Melt surface grafting of HDPE with mercaptoesters by thermolysis method

High‐density polyethylene (HDPE) was graft functionalized with two different mercaptoesters in an inert atmosphere at 160°C under different experimental conditions by thermolysis method. The order of functionalization, crosslinking, and C?C formation reactions were determined from the relative intensities of carbonyl stretching vibration and C? H bending vibrations. FTIR, DSC, and TGA analytical tools were used to characterize mercaptoester‐functionalized HDPE. A plausible reaction mechanism is proposed here to explain the experimental results obtained. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

一维链状有机锡化合物(PhCH2)3SnCl的合成、表征及晶体结构

利用苄基氯和锡反应，合成了一维链状有机锡化合物(PhCH2)3SnCl。通过元素分析、红外光谱和核磁共振氢谱对其结构进行了表征。用X-射线单晶衍射测定了该化合物的晶体和分子结构。锡原子呈畸变四面体构型。通过化合物分子间Sn…Cl作用，形成一维链状结构。     

Synthesis, characterization, crystal structure and theoretical calculations of an organotin(IV) complex with dithizone

The reaction of dimethyl tin dichloride with 1,5-diphenylthiocarbazone affords the complex [Sn(CH₃)₂(C₁₂H₁₁N₄S)Cl]. Its X-ray structure reveals a five-coordinated Sn atom in distorted trigonal bipyramidal geometry. The complex has been additionally characterized by IR and UV–Vis spectroscopy. Geometry optimization calculations support the experimental data.     

二苄基锡二对硝基苯甲酸酯的合成及表征

以苄基氯和锡粉为原料,n(Sn)∶n(BzCl) =1.0∶1.0的条件下,在乙苯中直接合成二苄基二氯化锡( Bz2 SnCl2),产率达80％以上;以二苄基二氯化锡、对硝基苯甲酸和三乙胺为原料,合成了二苄基锡二对硝基苯甲酸酯[ Bz2 Sn( O2 CPhNO2)2],当n(Bz2 SnCl2)∶n(HOCOPhNO...     

羧酸有机锡对PVC的热稳定作用——性能递变规律与机理

用烘箱变色法研究了羧酸二烷基锡对聚氯乙烯（PVC）的热稳定作用,结果表明,其热稳定性能随分子中与羧酸根羰基C原子相连基团的吸电子性的增强而提高;羧酸二烷基锡是通过其羧酸根羰基C原子和（或）二烷基锡离子作为亲电中心与PVC发生亲电反应而产生热稳定作用的;Frye和Horst所提出的传统热稳定剂作用机理不适用于羧酸二烷基锡。     

Hydrogenation of citral over Ru-Sn/C

Citral has been hydrogenated over Ru-Sn/C catalysts. The Ru-Sn/C system has been studied as a function of the Ru/Sn ratio. Under the conditions used the carbonyl group and the conjugated double bond are hydrogenated. No products obtained from the hydrogenation of the isolated double bond are formed. Addition of tin on the Ru/C decreases the number of Ru active sites on the surface with a corresponding increase in the specific catalytic activity. A higher selectivity (>80%) to geraniol + nerol is observed on the samples with the highest Sn/Ru ratio. The higher selectivity and higher specific activity are attributed to an activation of the CO bond by tin ions.     

On-line characterization by EXAFS of tin promoted platinum graphite catalysts in the aqueous phase

The structure of tin promoted graphite supported platinum catalysts has been studied with extended X-ray absorption fine structure spectroscopy (EXAFS). A newly developed EXAFS cell allows on-line characterization avoiding contact to ambient or drying. Hereto catalyst samples are transferred from a slurry reactor to the EXAFS cell forming a “bed” of catalyst particles in the EXAFS cell. The cell design was based on considerations concerning possible mass transport limitations while performing reactions in the liquid phase. The structures of the tin promoted platinum catalysts were investigated directly after preparation, drying, treatments with hydrogen (363 K) and oxygen (RT) in aqueous phase and a hydrogen gas treatment at 573 K at both the Pt L_III and the Sn K-edge. After preparation, under aqueous hydrogen, reduced platinum can be detected with three coordinations: Pt-Pt, Pt-C and Pt-Sn. Tin appears to be partly oxidic showing a Sn-O and a Sn-Pt coordination. A treatment with aqueous oxygen or exposure to ambient leads to oxidized platinum and tin. At the Pt L_III-edge only a Pt-Pt and Pt-O coordination for platinum are detected. At the Sn K-edge tin has only a Sn-O coordination. An aqueous treatment with hydrogen at 363 K reduces platinum showing, however, different coordination numbers for the Pt-Pt and Pt-Sn coordination. Tin only shows a Sn-O coordination. A treatment with hydrogen at 573 K reduces both the platinum and the tin. Platinum shows a Pt-Pt, Pt-C and Pt-Sn coordination. Tin shows a Sn-Pt and Sn-O coordination indicating tin deposition on the platinum, tin being bonded via oxygen to the graphite support. Reductive treatments in the aqueous phase appear to reduce platinum and only the tin deposited on the platinum. The effects of drying and consecutive reductive treatments could only be studied since the developed EXAFS cell allowed catalyst preparation and treatments avoiding contact to ambient.     

二元羧酸有机锡对聚氯乙烯的热稳定作用——性能递变规律与机理

用烘箱变色法测试了几种二元羧酸二烷基锡对聚氯乙烯（PVC）的热稳定作用。结果表明,其热稳定性能随分子中羧酸根羰基C原子正电性的增强而提高;如果分子中含有亲双烯结构单元,则其所稳定的PVC试片在最终黑化前呈现较轻的着色;二元羧酸二烷基锡是通过其带正电荷的羧酸根羰基C原子和（或）二烷基锡离子作为亲电中心与PVC发生亲电反应（简称亲电反应机理）对PVC产生热稳定作用;而如果分子中含有亲双烯结构单元,则同时以亲电反应和Diels-Alder反应机理发挥热稳定作用,但前者为主而后者为辅。     

Synthesis, Characterization and Antifertility Activity of New Unsymmetrical Macrocyclic Complexes of Tin(II)

A new series of unsymmetrical macrocyclic complexes of tin(ll) has been prepared by the template process using bis(3-oxo-2-butylidene)propane-1,3-diamine as precursor. This affords a method to synthesize these complexes with various ring sizes. The tetradentate macrocyclic precursor [N(4)mL] reacts with SnCl(2) and different diamines in a 1:1:1 molar ratio in refluxing methanol to give complexes of the type [Sn(N(4)mL)Cl(2)]. The ring expansion has been achieved by varying the diamine between the two diacetyl amino nitrogen atoms. The macrocyclic precursor and its metal complexes have been characterized on the basis of elemental analysis, molar conductance, molecular weight determinations, IR, (1)H NMR,(13)C NMR, (119)Sn NMR and electronic spectral studies. An octahedral geometry around the metal ion is suggested for these complexes. On the basis of molecular weights and conductivity measurements, their monomeric and non-electrolytic nature has been confirmed. The precursor and complexes have been screened in vitro against a number of pathogenic fungi and bacteria to assess their growth inhibiting potential. The testicular sperm density and testicular sperm morphology, sperm motility, density of cauda epididymal spermatozoa and fertility in mating trails and biochemicals parameters of reproductive organs have been examined and discussed.     

Supported RuB amorphous alloy mediated 1 atm hydrogenation of carbonyl compounds under ambient temperature

Tin promoted RuB amorphous alloy supported on SiO₂ was prepared by a novel reductant impregnation method for the hydrogenation of carbonyl compounds to the corresponding alcohol under atmospheric H₂ and ambient temperature. The as-prepared Ru–Sn–B/SiO₂ catalyst presented high activity for hydrogenation of carbonyl compounds even under atmospheric H₂. The TEM images showed that addition of tin improved the dispersion of RuB particles, and then significantly increased the conversion of carbonyl compounds. Based on the XPS spectra and catalytic performance, tin in Ru–Sn–B/SiO₂ catalyst was supposed to play a role of adsorbing and activating the CO bond of carbonyl group during the hydrogenation.     

Diimine copper(II) complexes as building blocks for microporous catalytic materials

New copper(II) complexes with tridentate diimine ligands, containing imidazolate-bridging groups, have been prepared as precursors of supramolecular-coordination-chemistry-based assemblies, designed to act as oxidation catalysts. These complexes were isolated as mono-, di- and polymeric or cyclic supramolecular species. In solution, solvent- and pH-dependent equilibria between the mono- and dinuclear complexes, or the mono- and the corresponding polymeric species were detected. Those species were characterized by different spectroscopic techniques (UV/Vis, IR, Raman and EPR), and the X-ray crystallographic structure was determined for one of them. The catalytic activity of the dinuclear and polymeric species in the oxidation of phenol substrates by molecular oxygen were verified, by monitoring the corresponding quinone formation. Cyclic hexa- or tetranuclear copper(II) species, exhibiting imidazolate-bridge groups between the copper centres, were observed to be better catalysts then the analogous dinuclear ones, mainly due the interaction of the substrate with the catalyst hydrophobic cavity. A modulation of the cavity size seems strongly affect the reactivity of these systems.     

Ion-Exchange Equilibrium of Ca2+, Mg2+, K+, Na+, and H+ Ions on Amberlite IR-120: Experimental Determination and Theoretical Prediction of the Ternary and Quaternary Equilibrium Data

Abstract

A study of the cation-exchange equilibria between Amberlite IR-120 resin and aqueous solutions of calcium, magnesium, potassium, and sodium chlorides and hydrochloric acid has been made. Experiments were carried out at 283, 303, and 323 K with solutions having total cation concentrations of approximately 0.1, 0.3, and 0.5 N. Experimental data for the ion-exchange equilibria of the ternary and quaternary systems are reported. These systems exhibit nonideal characteristics in both phases. The predictions have been based on the reaction equilibrium constants and correlations for the activity coefficients in both phases. A model which allows the prediction of multicomponent ion-exchange equilibria from binary data has been developed. Predictions of ternary and quaternary systems based solely on the binary data are in good agreement with the experimental results.     

Coupling agent studies: reaction of thiol-containing esters with aluminum

Double cantilever beam experiments performed by Joseph et al. showed increases in strain energy release rate and cohesive failure for mercaptoester-treated aluminum substrates as compared to untreated controls. This paper presents evaluation of the mercaptoester–aluminum reactivity as a first step toward assessing the effectiveness of incorporating the mercaptoester functionality into a polymeric coupling agent for an epoxy-aluminum bond system. Grazing-angle infrared spectroscopy and XPS of mercaptoester-treated solid aluminum substrates did not show evidence of a mercaptoester/aluminum reaction. The reaction was also attempted in solution where potential spatial limitations associated with the solid surface were eliminated. IR and NMR showed no evidence of reactivity between the mercaptoester and aluminum ions in solution. Theoretically, the Hard–Soft Acid–Base Theory, in conjunction with the Mison equation, does not support a mercaptoester–aluminum reaction. Thus incorporating a mercaptoester into a polymeric coupling agent for an epoxy–aluminum bond system would not result in chemical bonding. In addition, no significant reaction between thiols and aluminum in general, in the presence of water and moist air, is expected.     

双取代长链烷基酰胺的结构与萃取性能的研究

利用IR，1H－NMR和13C－NMR研究了不同结构酰胺与UO2^2 形成萃合物的结构，发现胺基对萃取剂的配位能力有较大的贡献，萃取剂羰基红外吸收峰和羰基碳化学位移的变化规律与碘化煤油中双取代酰胺萃取铀结构－性能规律相一致。     

Investigation of Steel/Epoxy Adhesion Durability Using Polymeric Coupling Agents. II. Factors Affecting Adhesion Durability

Ethylene mercaptoester (EME) copolymers containing 23-90 wt% mercaptoester units were employed separately as coupling agents in steel/epoxy peel adhesion systems. As coupling agent functionality is increased the initial adhesion strength of, the steel/EME/epoxy peel systems also increased, approaching a ten-fold improvement over controls for the EME 90 coupling agent. However, the degree of corrosion protection decreased significantly with increasing concentration of mercaptoester units. The best corrosion protection was obtained with the EME 23/epoxy resin system which protected the steel adherend for an average of 48 hours in 57°C water baths. Regardless of the coupling agent used, all of the peel specimens exhibited poor adhesion after 5-11 hours exposure to hot water. Information from hydrolysis stability, water absorption, locus of failure and internal stress analyses when pooled show that the observed adhesion loss is attributable to the effect of water on the epoxy resin used; failure occurred within the epoxy.     

Synthesis and crystal structures of mono-, bis- as well as tris-mercurated complexes with ferrocenylazines

The mono-(cyclomercurated) complex (2) and bis-(cyclomercurated) complexes (3) as well as the first example of a tris-mercurated ferrocenylimine (4) have been conveniently prepared from the reaction of ferrocenylazines (1) with Hg(OAc)₂ and subsequent treatment with LiCl. All the new compounds were characterized by elemental analysis, ¹H NMR and IR spectra. X-ray single crystal analysis confirms that complex 2 exists as a tetramer in the crystal due to intermolecular bridged Cl–Hg bonds and weak intermolecular N–Hg coordination. While 3b and 4 have a one-dimensional chain structure formed by intermolecular bridged Cl–Hg bonds and CH(Cp)⋯Cl hydrogen bonds.     

Synthesis,characterization and catalytic activity of a new sandwich-type tungstophosphate functionalized by carboxyethyltin

Reaction of the trivacant Keggin-type tungstophosphate (A-α-Na₉PW₉O₃₄⋅ 7H₂O, abbreviated as {PW₉}) with estertin (Cl₃Sn(CH₂)₂COOCH₃) in an acetate buffer solution leads to the formation of a new sandwich-type tungstophosphate functionalized by carboxyethyltin, Na₃K₈[K₃{Sn(CH₂)₂COO}₂(A-α-PW₉O₃₄)₂]·18H₂O (1). The title compound was characterized by single crystal X-ray diffraction, elemental analysis, IR, TG, PXRD, ¹³C, ³¹P and ¹¹⁹Sn NMR. Structural analysis reveals that the basic skeletal structure of 1 is made up of two [Sn(CH₂)₂COO]^2 + groups and three K⁺ ions sandwiched by two A-α-[PW₉O₃₄]^9 − building blocks, which shows the original estertin precursors hydrolyzed into carboxyethyltin. The catalytic activity of 1 has been investigated.     

Mullite-type EMBO4: synthesis,structural, optical,and vibrational properties of rare tin(II) borates with M = Al and Ga

Metal tin-(II)-borates are rarely studied mainly due to the susceptibility of either oxidation into tin(IV) or disproportionation into elemental tin(0) and tin(IV). We report mullite-type SnAlBO₄ and SnGaBO₄ ceramics produced by conventional solid-state synthesis in sealed quartz tubes at low pressure of 10^–7 MPa. Both compounds are isostructural to PbAlBO₄ as confirmed by Rietveld refinements of powder X-ray data. The crystal structures are highly influenced by the stereochemical activity of the 5s² lone electron pair of the Sn²⁺ cation measured by the Wang–Liebau eccentricity parameter. To further consolidate the structural features ¹¹⁹Sn Mössbauer, solid state NMR, Raman, IR and UV/vis spectroscopic measurements are performed. The ¹¹⁹Sn Mössbauer isomer shifts and the quadrupole splitting values confirm the SnO₄ coordination and Sn(II) valence states. Solid state ¹¹B, ²⁷Al and ¹¹⁹Sn NMR spectra provided insights into the local crystal-chemical environment. The vibrational properties are discussed from group theoretical analysis to mode assignments. SnAlBO₄ and SnGaBO₄, respectively, possess an electronic band gap of 3.73(9) and 3.21(4) eV calculated from the diffuse reflectance UV/Vis spectra.     

Preparation and characterization of novel chitosan‐based mixed matrix membranes resistant in alkaline media

In this work, mixed matrix membranes (MMMs) based on chitosan (CS) and different fillers (room temperature ionic liquid [emim][OAc] (IL), metallic Sn powder, layered titanosilicate AM‐4 and layered stannosilicate UZAR‐S3) were prepared by solution casting. The room temperature electrical conductivity and electrochemical response in strong alkaline medium were measured by electrochemical impedance spectroscopy and cyclic voltammetry (CV). The ionic conductivity of pure CS membranes was enhanced, from 0.070 to 0.126 mS cm^?1, for the pristine CS and Sn/CS membranes, respectively, as a function of the hydrophilic nature of the membrane and the coordination state of Sn. This hydrophilic and charge nature was corroborated by water uptake measurements, where only the introduction of IL in the CS membrane led to a water uptake of 3.96 wt %, 20 or 30 times lower than the other membranes. Good thermal and chemical stability in alkaline media were observed by thermogravimetric analyses and X‐ray photoelectron spectroscopy analyses, respectively, and good interaction between CS and the fillers observed by X‐ray diffraction, scanning electron microscopy and CV. Thus, thin CS‐based MMMs (40–139 µm), resistant in high alkaline media, show higher conductivity than pure CS membranes, especially those fillers containing tin, and although the electrochemical performance is lower than commercially available anion‐exchange membranes they have potential in pervaporation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42240.     

三苯基锡(Ⅳ)四氢吡咯荒酸酯的合成、表征、性质及晶体结构

用三苯基氯化锡和四氢吡咯荒酸钠反应 ,合成了三苯基锡 ( )四氢吡咯荒酸酯。通过元素分析、红外光谱和氢核磁共振谱对其结构进行了表征。用 X-射线单晶衍射测定了该化合物的晶体结构。结果表明 ,化合物中锡原子呈五配位畸变三角双锥构型