双环笼状四配位硅的合成及其结构表征

研究了以SiO₂为原料低温合成高反应活性的五配位硅酸酯, 并与1-氧代-1-磷杂-2,6,7-三氧杂双环[2.2.2]-4-氯甲基辛烷反应合成出具有对称结构的双环笼状四配位硅, 通过红外光谱、¹³C和²⁹Si固体核磁共振、质谱等测试手段确定了其结构. 热分析结果表明, 双环笼状四配位硅在700 ℃的失重仅为19.98%, 且炭层呈密实片层状, 说明目标产物具有优异的热稳定性和成炭性质.     

笼状双环磷酸酯类化合物的合成与生物活性研究

近年来,科学家们相继合成出高度对称结构的双环磷酸酯笼状化合物,并研究了它们的生物活性,这类化合物具有良好的杀虫抗菌活性,且有独特的活性机理,在医药、农药、纤维、树脂及石油工业中已得到了广泛应用,本文采用季戊四醇和苯乙腈为起始原料,以下列反应步骤设计合成了8个新型笼状双环磷酸酯衍生物I,[1′-硫(氧)代-2′,6′,7′-三三氧杂-1′-磷杂双环(2,2,2)辛烷基-4′-甲基]-4-烷基-4-苯基-4-氰基丁酸酯:     

六聚笼型倍半硅氧烷的合成及解离研究

采用环己基三氯硅烷为反应物,乙腈为溶剂,通过水解反应合成出纯净的环己基六聚笼型倍半硅氧烷T6(化合物1),通过FT-IR、29SiNMR、XRD、MS对其结构、分子量、晶型等进行了全面的表征。并成功将其解离为四硅醇物质(化合物2),为合成封闭双官能化的八聚笼型倍半硅氧烷奠定了基础。     

双环笼状磷酸酯衍生物的研究Ⅵ:4-取代-2,6,7-三氧杂-1-磷杂双环[2.2.2]辛烷的反应研究

双环笼状亚磷酸酯类衍生物由于其笼状结构所引起的张力及高位阻性,使得它同一般直链亚磷酸酯类化合物相比,在亲核取代反应性等方面有着明显的不同.本文用化合物1分别同SO_2Cl_2,Cl_2,Br_2,PCl_5等反应,结果表明,1均发生了类Arbuzov反应,生成具有相同立体构型的开环产物.本文还对化合物2的磷酰化反应进行了研究,发现在这类高位阻性的双环笼状亚磷酸酯衍生物的磷酰化反应中,DMAP是一个较有效的催化剂.     

八乙烯基笼型倍半硅氧烷环氧化产物的合成与表征

以八乙烯基笼型倍半硅氧烷(OVPOSS)为原料,3-间氯过氧苯甲酸(m-CPBA)为氧化剂,制得含环氧基团的乙烯基笼型倍半硅氧烷,利用红外光谱及核磁光谱对其结构进行了表征,并研究了八乙烯基笼型倍半硅氧烷环氧化产物在三氯甲烷中的紫外光谱行为。     

对苯二酚-二(4-氧代-4-磷杂-3,5,8-三氧杂双环[2.2.2]辛基)甲酸酯的合成及表征

自1960年Verkade 等[1 ]首次合成了结构新颖的双环笼状磷酸酯以来,由于其高度对称的结构而引起人们的极大兴趣,具有生物活性的衍生物不断见诸报道[2～3 ].由于该化合物具备丰富的炭源(季戊四醇) 和酸源(磷酸),其衍生物逐渐成为无卤膨胀阻燃剂研究的热点之一.李昕等[4-5]以PEPA为中间体,合成了分子中同时具有三个笼状磷酸酯结构的化合物的三聚物(Trimer),结构对称性好,磷含量高,热稳定性和成炭性比较好.杨兴钰等[6]以PEPA为中间体,合成了8个双环笼状磷酸酯酰胺类化合物,该类化合物集酸源、炭源和气源于一体,应用于环氧树脂材料中具有良好的阻燃性.目前含有芳环结构的PEPA衍生物的合成鲜有报道.本研究课题以季戊四醇、三氯氧磷、浓硝酸、二氯亚砜和对苯二酚等为原料,合成了一种具有芳环结构、含磷量高、耐热性好、无卤等特点的PEPA衍生物对苯二酚-二(4-氧代-4-磷杂-3,5,8-三氧杂双环[2 2 2]辛基)甲酸酯.合成路线如下:1 实验部分1.     

二茂铁取代的笼型八聚(二甲基硅氧基)倍半硅氧烷的合成与表征

在Karstedt催化剂的催化作用下,通过把合成的笼型八聚(二甲基硅氧基)倍半硅氧烷与乙烯基二茂铁进行氧化硅烷化反应,合成了二茂铁取代的笼型八聚(二甲基硅氧基)倍半硅氧烷,产物经红外光谱、核磁共振氢谱与硅谱等进行了表征.     

八苯基笼型倍半硅氧烷的官能化及其在高分子纳米复合材料中的应用

笼型倍半硅氧烷（POSS）是具有独特分子结构的有机硅化合物,无机硅氧骨架核心为其提供良好的硬度和热稳定性,外围有机基团可增强与聚合物基体间的相容性,以它为前驱体可以制备分子级分散的有机／无机纳米高分子杂化材料。近年来,全芳香结构的八苯基笼型倍半硅氧烷因其高的耐热性和官能化方法的多样性尤其得到关注。本文重点综述了八苯基笼...     

四配位硅单体及其共聚物的制备和结构表征

研究了直接从无定形二氧化硅出发, 与乙二醇、氢氧化钾反应, 生成高反应活性的五配位硅钾化合物, 并以此为原料与含活泼氯的3-氯丙烯反应制备出含双键官能团的四配位硅单体. 讨论了合成单体的条件如温度、反应时间、反应物浓度、溶液pH值及溶剂等因素的影响. 然后以该四配位硅单体与甲基丙烯酸甲酯(MMA)在偶氮二异丁腈(AIBN)作引发剂下进行自由基聚合得到支链含硅共聚物. 并借助于红外光谱(IR)、核磁共振(¹³C和¹H, ²⁹Si)、能谱元素分析对合成的单体进行了结构表征; 用红外光谱(IR)、热失重谱(TG)、差示扫描量热谱(DSC)、凝胶渗透色谱法(GPC)等现代测试手段对支链含硅共聚物进行了结构表征及热性能分析. IR表明四配位硅单体在1646 cm^－1处是C＝C的伸缩振动吸收峰, 在共聚物中此峰消失; TG表明共聚物在249.6 ℃才开始失重, 552 ℃有机部分失重完毕; GPC分析表明共聚物的数均分子量为8.7万.     

1-硫代-1-磷杂-2,6,7-三氧杂双环[2.2.2]辛烷基-4-亚甲基硫醚及其亚砜的合成

本文通过Williamson反应,合成了9个双环笼状硫代磷酸酯的硫醚衍生物3a～i。以3b,3c为例研究了硫醚衍生物的还原性,并合成相应的亚砜化合物4b,4c。讨论了亚砜化合物的立体化学。     

Synthesis, application and flame retardancy mechanism of a novel flame retardant containing silicon and caged bicyclic phosphate for polyamide 6

A novel flame retardant containing silicon and caged bicyclic phosphate groups, tri(2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-1-oxo-4-hydroxymethyl) phenylsilane (TPPSi) was successfully synthesized. The chemical structure of TPPSi was characterized by FTIR, ¹H NMR and ³¹P NMR. The application of TPPSi (25 wt%) as a flame retardant in polyamide 6 (PA6) not only gains satisfied flame retardancy and smoke suppression, but also retains the high toughness and inherent appearance of pure PA6. The influence of TPPSi on the decomposition pathway of PA6 was discussed based on TG-FTIR and FTIR analysis. The interaction between TPPSi and PA6 at high temperature alters the decomposition pathway of PA6 resulting in the formation of the residue containing phosphorus and silicon. The heat and smoke release behaviors at different external heat fluxes were measured by cone calorimeter, and the fire residue was analyzed by SEM-EDX. The condensed phase action resulting from the barrier effect of residue is proposed to be the major flame retardancy mechanism of TPPSi in PA6, with the fuel reduction action as the minor.     

Synthesis and application of amino resinous intumescent flame retardants

A kind of amino resinous intumescent flame retardants (IFR) was firstly synthesized, and the structure of the main composition was determined to be a caged bicyclic macromolecule containing phosphorus. The 30% weight of IFR was added into the flexible polyurethane foam (FPUF) to get retardant FPUF which has 26.5% of the limiting oxygen index. The date of CONE show that the heat release, smoke and gas of the flame retardant FPUF are much decreased and the activation energy decreases by 54 kJ·mol⁻¹. It shows that the IFR can catalyze decomposition and carbonization of FPUF. __________ Translated from Transactions of Beijing Institute of Technology, 2008, 28(5) (in Chinese)     

机械化学法原位合成硅/锡二元储锂母体复合负极材料的研究

以高活性、低熔点金属锂为还原剂,在惰性气氛保护下分别将一氧化硅和氧化亚锡还原为单质硅和锡。通过调节球磨参数并加入适量助磨剂有效抑制因金属锂熔化导致的物料结块现象,得到将纳米硅、锡颗粒均匀分散在含锂化合物基体中的二元储锂母体复合材料。通过该方法得到的复合材料中硅、锡颗粒粒径明显小于商品化的纳米硅和纳米锡,不仅能最大限度降低硅、锡颗粒的体积效应,避免纳米粉体的分散工序,且能大大降低材料的制备成本。交流阻抗和充放电循环测试显示,金属锡作为另一种储锂母体既能为复合材料提供部分可逆容量,也能有效降低活性物质颗粒之间     

具有碱催化活性的有序氮氧化硅MCM-41介孔分子筛的制备与性能研究

以介孔氧化硅MCM-41为氮化前驱体, 以纯的氨气为氮源, 通过调节氮化工艺参数, 制备出了氮含量高达23.01 wt%、比表面积高达665.4 m²•g^－1、平均孔径为2.5 nm的氮氧化硅有序介孔分子筛材料. 采用CNH元素分析、N₂吸附- 脱附分析、小角XRD、高分辨透射电镜(HRTEM)、红外光谱以及²⁹Si 固体核磁共振谱(MAS NMR)等技术对材料的结构进行系统的研究. 并且通过苯甲醛和丙二腈的缩合反应研究了该类材料的碱催化活性. 研究表明, 在30 ℃反应3 h后苯甲醛的转化率达到99.9%.     

Formation of cage phosphonate via hydrolysis of 2-(5-methyl-2-phenyl-2<Emphasis Type="Italic">H</Emphasis>-1,2,3-diazaphosphol-4-yl)-1,5-dioxo-4-trifluoromethyl-4-ethoxycarbonylbenzo[<Emphasis Type="Italic">f</Emphasis>]-1,3,2-dioxaphosphepine

A new approach to obtaining of caged bicyclic phosphonate, 4-hydroxy-3-trifluoromethyl-3-ethoxycarbonyl-8-(1-phenylhydrazonoethyl)-5,6-benzo-2,7,1-dioxaphosphabicyclo[3.2.1^1.5]octane, based on hydrolysis of 2,5-dioxobenzo[f]1,3,2-dioxaphosphepine derivative bearing 5-methyl-2-phenyl-2H-1,2,3-diazaphosphol-4-yl substituent at the phosphorus was developed. The hydrolysis process includes elimination of P(II) atom and intramolecular cyclization involving endocyclic carbonyl group of the phosphepine. Structure of the caged phosphonate was established by NMR and XRD methods.     

Immobilization of thiabendazole-specific monoclonal antibodies to silicon substrates via aqueous silanization

Monoclonal antibodies specific for thiabendazole were immobilized to silicon, silicon dioxide, stoichiometric silicon nitride, and silicon-rich silicon nitride surfaces. This work provides the foundation for the development of a homogeneous sensor system for rapid detection and quantification of thiabendazole residues in produce and animal tissue. Immobilization was performed via aqueous silanization of the substrate followed sequentially by treatment with glutaraldehyde and contact with antibody solution in the presence of detergent. Surfaces were challenged with thiabendazole-horseradish peroxidase conjugate in an ELISA format to estimate immobilized antibody load. A stable and reproducible surface loading of 2 x 10¹¹ antibodies/cm² was obtained only after surfaces received postimmobilization treatments to remove nonspecifically adsorbed antibody. No difference in surface loading was noted when using 30% hydrogen peroxide rather than nitric acid for silanol activation. Little difference was noted among the antibody loadings achieved on the various silicon substrates. Bound antigen-enzyme conjugate was eluted with 0.1N acetic acid and reproducible surface activity was measured for up to four consecutive antigen challenges. Immobilized antibody surfaces were stabilized with 2% sucrose, dehydrated at 37‡C and stored in vacuum or stored at 4‡C in phosphate buffered saline containing 0.01% sodium azide without significant loss of activity.     

高碳铬铁中磷,硅,锰的电感耦合等离子体原子发射光谱测定方法的研究

采用过氧化钠在石墨坩埚中熔融分解样品，硝酸酸化后直接用ＩＣＰ测定。磷，硅，锰的测定范围分别为０．００５％－０．０７５％，０．３０％－６．００％，０．０３％－２．００％，相对标准偏差ＲＳＤ≤６．０％。     

Thermal degradation and flame retardancy of epoxy resins containing intumescent flame retardant

Pentaerythritol diphosphonate melamine-urea-formaldehyde resin salt, a novel cheap macromolecular intumescent flame retardants (IFR), was synthesized, and its structure was a caged bicyclic macromolecule containing phosphorus characterized by IR. Epoxy resins (EP) were modified with IFR to get the flame retardant EP, whose flammability and burning behavior were characterized by UL 94 and limiting oxygen index (LOI). 25 mass% of IFR were doped into EP to get 27.2 of LOI and UL 94 V-0. The thermal properties of epoxy resins containing IFR were investigated with thermogravimetry (TG) and differential thermogravimetry (DTG). Activation energy for the decomposition of samples was obtained using Kissinger equation. The resultant data show that for EP containing IFR, compared with EP, IFR decreased mass loss, thermal stability and R _max, increased the char yield. The activation energy for the decomposition of EP is 230.4 kJ mol⁻¹ while it becomes 193.8 kJ mol⁻¹ for EP containing IFR, decreased by 36.6 kJ mol⁻¹, which shows that IFR can catalyze decomposition and carbonization of EP.     

Synthesis of Poly(silyne-co-hydridocarbyne) for Silicon Carbide Production

Pre-ceramic polymers have previously been shown to be polymeric precursors to silicon carbide, diamond and diamond-like carbon. Here, we report the synthesis of a pre-ceramic polymer, poly(silyne-co-hydridocarbyne), which was electrochemically synthesized from one monomer containing both silicon and carbon in its structure. The polymer is soluble in common solvents such as CHCl₃, CH₂Cl₂ and THF. Since the polymer contains both silyne and carbyne on its backbone, it can be easily converted to silicon carbide upon heating under an ambient inert atmosphere, or to SiO₂ under ambient air atmosphere. Poly(silyne-co-hydridocarbyne) was characterized with UV/Vis spectroscopy, FTIR, ¹H-NMR, GPC and Raman spectroscopy. Conversion of the polymer to SiC ceramic was accomplished by heating at 1000 and 750°C under an argon atmosphere and characterized with optical microscopy, SEM, X-Ray and Raman spectroscopies.