PEO-12-钨磷酸质子导电聚合物电解质膜

以聚氧乙烯(PEO)为基质, 在其中掺杂适量的钨磷酸, 制备PEO-H₃PW₁₂O₄₀质子导电聚合物电解质膜. XRD及IR测试表明体系中Keggin阴离子与PEO链相互作用形成新的化合物; Keggin阴离子的存在有利于水合质子的形成. PEO-H₃PW₁₂O₄₀复合膜的电导率室温最高可达4.0×10^－3 S•cm^－1.     

含双键侧基的聚氧乙烯与苯乙烯的接枝共聚物及其产物的性质

由环氧乙烷及烯丙基缩水甘油醚合成含双键侧基的聚氧乙烯用苯乙烯接枝共聚,接枝效率可达50％左右.接枝产物经纯化,用IR及~1H NMR表征.该产物与LiClO_4的络合物有较高的室温导电率,其PEO含量在70％及EO/Li=20/1时,25℃的导电率接近10~(-4)S/cm.此外,该接枝共聚物有较高的乳化能力.在Williamson固液反应中具有良好的相转移催化作用.     

MODIFICATION OF TRANSITION METAL CATIONS TO POLYMER-STABILIZED PLATINUM COLLOIDAL CLUSTERS IN ENANTIOSELECTIVE HYDROGENATION OF METHYL PYRUVATE

Modification of transition metal cations to polymer-stabilized Pt colloidal clusters modified with cinchonidine was studied in enantioselective hydrogenation of methyl pyruvate. Compared to the enantiomeric excess (e.e.) value (71.4%) obtained without the presence of metal cations, obvious e.e. enhancement (up to 82.5%) was resulted from the addition of Zn^2 but with a certain decrease in activity. The reaction parameters in the presence of Zn^2 were also studied. It was found that the Pt colloidal catalysts in the presence of metal cations performed very differently from that in the absence of metal cations.     

A Novel Cu-Mo／ZSM-5 Catalyst for NOx Catalytic Reduction with Ammonia

The Cu-Mo/ZSM-5 catalysts with different Cu/Mo ratios were prepared by wet impregnation method, and their catalytic performance for selective catalytic reduction of NOx was studied. The results showed that Cu-Mo/ZSM-5 is a very effective catalyst for NOx catalytic reduction with ammonia, especially when Cu/Mo molar ratio is about 1.5. It not only exhibited the extremely high catalytic activity, but also showed good stability for 02. The bulk phase structure of Cu-Mo/ZSM-5 catalysts was determined by XRD technique, and the results indicated that there is a maximum dispersion for Cu species when Cu/Mo molar ratio is 1.5, and an interaction between Cu and Mo along with HZSM-5 may be present in Cu-Mo/ZSM-5, which may possibly result in a special structure favorable for the catalytic reduction of NOx over Cu-Mo/ZSM-5 catalyst.     

PVDF／PAN共混超滤膜

ＰＶＤＦ／ＰＡＮ共混超滤膜尹秀丽＊宋艳秋（天津纺织工学院材料科学系天津３００１６０）关键词聚偏氟乙烯，聚丙烯腈，共混，超滤膜１９９６－１１－２０收稿，１９９７－０５－０７修回共混是改变高分子材料性能的重要手段，已发现用聚合物共混的方法能制得性能优异的...     

Highly Stereoselective Synthesis of trans-3-Aryl-4-carbethoxy-2,3-dihydro-2-fur-2＇-oyl-5-methylfurans

Multi-substituted dihydrofurans are valuable intermediates for the synthesis of natural products and pharmaceuticals. Considerable attention has been focused on the development of efficient and regioselective methods for their preparation. Using K2CO3 as a base, with the reaction of fur-2-oylmethyltriphenylarsonium bromide 1 and ethyl 2-acetyl-3-arylacrylate 2 in tetrahydrofuran at room temperature, we found an efficient protocol was achieved to synthesize trans-3-aryl-4-carbethoxy-2,3-dihydro-2-fur-2＇-oyl-5-methylfurans 3 in good yield with high stereoselectivity. The structure of compound 3 was confirmed by IR, ^1H NMR, MS and HRMS. The mechanism for the formation of 3 was proposed.     

过渡金属离子对HPAsMoVO杂多酸的氧化性能的影响

用H2-TPR方法研究了过渡金属离子及其含量对杂多酸-HxPAs0.2Mo10VOy的氧化性能的影响,并在固定床反应器上考察了M0.2HxPAs0.2Mo10VOy(M=Fe3 、Co2 、N i2 和Cu2 )催化剂对异丁烷选择性氧化的催化性能.研究结果表明用过渡金属离子取代杂多酸中的质子,可以在较大程度上增强杂多酸的低温氧化能力,其中Fe3 对增强杂多酸的催化活性最为明显,而Cu2 却有利于提高目的产物甲基丙烯酸的选择性.     

锆氢化反应研究2.羰基化合物的选择性还原

本文对芳香醛和酮的锆氢化反应及水解产物进行了研究。产物经NMR证明为相应的醇。并以苯甲醛为代表,初步探讨了锆氢化反应的过程。还研究了含有其他官能团的苯甲醛对锆氢化反应选择性的影响,以及含有较大取代基酮类的锆氢化反应。     

双功能催化剂体系作用下乙烯二聚和共聚合的研究

用乙烯为原料在双功能催化剂体系的作用下通过二聚和共聚合反应，直接合成线性低密度聚乙烯（ＬＬＤＰＥ）．所用二聚反应催化剂为钛酸正丁酯（Ｔｉ（ＯＢｕ）_４），共聚催化剂为ＴｉＣｌ_４／ＭｇＣｌ_２（ＺＭ－１催化剂）．研究了二聚反应动力学行为及影响双功能催化剂体系动力学过程的一些因素．结果表明利用这两种催化剂组成双功能催化剂体系能够很方便地制得密度范围在０．９０－０．９３，Ｅｔ／１０００Ｃ在１０－４０的ＬＬＤＰＥ．     

立体选择性合成2-呋喃甲酰基-3-芳基-4-乙氧羰基-5-甲基-反式-2,3-二氢呋喃

溴化呋喃甲酰基甲基三苯鉮1与2-乙酰基-3-芳基丙烯酸乙酯2以碳酸钾为碱，在四氢呋喃中室温反应，可以较好的收率、高立体选择性地生成反-2-呋喃甲酰基-3-芳基-4-乙氧羰基-5-甲基-2,3-二氢呋喃3。产物结构均经波谱予以确定。本文还提出了生成产物的可能机理。