共混改性ACS合金的性能形态与流变性研究

利用增容原理,以α－甲基苯乙烯,丙烯酸酯为单容改性单体,与苯乙烯,丙烯腈乳液共聚,所得共聚物与氯化聚乙烯共混得ＡＣＳ合金,研究了以α－甲基苯乙烯,丙烯酸乙酯用量对ＡＣＳ合金力学性能,流变性的影响,同时考察了树脂的微观结构与形态。     

苯乙烯－丁二烯－苯乙烯工嵌段共聚物／聚（苯乙烯－甲基丙烯酸盐）热塑性IPN中离子聚集结构的研究

苯乙烯－丁二烯－苯乙烯工嵌段共聚物／聚（苯乙烯－甲基丙烯酸盐）热塑性ＩＰＮ中离子聚集结构的研究韦雨春，袁惠根，潘祖仁（浙江大学化工系杭州３１００２７）关键词互穿聚合物网络，离子聚集，远红外光谱，Ｘ－光散射以苯乙烯－丁二烯－苯乙烯三嵌段共聚物（ＳＢＳ）...     

聚己内酯和丙烯腈-苯乙烯无规共聚物的共混物生成环带球晶中的几个新现象

聚己内酯（ＰＣＬ）和丙烯腈－苯乙烯无规共聚物（ＳＡＮ）的共混物的相容性和形态曾被广泛研究［１～４］．ＰＣＬ的结晶形成球晶结构，其和ＳＡＮ共混，在熔体中结晶时不但可观察到Ｍａｌ－ｔｅｓｅ十字消光，而且存在非常明显的明暗交替的周期性环带状结构，称之为“环...     

以阳离子乳化剂进行丙烯酸丁酯－苯乙烯乳液共聚的动力学研究

采用十二烷基二甲基苄基氯化铵（１２２７）乳化剂，对丙烯酸丁酯（ＢＡ）－苯乙烯（Ｓｔ）进行乳液共聚，研究了影响聚合速度的各种因素，得出了聚合速率方程和表观活化能．     

含有机硅三元多嵌段共聚物的研究──Ⅱ．（PSF－PDMS－PHS）_n的动态力学性能研究

以双酚Ａ聚砜（ＰＳＦ）为硬段、聚对羟基苯乙烯（ＰＨＳ）为半硬段、聚二甲基硅氧烷（ＰＤＭＳ）为软段合成了三元多嵌段共聚物，并对其动态力学性能和抗张性能进行了比较详细的研究，结果表明该三元多嵌段共聚物为多相结构；在引入半硬段ＰＨＳ后两相间的界面相增宽，粘接力增大，其强度和模量高且稳定，使含有机硅高分子材料强度低的弱点得以改善。扭辩分析（ＴＢＡ）结果显示，这种三元多嵌段共聚物具有多重转变，且在－２０℃至５０℃间有两个较大的几乎重叠的吸收峰；这表明这种三元多嵌段共聚物的相分离结构较为复杂，并有良好的阻尼性能。     

以阳离子乳化剂进行丙烯酸丁酯－苯乙烯乳液共聚的动力学研究

采用十二烷基二甲基苄基氯化铵（１２２７）乳化剂，对丙烯酸丁酯（ＢＡ）－苯乙烯（Ｓｔ）进行乳液共聚，研究了影响聚合速度的各种因素，得出了聚合速率方程和表观活化能。     

用SN型催化剂合成苯乙烯－丙烯嵌段共聚物的研究II．共聚物的结构表征与性能

报道用稀土化合物改性的钛系截体催化剂（ＳＮ催化剂）进行苯乙烯和丙烯顺序嵌段共聚合（Ｓｅｑｕｅｎｔｉａｌｂｌｏｃｋｃｏｐｏｌｙｍｅｒｉｚａｔｉｏｎ）的研究，通过对初生嵌段共聚产物进行溶剂萃取与分级，并用１３Ｃ－ＮＭＲ、ＷＡＸＤ．ＤＳＣ，ＤＭＡ和电子显微镜进行表征，推断共聚物为具有等规聚苯乙烯链和等规聚丙烯链段的Ａ－Ｂ型二嵌段共聚物，且各段均能结晶。发现嵌段共聚物比相应的均聚物具有较好的综合力学性能和热性能，而且对ｉＰＳ／ｉＰＰ共混具有良好的增容作用。     

丙烯酰胺－丙烯酸甲酯－2－丙烯酰胺基－2－甲基丙磺酸共聚物的合成及表征

以丙烯酰胺（ＡＭ），丙烯酸甲酯（ＭＡ）和２－丙烯酰胺基－２－甲基丙磺酸（ＡＭＰＳ）为原料，通过水溶液共聚，合成了一种新的三元共聚物。研究了影响共聚反应的因素，并对其结构进行了表征。     

苯乙烯—丙烯嵌段共聚物等温结晶动力不宾研究

用ＤＳＣ法研究苯乙烯－丙烯嵌段共聚物（ｉＰＳ－ｂ－ｉＰＰ）的等温结晶动力学，结果表明，在所选择的结晶温度（１２７－１３２℃）范围内，共聚物很好地符合Ａｖｒａｍｉ动力学方程；共聚物结晶温度，结晶速率，结晶成和生长方式都与共聚物结构和组成比在关，随着嵌段共的中ｉＰＳ段含量的增加，结晶速率和Ａｖｒａｍｉ指数（ｎ）明显降低。     

聚氨酯／聚（苯乙烯－甲基丙烯酸甲酯－甲基丙烯酸）互穿聚合物网络的研究

研究了（蓖麻油－聚乙二醇）聚氨酯／聚（苯乙烯－甲基丙烯酸甲酯－甲基丙烯酸）（ＰＵ／Ｐ（Ｓｔ－ＭＭＡ－ＭＡＡ））互穿聚合物网络（ＩＰＮ）．动态力学性能及透射电镜结果均表明该体系相分离较严重；ＩＰＮ具有两个玻璃化转变温度，它们有不同程度的内移，形成一定程度分子水平的混合，而ＩＰＮ（５０／５０）其分子混合水平较大，互穿缠结程度较高。形成ＩＰＮ后，其力学性能得以改善。透射电镜结果表明，聚氨酯网的交联密度直接影响ＩＰＮ的相区尺寸。形成ＩＰＮ后热稳定性提高，易于降解断链的Ｓｔ－ＭＭＡ－ＭＡＡ单体起到了自由基消除剂的作用。     

Solvent extraction separation of In/III/-Tl/III/ and Hg/II/-Cd/II/-Co/II/ with sulphoxides

Solvent extraction studies have been made on some metals: In/III/-Tl/III/ and Hg/II/-Cd/II/-Co/II/, from ammonium thiocyanate solutions by dialkyl sulphoxides. Separation of these metals from one another can be achieved by suitable choice of the extracted conditions. The nature of the extractable metal species has been elucidated.     

Synthesis of chlorobis/β-diketonato/oxotechnetium/V/ and tris/β-diketonato/technetium/III/ complexes

Chlorobis/-diketonato/ oxotechnetium/V/ complexes [TcOCl/-dik/₂, -diketone=acetylacetone, benzoylacetone and dibenzoylmethane] were newly synthesized using macroamount of⁹⁹Tc. These complexes were further separated into geometrical isomers. Furthermore, an improvement of the yields for the syntheses of tris/-dike-tonato/technetium/III/ complexes [Tc/-dik/₃, -diketone=acetylacetone, benzoylacetone and 2-thenoyltrifluoroacetone] was examined using Tc/III/-thiourea complexes as a starting material.     

Direct synthesis of dimethyl carbonate ?from CH3OH AND CO2 by H3PW12O40/CexTi1-xO2 catalyst

Summary Ce_xTi_1-xO₂ and H₃PW₁₂O₄₀/Ce_xTi_1-xO₂ catalysts were prepared using a sol-gel method, and applied to the direct synthesis of dimethyl carbonate from methanol and carbon dioxide. H₃PW₁₂O₄₀/Ce_xTi_1-xO₂ showed a better catalytic performance than the corresponding Ce_xTi_1-xO₂, due to the bifunctional catalysis of Br?nsted acid sites (provided by H₃PW₁₂O₄₀) and base sites (provided by Ce_xTi_1-xO₂). H₃PW₁₂O₄₀/Ce_0.1Ti_0.9O₂ showed the highest catalytic performance among the H₃PW₁₂O₄₀/Ce_xTi_1-xO₂ catalysts.     

Simultaneous propane dehydrogenation andco2hydrogenation overCrOx/SiO2catalyst

Summary Single reverse water-gas shift (RWGS) and dehydrogenation of propane with CO₂(DH-CO₂) reactions in the presence and absence of the CrO_x/SiO₂ catalyst have been studied between 673 and 873 K. It was found that the CrO_x/SiO₂ catalyst is active both in the dehydrogenation of propane and in the RWGS reactions. The obtained results suggest that the dehydrogenation of propane to propene in the presence of CO₂on CrO_x/SiO₂can be facilitated by the RWGS reaction.</o:p>     

Crystal structure of Na3PO4 · 12H2O

The crystal structure of trisodium monophosphate hemihydrate was determined. The space group is $\text{C2}\text{c}$ and a unit cell contains eight formula units. The unit cell dimensions of $\text{Na}{}_3\text{PO}{}_4\text{·}\text{1}\text{2}\text{H}{}_2\text{O}$ are a = 9.631(3), b = 5.416(2), c = 16.938(8) Å, β = 102.60(5)°. The final R value is 0.027 for a set of 1430 independent reflections. This atomic arrangement is mainly a three-dimensional network of distorted NaO₆ octahedra. The hydrogen bonding scheme is given.     

LixNi0.8-yCo0.2ZnyOp的合成及电化学性能研究

A series of single-phase Li_xNi_0.8-yCo_0.2Zn_yO_p(0.96 ≤x≤ 1.10， 0 ≤y≤ 0.05， 2 ≤p≤ 2(1+y) ) (different in the y values) were synthesized by a two-step solid state reaction method， in which LiOH·H₂O， Zn-doped spherical Ni(OH)₂ and Co₂O₃ were used as the precursors. The ICP-AES analyses proved that the Zn-doped compounds synthesized had the nonstoichiometric form. The results of the XRD， SEM identified that the uniform particles of the as-prepared materials having a good layered structure were fine， narrowly distributed and well crystallized. The electrochemical performance test was carried out and the results showed that the as-prepared Zn-doped materials had not only a high capacity， but also a better cycling stability characterization than the un-doped one. The Li_1.06Ni_0.75Co_0.22Zn_0.03O_2.03 material has an initial reversible capacity as high as 160.5mAh·g^-1; and a first discharge efficiency 89.2%， and exhibits satisfactory cyclic stability with 90% retainable capacity after 50 cycles.     

An investigation of the promotional effect of propylene or propane traces on the activity of sulfatedPt/g-Al2O3andPt-Sn/g-Al2O3inCH4combustion

Summary A strong promoting effect of the presence of C₃H₈or C₃H₆was determined for the combustion of CH₄in excess oxygen, over pre-sulfated 1%Pt/g-Al₂O₃and pre-sulfated 1%Pt-2%Sn/g-Al₂O₃catalysts.</o:p>     

Synthesis and characterization of Ti1−2xNbxNixO2−x/2 solid solutions

Doped-rutile has been traditionally used in ceramic pigments for its intense optical properties. In this paper, we compare the classical ceramic synthesis of Ti_1−2xNb_xNi_xO_2−x/2 system with the sol-gel methodology, which allows a reduction of the anatase-rutile transformation temperature. The composition was optimised in order to obtain a unique rutile phase with the minimum amount of pollutant Ni(II) and enhanced chromatic coordinates. Incorporation of the doping ions in the rutile structure was corroborated by XRD and Rietveld refinements. The species responsible for the colour mechanism were studied by different techniques. UV-VIS spectroscopy showed the characteristic features of Ni²⁺ ions, whose existence was corroborated by EPR and magnetic measurements. From these results, (Ni,Nb)doped-TiO₂ powder samples can be now shaped as thin films, monoliths, etc. by using sol-gel methodology without modifying their properties. This study introduces new possibilities of coloured TiO₂-based solid solutions in new combined advanced applications (colouring agent and photocatalyst, etc.).     

Visible light-sensitive yellow TiO2−xNx and Fe-N co-doped Ti1−yFeyO2−xNx anatase photocatalysts

Nitrogen substituted yellow colored anatase TiO_2−xN_x and Fe-N co-doped Ti_1−yFe_yO_2−xN_x have been easily synthesized by novel hydrazine method. White anatase TiO_2−δ and N/Fe-N-doped samples are semiconducting and the presence of ESR signals at g ∼1.994-2.0025 supports the oxygen vacancy and g∼4.3 indicates Fe³⁺ in the lattice. TiO_2−xN_x has higher conductivity than TiO_2−x and Fe/Fe-N-doped anatase and the UV absorption edge of white TiO_2−x extends in the visible region in N, Fe and Fe-N co-doped TiO₂, which show, respectively, two band gaps at ∼3.25/2.63, ∼3.31/2.44 and 2.8/2.44 eV. An activation energy of ∼1.8 eV is observed in Arrhenius log resistivity vs. 1/T plots for all samples. All TiO₂ and Fe-doped TiO₂ show low 2-propanol photodegradation activity but have significant NO photodestruction capability, both in UV and visible regions, while standard Degussa P-25 is incapable in destroying NO in the visible region The mid-gap levels that these N and Fe-N-doped TiO₂ consist may cause this discrepancy in their photocatalytic activities.     

LixZryOz三元化合物的制备及表征

采用高温固相法制备了4种高纯度晶相组成的LixZryOz三元化合物,研究了焙烧温度、时间、反应物的种类和初始反应物物质的量比对产物组成的影响,进一步用XRD、SEM及BET分析方法对产物的晶相结构、表面形貌及比表面积进行了表征.实验结果表明,Li2CO3与ZrO2在适当条件下可以合成得到单斜相Li3ZrO3;以LiOH替代Li2CO3,在适当条件下可以分别合成得到四方相Li2ZrO3和三斜/单斜相Li6Zr2O7;进一步以Zr(NO3)4·5H2O代替Zr02,可将单斜相Li6Zr2O7的制备时间由96 h缩短至24 h.SEM照片显示产物硬团聚明显,粒径分布在1～10μm间,BET分析表明样品比表面积处于1.0～9.0 m2·g-1间分布,反应过程中锂的过量以及长时间高温焙烧是引起产物粒径长大和产生硬团聚的主要原因.