有机硅油改性水性酚醛的制备及其性能

以烯丙基聚氧化乙烯醚(PEO)和烯丙基缩水甘油醚(AGE)为原料,进行硅氢加成反应对有机硅油进行接枝改性,使其在水中具有分散性并引入了具有反应活性的环氧基团。使用红外光谱(FT-IR)和核磁共振氢谱(¹H-NMR)表征其结构,用示差扫描量热分析(DSC)和热重分析(TGA)表征改性硅油与水性酚醛树脂共混的稳定性和耐热性能。将有机硅改性酚醛树脂应用于机油滤纸,用扫描电镜(SEM)分析其微观形貌并探究其力学性能、耐油和耐高温性能。结果表明,PEO与AGE的摩尔比为3:1时共接枝有机硅在水中具有良好的分散性能,以5%的质量比与水性酚醛树脂共混复配后形成三维网络结构,具有良好的共混稳定性。通过浸渍增强的机油滤纸,其力学性能均有较大的提高。经过高温机油浸泡后的滤纸保持较高的力学性能,其挺度保持率、耐破度保持率和抗张强度保持率分别为55%、63%和87%。     

聚醚改性氟硅表面活性剂的合成与溶液性质研究

通过阴离子开环聚合和硅氢加成反应得到聚醚改性氟硅表面活性剂和聚醚改性硅氧烷表面活性剂;并用核磁和红外来表征其结构。对聚醚改性有机硅表面活性剂和氟硅氧烷表面活性剂以及全氟表面活性剂进行溶液性质的研究发现：全氟表面活性剂的最小表面张力最低,聚醚改性氟硅表面活性剂的最小表面张力比聚醚改性的硅氧烷要高;对于相同的亲水链段和疏水链段聚醚改性的氟硅氧烷,其临界胶束浓度（CMC）比聚醚改性硅氧烷小;聚醚改性硅氧烷亲水链段的长度增加,CMC减少;而聚醚改性氟硅氧烷的疏水链段长度增加,CMC增加。     

Hydrosilylation of Aldehydes and Ketones Catalyzed by Half‐Sandwich Manganese(I) N‐Heterocyclic Carbene Complexes

Easily available manganese(I) N‐heterocyclic carbene (NHC) complexes, Cp(CO)₂Mn(NHC), obtained in one step from industrially produced cymantrene, were evaluated as pre‐catalysts in the hydrosilylation of carbonyl compounds under UV irradiation. Complexes with NHC ligands incorporating at least one mesityl group led to the most active and selective catalytic systems. A variety of aldehydes (13 examples) and ketones (11 examples) were efficiently reduced under mild conditions [Cp(CO)₂Mn(IMes) (1 mol%), Ph₂SiH₂ (1.5 equiv.), hν (350 nm), toluene, 25 °C, 1–24 h] with good functional group tolerance.

     

Regioselective catalyzed modification of poly(methylhydro)siloxane using RuRh and RuPt bimetallic dendrimer‐encapsulated nanoparticles

RuRh and RuPt bimetallic dendrimer‐encapsulated nanoparticles (DENs) were successfully prepared by a two‐step process involving co‐complexation, using ruthenium and rhodium or ruthenium and platinum complex ions with partially quaternized fifth‐generation poly(amidoamine) (G5‐Q), and then coreduction with NaBH₄. UV–vis, transmission electron microscope, and laser scattering analyses were used to characterize the bimetallic alloy DENs. The regioselective synthesis of multifunctional hybrid poly(methylhydro)siloxane was achieved by the RuRh and RuPt alloy nanoparticle catalysts. The experimental results showed that the RuRh and RuPt bimetallic DENs presented higher catalytic activity than physical mixtures of their monometallic DENs, respectively. This should be due to synergistic electronic effect of RuRh and RuPt alloy catalysts. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

YAG：Ce,Ln体系中Ce~（3＋）的荧光寿命的研究

采用高温固相法合成了一系列的（Y0.95Ln0.01Ce0.04）3Al5O12（简称YAG∶Ce,Ln）,系统地研究了此体系中Ln3＋对Ce3＋的荧光寿命的影响。结果表明,荧光寿命数值能够较好地说明双掺杂晶体中除Ce3＋以外的其它三价稀土离子（Ln3＋）对Ce3＋的发光强度的增强或者猝灭现象。     

正辛基三乙氧基硅烷的合成

在催化剂存在下,利用正辛烯与三乙氧基氢硅烷进行硅氢加成反应制备正辛基三乙氧基硅烷.采用气相色谱-质谱(GC-MS)法对正辛基三乙氧基硅烷的结构进行了表征,考察了滴加方式、原料配比、反应温度以及反应时间对反应的影响.较佳的反应条件为:正辛烯和三乙氧基氢硅烷以1.05:1的量之比投料,采用滴加三乙氧基氢硅烷的方式反应,反应...     

可交联亲水性聚硅氧烷的合成与表征

以丙烯酸聚乙二醇酯、甲基丙烯酸缩水甘油酯和含氢硅油为原料在甲苯溶剂中进行硅氢加成反应,红外光谱和核磁共振谱对产物分析表明,合成了一种新型的、可交联的、亲水性有机硅材料.探讨了反应时间、反应温度、反应物的摩尔比对含氢硅油活性氢转化率的影响规律.实验表明,当催化剂用量为反应物质量分数的0.004%时,含氢硅油活性氢(PHMS)、丙烯酸聚乙二醇酯(PEGA)和甲基丙烯酸缩水甘油酯(GMA)的摩尔比为1:1.125:0.1,在85℃下反应8h,含氢硅油活性氢的转化率达到82%.     

Asymmetric Hydrosilylation of Prochiral Ketones Catalyzed by Nanocrystalline Copper(II) Oxide

Asymmetric hydrosilylation of aryl alkyl ketones to afford chiral secondary alcohols with good yields and excellent enantioselectivity is realized by using nanocrystalline copper(II) oxide and BINAP in the presence of organosilanes as the stoichiometric reducing agents.