop and an inductive loop; the inductive loop can be attributed to the presence of the pitting. The EIS of Al-5Zn-0.03Ga alloy contains only a capacitive loop.

Abstract: Miscibility of ternary polymer blends composed of poly(ethyleneimine) (PEI), poly(ethylene glycol) (PEG), and carboxymethyl chitosan (CMCS) was investigated by dilute-solution viscometry, FTIR spectrum, and scanning electron microscope (SEM) techniques. The results of these measurements indicate that PEG is immiscible in the ternary CMCS/PEI/PEG polymer blend.

Abstract: Chitosan-g-MMA was prepared with methyl methacrylate using ceric ammonium nitrate (CAN) as an initiator under nitrogen atmosphere in aqueous solution and characterized by FTIR spectroscopy. The effects of concentration of CAN, the amount of MMA, reaction temperature on graft copolymerization were studied by determining the grafting percentage and grafting efficiency. The maximum grafting percentage and grafting efficiency obtained under these conditions were 790 % and 83 %, respectively.

Abstract: PMMA-b-PDMAEMA/polysulfone composite membranes for CO₂ separation was prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization techniques. The chemical composition and structure of the polymers were characterized by Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR), and molecular weight and its distribution were measured by Gel permeation chromatography (GPC). CO₂ permeation performance of the PMMA-b-PDMAEMA/ polysulfone composite membranes was test. The results showed that the resulted composited membrane posses good permeation performance for CO₂.

Abstract: Thermalstability of polyclonal antibodies to Salmonella typhimurium was investigated by studying the effect of temperature on the binding activity to Salmonella typhimurium using a magnetostrictive platform. Antibodies were immobilized using the Langmuir-Blodgett (LB) technique. Then sensors were stored at temperatures of, 25°C (room temperature), 45°C and 65°C, respectively, and then the ability of these sensors to detect S. typhimurium was tested at a predetermined schedule. Changes in the fundamental resonance frequency of sensors after exposure to 1 ml of 1×10⁹cfu/ml of S. typhimurium were recorded over the testing period. The shift in resonance frequency was attributed to the binding of bacteria to antibody immobilized sensor. The results showed that at each temperature, the binding ability of the antibody to S. typhimurium decreased gradually over the testing period, and the higher the temperature, the lower the longevity of the polyclonal antibody. The longevity of polyclonal antibody on the magnetostrictive sensor platform was about 30, 8 and 5 days at room temperature (25°C), 45°C and 65°C, respectively.

Abstract: A series of polyesteramide containing 5-fluorouracil in the main chain were prepared by reacting potassium salt of 5-fluorouracil with N-(2-chloroacetoxylalkyl)-chloroacetamide.The copolymers were characterized by FT-IR, ¹H-NMR, VPO and UV spectroscopy. The drug release profile in vitro of the copolymers were studied, the results showed prodrug could slow release 5-FU or 5-FU units in different solution, they may be likely to become potential antitumor prodrug.

Abstract: The samples were modified by using chlorinated polyethylene (CPE) to increase the toughness and using dioctyl phthalate (DOP) to increase the plasticity. The tensile strength and breaking elongation of the samples were studied by changing the chlorinated polyethylene (CPE) and dioctyl phthalate (DOP) contents and the hot-pressing temperature. It was shown by the test results that, with the increase of chlorinated polyethylene (CPE) and dioctyl phthalate (DOP) contents, the tensile strength of the samples was decreased while the breaking elongation was increased. By increasing the hot-pressing temperature, the blending effect between polyvinyl chloride (PVC) and chlorinated polyethylene (CPE) as well as the mechanical performance of the samples were increased, however, over-high hot-pressing temperature would result in plasticizer precipitation.