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1.
3,4—二氨基呋咱的乙酰化反应   总被引:3,自引:0,他引:3  
李战雄  唐松青  刘金涛 《有机化学》2002,22(11):902-904
研究了3,4—二氨基呋咱(DAF)的乙酰化反应,以DAF和溴乙酰溴缩合时成功地 得到了取代乙酰化呋咱衍生物,而和氯乙酰氯缩合时则发生呋咱环重排反应,两种 反应产物经叠氮化可得到不同的高氮含量含能化合物.文中分析了两种缩合反应中 呋咱环表现不同的原因.  相似文献   

2.
研究了EtOH-H2O,n-PrOH-H2O,i-PrOh-H2O体系在CS膜和PEO/CS共混膜中的渗透蒸发性能。讨论了料液温度、料液浓度、共混膜组成对分离性能的影响,结果发现PEO的掺入能大大提高CS膜的渗透通量,而分离因子下降。同时从膜材料的聚集态结构出发对相关的渗透蒸发行为进行了讨论。对于PEO/CS共混膜,膜内自由体积的大小是影响分离性能的主要因素,小分子在膜中的渗透蒸发行全为主要是由扩  相似文献   

3.
本文报导了聚4-氨基联苯的电化学合成,测定了它的ESR、IR及紫外可见光谱。聚合物在THF、DMF和DMSO中能全部溶解。界面移动法测得聚4-氨基联苯的DMF饱和溶液中正离子的迁移率为1.48×10~(-8)m~2·S~(-1)·V~(-1)。  相似文献   

4.
5.
以带酞基聚芳醚酮(PEKM)为膜材料,用相转换法制备了PEK—C不对称超滤膜,研究了铸膜液的主要组分对膜的孔结构与超滤性能的影响。  相似文献   

6.
N—酰化壳聚糖膜性能的研究   总被引:5,自引:1,他引:5  
讨论了一系列N-酰化壳聚糖膜的抗张强度、透水性、VB_(12)的透过性、透氧性以及血液相容性。N-已酰化壳聚糖膜具有良好的血液相容性。在制膜过程中,加入分子量为1500的聚乙二醇为致孔剂,则可使N-己酰化壳聚糖膜的渗透性有较大提高。同时保持较好的血液相容性和强度。  相似文献   

7.
交联聚氨基壳聚糖螯合树脂的制备及吸附性能研究   总被引:22,自引:0,他引:22  
以壳聚糖为原料合成了交联聚氨基球状螯合树脂,并考察了其对Hg(Ⅱ)、Pb(Ⅱ)、Zn(Ⅱ)的吸附性能及影响因素。结果表明,对高浓度金属离子(约0.01mol/L)吸附量的大小为Hg(Ⅱ)>Pb(Ⅱ)>Zn(Ⅱ),对Zn(Ⅱ)几乎不吸附;而在低浓度时(约20ug/ml)树脂对三种离子均具有较高的吸附率(>55%)。  相似文献   

8.
本文在HClO4介质中,用循环伏安法电化学制备了聚邻苯二胺修饰膜电极,探讨了该聚合膜与Ni^2+的配合及其影响因素,关对配合后的膜电极进行了电化学研究。  相似文献   

9.
10.
利用亲核缩聚方法合成出带有氨基的磺化度可控的磺化聚芳醚酮砜共聚物(Am-SPAEKS),并在180℃下制备了C-Am-SPAEKS交联膜.红外和氢核磁图表明氨基已被引入到SPAEKS共聚物中,而且AmSPAEKS聚合物中的磺酸基团与氨基反应生成磺酰胺键而形成共价交联.通过对C-Am-SPAEKS膜性能测试发现,氨基与磺酸基团之间发生的共价交联反应使交联膜的致密性增加,从而使膜的甲醇渗透系数显著降低,膜的溶胀性、热稳定性和膜的保水能力都得到了提高.在120℃时C-Am-SPAEKS膜的质子传导率达到了0.0883 S/cm,而其甲醇渗透系数在25℃时为0.5×10-7cm2/s,明显低于SPAEKS膜的8.9×10-7cm2/s和Nafion膜的2×10-6cm2/s.实验结果表明,C-Am-SPAEKS膜能够满足质子交换膜燃料电池(PEMFC)的使用要求,有望在中高温和直接甲醇燃料电池中得以应用.  相似文献   

11.
The self-diffesion of water, ethanol and water-ethanol mixtures in chitosan (CS) membranes crosslinked byaqueous H_2SO_4 solution and uncrosslinked membrane was measured using pulsed-field gradient (PFG) nuclear magneticresonance (NMR) spectroscopy to obtain the partial solubilities and self-diffusion coefficients. An attempt was made toexplain the transport properties of water and ethanol through the CS membrane. It was concluded that there are two types ofchannel water and ethanol diffesate transfer. The water was localized in the hydrophilic ionic region formed by the ionizedgroups, and the ethanol was localized in the hydrophobic amorphous network of the polymer. There was a good agreementbetween the separation fastors estimated from PFG-NMR data and those obtained by pervaporation testing.  相似文献   

12.
简要介绍了利用光谱探针法研究膜模拟界面酸性的基本概念和基本原理,重点评述了这一方法的应用。  相似文献   

13.
无机膜反应器中乙苯脱氢反应的研究   总被引:4,自引:0,他引:4  
无机膜反应器中乙苯脱氢反应的研究钟丽,杨维慎,刘杰,丛铀,刘世河,林励吾(中国科学院大连化学物理研究所,大连116023)关键词膜反应器,乙苯,脱氢,微孔氧化铝膜将耐高温、耐腐蚀、结构较稳定的无机膜应用于高温催化反应,使反应与分离联为一体,已成为近年...  相似文献   

14.
Two kinds of polypeptides were tethered onto the surface of polypropylene microporous membrane (PPMM) through a ring opening polymerization of L-glutamate N-carboxyanhydride initiated by amino groups which were introduced by ammonia plasma and y-aminopropyl triethanoxysilane treatments. X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (FT-IR/ATR), scanning electron microscopy (SEM), together with water contact angle measurements were used to characterize the modified membranes. XPS analyses and FT-IR/ATR spectra demonstrated that polypeptides are actually grafted onto the membrane surface. The wettability of the membrane surface increases at first and then decreases with the increase in grafting degrees of polypeptide. Platelet adhesion and murine macrophage attachment experiments reveal an enhanced hemocompatibility for the polypeptide modified PPMMs. All these results give evidence that polypeptide grafting can simultaneously improve the hemocompatibility as well as reserve the hydrophobicity for the membrane, which will provide a potential approach to improve the performance of polypropylene hollow fiber microporous membrane used in artificial oxygenator.  相似文献   

15.
Heteropoly compounds (HPC), a kind of polyoxometallates, with their strong acidity and oxidative ability, are good homogeneous and heterogeneous catalysts in both acid-catalyzed and selective oxidation reactions, and have been widely used in petroleum and fine chemical industries. Owing to the diversity in their composition and structure, the catalytic properties of HPC can be altered in a wide range. Among them, the heteropolyanions with Keggin structure have been studied by far the most,especially on their applications in heterogeneous catalysis. However, since they are thermally unstable at high temperatures, their utilization in this field has been restricted. In the last ten years, inorganic membranes have been proved to be beneficial to heterogeneous catalytic processes for their high selectivity and good heat-conductivity. And the sol-gel method, one of the most common approaches to prepare inorganic membranes, is becoming mature. Here a sol-gel method to prepare a porous HPC membrane is reported. The catalytic performance of the membrane was tested through a model reaction, the selective oxidation of t-BuOH.  相似文献   

16.
于建 《高分子科学》2009,(3):387-392
Biopolymer chitosan was used to modify the mechanical properties of soluble eggshell membrane protein(SEP) films.The SEP/chitosan blend films were prepared by solution casting from 10%aqueous acetic acid.Tensile strength and elongation at break of the blend films increased with increasing amount of chitosan.Microphase separation was observed by field emission scanning electron microscopy,although interaction between the two components was revealed by FTIR.The biocompatibility of SEP/chitosan blend films ...  相似文献   

17.
以煤焦油为原料,通过在300℃空气氧化120min-480min和在430℃氮气热缩聚50min-270min,制备了一系列具有相近软化点的煤焦油沥青。原料煤焦油和改质沥青的化学结构通过了NMR、FT-IR、元素分析、软化点、族组成和偏光光学进行分析。在1.6MPa、480℃下将改质煤焦油沥青进行焦化,考察了焦收率和光学组织结构变化。结果表明空气氧化和氮气热缩聚可提高煤焦油沥青软化点、甲苯不溶物含量和焦收率,与氮气热缩聚沥青相比,相近软化点的空气氧化沥青具有较高的焦收率和O/C原子比。空气氧化煤焦油沥青成焦后各向异性光学结构单元尺寸随空气氧化时间增加而逐渐减小,而氮气热缩聚沥青成焦后均生成各向异性广域光学结构。  相似文献   

18.
乙丙三元橡胶磺酸钴离聚体膜的富氧性能研究   总被引:6,自引:0,他引:6  
通过磺化、中和反应制备了乙丙三元橡胶(EPDM)磺酸钴离聚体(Co(Ⅱ) S EPDM)膜并研究了其富氧性能.结果发现,该膜对分子氧具有促进输送作用,其原因被认为是在离聚体中可能形成了一种高分子钴络合物结构.这种络合物在其空位上能够与分子氧进行快速可逆的结合.ESR谱提供了钴氧结合的证据  相似文献   

19.
超临界二氧化碳体系中PVDF微孔膜的表面接枝改性   总被引:10,自引:0,他引:10  
超临界二氧化碳(SCCO2)是一种T〉31.1℃,P〉7.38MPa的二氧化碳流体,不仅具有类似于气体的粘度和类似于液体的密度,而且可以通过改变温度或压力控制SCCO2的密度及溶解性.SCCO2对有机小分子具有优良的溶解、扩散和渗透性能,化学惰性,无污染,易于分离,作为一种聚合反应介质,受到学术界日益增多重视.SCCO2极低的粘度使其具有良好的流动性和扩散渗透性能,零表面张力使其对聚合物具有良好的润湿和增塑性,这将促进引发剂和聚合单体向微孔膜的外表面及内表面扩散.利用温度和压力改变SCCO2的溶解性能调整单体在聚合物相和SCCO2相之间的分布,进而控制微孔膜内外表面的接枝程度.所以SCCO2接枝聚合反应对于聚合物膜的表面改性具有极其重要的意义.  相似文献   

20.
壳聚糖在水溶液中的辐射降解反应   总被引:1,自引:0,他引:1  
研究了壳聚糖在CH3COOH/NaCl缓冲溶液均相体系下的辐射降解反应,给出了H2O2、异丙醇、pH、样品初始分子量等因素对壳聚糖降解的影响,探讨了实验条件下溶液中不同自由基对壳聚糖降解的作用,并对辐照前后壳聚糖的结构进行了表征.结果表明,酸性条件下,壳聚糖的降解主要由.H和.OH自由基共同作用引起,加入H2O2或者通入N2O都能够略微提高.OH自由基浓度,对壳聚糖的降解有促进作用.加入异丙醇后,由于同时降低了.H和.OH自由基浓度,导致壳聚糖降解缓慢.当溶液的pH接近中性后,对壳聚糖的降解起主要作用的为.OH自由基,加入H2O2或者通入N2O都会增加.OH自由基的浓度,从而明显提高壳聚糖的降解速率.此外,研究发现低分子量的壳聚糖具有较快的降解速率.样品的UV、FTIR分析表明,辐照后除在壳聚糖分子链端生成羰基外,壳聚糖主链结构未见变化,脱乙酰度也没有显著改变,显示出辐射降解是一种有效的控制壳聚糖分子量方法.  相似文献   

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