Advanced Materials Research Vols. 123-125

Abstract: In order to increase polarity and widen application of natural rubber, the natural rubber (NR) was modified by graft copolymerization with methyl methacrylate (MMA) and glycidyl methacrylate (GMA). The grafting reaction was carried out using emulsion polymerization at 40°C. Redox initiator was used to initiate polymerization. Weight percentage ratio of MMA to GMA was firstly fixed at 90/10 in order to study the effects of amount of initiator and monomer mixture-to-rubber ratio on grafting efficiency [GE(%)] and percentage conversion of monomer (%conversion). The graft copolymerization condition that showed the highest grafting efficiency was chosen to study the effect of MMA-to-GMA ratio. It was found that the highest grafting efficiency [GE(%) = 85.11] were obtained when 1 part of NR, 0.75 part of monomer mixture and 1 phr of initiator were used. 1H-NMR spectrum of the graft copolymer with grafting efficiency of 85.11% illustrated that main monomer grafted onto NR chain was MMA. However, there was a signal of GMA that attached onto the NR chain. The results from an adjustment of MMA-to-GMA ratio showed that grafting efficiency tended to decrease with increasing the amount of GMA. On the other hand, an adjustment of MMA-to-GMA ratio did not significantly affect %conversion.

Abstract: Casein was grafting modified by caprolactam, acrylic esters, vinyl acetate and organic silicon,in order to improve the film-forming defects of casein such as hard, brittle and excessive moisture absorption performance,etc.In this paper, emulsion properties and film-forming performances were taken as the main indexes to inspect the influence of the type and dosage of organic silicon on the final modified casein resin ,results showed that modified casein could be granted more superior water resistance, smoothness and softness with introducing a relative more amount of A-151. Meanwhile, the structure of modified casein were characterized by FT-IR and TEM, results indicated that: grafting copolymerization between casein and grafted monomers did happen actually.

Abstract: Nowadays, many economist and scientist worried for sharply increased to fuel consumption. Developed and developing countries investigation new energy system. It is base on the low emission gas, high energy efficiency, permanence and cogeneration. Specially, transportation system has restricted to system’s total weight. It is concern with light weight offer to increase to performance by itself. And give to other benefit that reduce to oil consumption, improved fuel economy, engine downsizing and increased to Market-value. Fuel cell is one of the new energy systems for next generation. Normally, fuel cell is consisting of bipolar plate, MEA (Membrane Electrode Assembly) and GDL (Gas Diffusion Layer). Conventional bipolar plate material was applied Graphite. Graphite has very weak for external shock, machining process is not easy, and the main problem is that the graphite material supplied by oxidizing and reducing agent composition of the gas leak comes. Thus, by this reason, the manufacturing cost is increased. In this study, to replace the graphite material was selected as a metal material. In this experiment, STS304 austenite base stainless steel is used. This study was based on the metal material’s corrosion behavior observed with 2 type’s surface pretreatment on the STS304 with similar PEMFC operating condition. Experimental results, As-Polished condition has good corrosion resistance better than As-Received condition. It was concerned with passivation layer.

Abstract: An intercalation nonlinear-optical (NLO) polyimide was synthesized based on the 3,3’, 4,4’- Bisphenyltetracarboxylic (BPDA) and [(6-nitrobenzothiazole-2-yl)diazenyl]phenyl-1,3- diamine (NBADA). Then, hybrid polymer was synthesized by the sol-gel technique. FT-IR spectroscopy and 29Si NMR were used to characterize the structure of the hybrid. The results revealed that Q3, Q4 and T3 are the major microstructure elements in forming a network structure. The surface morphology, particle size, crystallinity and the thermal stability of the hybrid were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). DSC and TGA results showed that the glass transition temperature (Tg) and the decomposition temperature (Td) at 5% mass loss were 243, 359°C and 355, 456°C, respectively. These results showed that the hybrid material had excellent thermal stability than the pure polyimide. The electro-optic coefficients of nonlinear optical polyimide and hybrid were measured at the wavelength of 832 nm. The electro-optic coefficients were 22 and 19pm/V (poling voltage of 3.8KV, 210°C) and the values remained well (retained＞93% for more than 100h). The results suggest that the materials have potential applications for high performance optical device.

Abstract: In this paper, we developed a simple and effective method to fabricate lead oxide plate films by electrochemical deposition. The electrolyte was lead nitrate aqueous solution with or without Cl- ions. Stainless steel plate was employed as both cathode and substrate, and a graphite plate as anode. We found the optimal current density of synthesizing lead oxide plate films is 10-25mA/cm2 when there were no Cl- ions in the electrolyte. If equal Cl- ions were added in lead nitrate aqueous solution, the optimal current density of synthesizing lead oxide plate films is less than 10mA/cm2. The as-prepared lead oxide plate films have orthorhombic crystals structure.

Abstract: This paper reports on the development and spectral results of Eu3+ and Tb3+ ions doped zinc lithium boro tellurite glasses in the following composition: 20TeO2 - (60-x) B2O3 -10 ZnO-10Li2O-x Eu2O3 20TeO2 - (60-x) B2O3 -10 ZnO-10Li2O-x Tb4O7 (where x= 0.125, 0.25, 0.375, 0.5 , 0.625 mol %) The measured emission spectrum of Eu3+ glass have revealed five transitions (5D0→7F0, 7F1, 7F2, 7F3 & 7F4) at 578 nm, 592 nm, 612 nm, 643 nm, 701 nm respectively with λexci=392 nm (7F0→5L6) .In the case of Tb3+ glasses four emission transitions such as (5D4→ 7F6, 7F5,7 F4 & 7F3) that are located at 488 nm, 543 nm, 583 nm and 614nm respectively have been measured with λexci=376 nm. For all these emission bands decay curves have been plotted to evaluate their life times.

Abstract: A series of diallyl methyl alkyl ammonium bromide(CCx, X is alkyl’s chain length，represent 12，14，16 and 18 respectively) was synthesized via two step. Monomer was determined by element analysis，NMR，and FT-IR. Organic montmorillonite was prepared by sodium montmorillonite and CCx as intercalating agent. Montmorillonite modified with CCx (CCx-MMT) was indicated by XRD, FT-IR and thermogravimetric analysis (TGA).The XRD results showed that a series of CCx could intercalate into the clay interlayer. XRD and TGA results show that the d spacing of the CCx-MMT was deviated from the linear relationship with TGA organic composition. FT-IR results indicated that the water absorption on the surface of CCx-MMT was effectively restricted and the hydrophobic was increased dramatically. The variety peak intensity at 2924 and 2854cm−1 was consistent with content of organic fraction in CCx-MMT.

Abstract: Modified rapeseed oil(MRO) was prepared by using rapeseed oil, ethylene diamine and acrylic acid as the raw materials. Modified rapeseed oil/montmorillonite(MRO/MMT) nanocomposite was prepared by using modified rapeseed oil and montmorillonite. The emulsifying properties of MRO and MRO/MMT were determined respectively. Fourier transforms infrared spectrometry (FT-IR) and Transmission Electron microscope (TEM) results showed that MRO/MMT was prepared successfully. X-ray diffraction (XRD) results showed that modified rapeseed oil could smoothly enter the interlayer of montmorillonite, and modified the montmorillonite; with an increase in the amount of montmorillonite, the layer spacing of montmorillonite in the MRO/MMT lower after the first increase. The results of emulsifying properties indicated that emulsifying properties of MRO/MMT was better than MRO.

Abstract: Novel flower-like silica microstructures have been synthesized through heating silicon, silicon monoxide and active carbon mixed powders under an H2/Ar (3%) atmosphere at 1050°C without assistance of any metal catalyst. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and energy dispersive x-ray spectrometer (EDS) analyses reveal that the wires are amorphous and consist only of silicon oxide, generated from the reaction of CO with SiC. A possible growth model based on both of vapor-solid (VS) and the Oxide-assisted growth (OAG) mechanism has been supposed here to explain this phenomenon.