PU软段结构对PU／PMMA IPN中两组分相容性的影响

用同步法合成了４种聚氨酯／聚甲基两烯酸甲酯互穿聚合物网络（ＰＵ／ＰＭＭＡＩＰＮ），利用ＤＤＣ、ＴＥＭ和动态力学谱（ＤＭＳ）等手段综合研究了ＩＰＮ中两组分的相容性和相态结构，用基团贡献加和方法计算了各种ＰＵ和ＰＭＭＡ的溶度参数δ，结合ＰＵ软段链结构讨论了各种ＩＰＮ呈现不同相容性和相态结构的原因。

Structure characteristic and its evolution of Cu-W films prepared by dual-target magnetron sputtering deposition

Immiscible Cu-W alloy thin films were prepared using dual-target magnetron sputtering deposition process. The structure evolution of Cu-W thin films during preparation was investigated by X-ray diffraction, transmission electron microscopy and high resolution transmission electron microscopy. In the initial stage of dual-target magnetron sputtering deposition process, an amorphous phase formed; then it crystallized and the analogy spinodal structure formed due to the bombardment of the sputtered particles during sputtering deposition process, the surface structure of the film without the bombardment of the sputtered particles was the amorphous one, the distribution of the crystalline and amorphous phase showed layer structure. The solid solubility with the analogy spinodal structure was calculated using the Vegard law. For Cu-13.7%W （mole fraction） film, its structure was composed of Cu-ll%W solution, Cu-37%W solution and pure Cu; for Cu 14.3%W film, it was composed of Cu-15%W solution, Cu-38%W solution, and pure Cu; for Cu-18.1%W film, it was composed of Cu-19%W solution, Cu-36% W solution and pure Cu.

Transformation of microstructure and phase of disodium guanosine 5′-monophosphate: Thermodynamic perspectives

Microstructure and phase transformation of disodium guanosine 5′-monophosphate(5′-GMPNa_2) are extremely important for controlling the process and understanding the mechanism of crystallization. In this work, the thermodynamic properties of polymorphous 5′-GMPNa_2 especially the solubility were studied, the solubility results show that 5′-GMPNa_2 is more soluble in ethanol–water(E–W) than in isopropanol–water(I–W). The amorphous form of 5′-GMPNa_2 is more soluble than the crystalline form at the same mole fraction and temperature. Meanwhile, the crystalline forms and morphologies of the residual solids were characterized by PXRD and SEM. The results indicate that solid forms of 5′-GMPNa_2 transformed spontaneously from amorphous to crystalline when the ethanol proportion is ≥20%. In addition, increasing the pH facilitates the dissolution of 5′-GMPNa_2 and helps to maintain the crystalline form. The associated Gibbs free energy values were calculated to verify the trend of transformation from amorphous to crystalline 5′-GMPNa_2. These results should help to guide the industrial crystallization process and to obtain the crystalline form of 5′-GMPNa_2.

Corrosion properties of plastically deformed AZ80 magnesium alloy

AZ80 magnesium alloys were deformed at 200,250,300,350 and 400℃ with different deformation degree of 50%,75%, 83%,87%and 90%,respectively.The corrosion properties of different deformed AZ80 samples were studied by galvanic test in 3.5%NaCl solution.The results show that plastic deformation could improve the corrosion resistance of AZ80 alloy;and the corrosion rate of AZ80 deformed at 250℃ with the deformation degree of 83%was the lowest,which was 33%of the as-cast AZ80 alloy.Further studies of the microstructure show that the refined grain size and continuously distribution ofβphase around the grain boundary did have a positive effect on the improvement of corrosion resistance of AZ80 alloys.For AZ80 alloys,the smaller the grain size is,the more homogeneous the structure is,and the better the corrosion resistance is.

Observation of material fluxes through the Luzon Strait

Based on field observations carried out in August, 2008, we obtained a set of data on velocity, hydrography, and hydroehemistry in the Luzon Strait, with which the velocity structure of the area, especially in deep channels, was analyzed, and the material fluxes, including water, dissolved oxygen, and nutrients were calculated. The results indicate that a net eastward water flux of 7.0 Sv occurred through the Luzon Strait. The deep layer flux in the southern part, through the deep channel, was westward with a value of 1.9 Sv, which confirms that deep Pacific water flows into the South China Sea via the deep passage in the Luzon Strait. Accordingly, the net flux of dissolved oxygen was 13.2× 10 5 mol/s, and the values for dissolved inorganic nitrogen, phosphate and silicate were 4.6× 10 4 mol/s, 2.4× 10 3 mol/s, and 8.9×10 4 mol/s, respectively. Detailed descriptions of these material fluxes in the upper layer, the upper-intermediate layer, the lower-intermediate layer, and the deep layer through the Luzon Strait are discussed. These results and interpretations highlight the importance of material exchanges between the South China Sea and the Pacific Ocean.

The Flow Behavior of Poly(m-Phenyleneisophthalamide) Concentrated Solution

By means of HAAKE RS105L cone and plate rheometer the concentrated solution, including viscous flow activation energy, non-Newtonian index, structural viscosity index and relaxation time of the PMIA solution were studied. The effect of concentration and temperature of the solution and molecular weight of the polymer on its non-Newtonian behavior was investigated. The results showed that PMIA concentrated solution prepared via low temperature condensation was of non-Newtonian fluid. With the decrease of temperature, increase of solution concentration and PMIA molecular weight, the deviation of the solution from Newtonian behavior decreased. The molecular weight of the polymer and the concentration of the solution affected the non- Newtonian behavior mete intensively.

Formation of Polyethersulfone Film with Regular Microporous Structure by Water Vapor Induced Phase Separation

Polyethersulfone(PES)film with regular microporous structure was formed using dichloromethane as the solvent via water vapor induced phase separation(VIPS).The effects of solution concentration,atmospheric humidity and temperature,as well as molecular weight of PES on the surface morphology of the polymer film were investigated.The surface morphology characterized by SEM showed that the pore size reduced as the solution concentration increased.There was an optimum range of relative humidity for the formation of regular pore structure, which was from 60%to 90%at concentration of 20 g·L-1 and 20°C.With the atmospheric temperature varied from 20 to 30°C,the pore became larger and the space between pores increased.The pore size in the PES film with low molecular weight was smaller than that with high molecular weight.

Scaling Theory of Polyelectrolyte Nanogels

The present paper develops the scaling theory of polyelectrolyte nanogels in dilute and semidilute solutions. The dependencies of the nanogel dimension on branching topology, charge fraction, subchain length, segment number, solution concentration are obtained. For a single polyeleetrolyte nanogel in salt free solution, the nanogel may be swelled by the Coulombie repulsion （the so-called polyelectrolyte regime） or the osmotic eounterion pressure （the so-called osmotic regime）. Characteristics and boundaries between different regimes of a single polyelectrolyte nanogel are summarized. In dilute solution, the nanogels in polyeleetrolyte regime will distribute orderly with the increase of concentration. While the nanogels in osmotic regime will always distribute randomly. Different concentration dependencies of the size of a nanogel in polyeleetrolyte regime and in osmotic regime are also explored.