四正丁基铵高聚碘的合成及其杀菌性能研究

以碘和四正丁基碘化铵为原料,研究了四正丁基铵高聚碘的合成,考察了不同原料配比对产物聚合度的影响。采用Raman和TG分别表征了产物的结构和热稳定性;采用抑菌环法、悬液定量法和振荡烧瓶法测定了产物的杀菌性能,并讨论了其杀菌机理。结果表明,通过改变反应物配比只能生成n-Bu4NI3.0、n-Bu4NI5.0和n-Bu4NI5.43种四正丁基铵高聚碘,其中n-Bu4NI3.0只含有I-3结构,n-Bu4NI5.0只含有I-5结构,而n-Bu4NI5.4是含有I-3、I-5和I-73种结构的混合物。在3种四正丁基铵高聚碘中,n-Bu4NI3.0的热稳定性最好。四正丁基铵高聚碘具有优良的杀菌性能,其杀菌作用分两部分:微量溶于水的高聚碘产生的杀菌作用与高聚碘固体颗粒表面的杀菌作用。     

不同聚合度四乙基高聚碘的合成、结构分析及其杀菌活性

以四乙基碘化铵、碘单质为原料,在乙醇溶剂中合成了不同聚合度的四乙基高聚碘。通过拉曼光谱(Raman)、热重分析(TG)、紫外可见光谱(UV/Vis)对四乙基高聚碘结构、热稳定性及其在溶液中存在的形式进行了研究,采用悬液定量法,考察了四乙基高聚碘水溶液的杀菌效果。研究结果表明:四乙基高聚碘存在形式为Et4NI3、Et4NI5、Et4NI7及其混合态,其最稳定态为Et4NI3,最高聚合态为Et4NI7;分解温度均大于100℃,具有很好的稳定性;在乙醇溶液中的存在形式主要是:I-3、I-、I2;在水溶液中的存在形式主要是I-、I2;四乙基高聚碘在水溶液中的杀菌效果主要是由其溶出的碘单质浓度所决定的,与其固态高聚碘的聚合度关系不大。     

相对分子质量对双酚AF硫化氟橡胶胶料性能的影响

运用降级链转移生产氟橡胶已逾25年，这是受控自由基聚合用于工业最成功的范例。此过程是在二碘化全氟烃链转移剂存在下氟烯烃聚合，碘原子从原反应剂转入氟橡胶链端。但是由于新的碘一碳键键能几乎与在原全氟烃里的相同，所以碘封端的聚合物链本身即可作为链转移剂。     

异十异戊二烯醇的合成

以茄尼醇为原料,吡啶为催化剂,在石油醚中与PBr3反应得到茄尼基溴,收率90%;然后将其溶于石油醚中与乙酰乙酸甲酯反应,采用无水碳酸钾作为碱,碘化四正丁基铵(TBAI)为相转移催化剂,得到的中间产物在碱性条件下酮式分解得到茄尼基丙酮,收率90%;再在氮气保护下与溴乙烯镁格氏试剂反应,得到标题化合物,收率75%。通过熔点I、R、1HNMR验证了化合物的结构,与文献报道一致。     

微波辅助下5-碘尿嘧啶衍生物的快速合成

在微波辐射下,I2在稀硝酸水溶液中快速在尿嘧啶5位发生碘化反应,以较高产率得到了9个5-碘嘧啶衍生物(75%~90%)。产物结构经1HNMR和13CNMR确证。     

大位阻富电子金刚烷基有机膦配体的合成

以金刚烷为原料,利用傅克酰基化反应得到双(1-金刚烷基)膦酰氯,再用氢化铝锂还原后得到二-1-金刚烷膦,然后与1-碘丁烷成盐得到对空气稳定的正丁基二(1-金刚烷基)膦碘化盐,最后用氢氧化钠释放得到最终产品正丁基二(1-金刚烷基)膦,总收率达72%,产品结构经核磁氢谱、碳谱得以证实,气相色谱检测纯度达98%。     

连载《橡胶科学和技术》——第六章 未硫化胶料的流变行为(四)

无填料胶料(纯胶料)的分子结构与流变性能 A.结晶转变与应力诱导结晶高聚物结构最重要的特点之一,是高聚物主链微观结构的均一性。高聚物中所有的或大部分结构单元的特性相同,在这个意义上说,由于主链结构非常规整,所以会导致结晶的出现。这里所说的结构单元的等同性,不仅包括化学特性和原子排列顺序相同,而且还包括几     

碘催化合成对-正丁基苯胺的正交实验研究

以碘作催化剂、以正丁醇与苯胺为原料在高压反应釜内催化合成对-正丁基苯胺,用GC-MS和气相色谱对产物进行定性和定量分析。通过正交实验确定最佳反应条件如下:反应温度300℃、反应时间10h、碘量0.910g(占苯胺质量的10‰)、搅拌速度450r·min-1,在此条件下,对-正丁基苯胺收率为49.84%,并在以负载型催化剂I2/Al2O3代替单质碘时达到55.51%。     

光纤涂料

正201602051含有非辐射固化型丙烯酸硬-软嵌段共聚物的光纤涂料:WO2015 147 961[国际专利申请]/美国:Corning Incorporated(Bookbinder,Dana Craig等).-2015.10.01.-35页.-US201 461 925 795(2014.01.10)一种光纤涂料组合物含有一种辐射固化组分、光引发剂、一种非辐射固化丙烯酸共聚物等。其中,非辐射固化丙烯酸共聚物不含氨基甲酸酯基团和脲基团,具有第一种丙烯酸重复结构单元和第二种丙烯酸重复结构单元,结构单元的玻璃化温度分别为50℃和0℃。实例中的丙烯酸链段为甲基丙烯酸甲酯和丙烯酸丁     

耐高温聚合物的结构和热稳定性的关系

按照聚合物结构的特性大体上可将现有耐高温聚合物分为五大类: 1.碳链聚合物其中包括芳香结构单元的碳氢聚合物;此类聚合物由单键C—C键相链,基本结构单元为双酚、三酚、萘、蒽和萘并萘等,此类聚合物有聚苯撑,聚对二甲苯和全氟乙烯的聚合物等。 2.杂链聚合物 以杂原子或基团相连结的芳环线型链为基本结构单元,如聚苯     

Non-classical hydrogen bond (CH∙∙∙I) directed self-assembly formation of a novel 1D supramolecular polymer,based on a copper complex [Cu{(CH3)2SO}6]I4

The structure of the new complex with molecular formula [Cu{(CH₃)₂SO}₆]I₄, has been determined. The compound comprises discrete [Cu{(CH₃)₂SO}₆]^2 + units connected through a self-assembly process with a linear arrangement of polyiodide I_2n + 2^2 −, driven by non-classical hydrogen bonds CH∙∙∙I. The polyiodide chain presents a neutral I₂ molecule weakly coordinated with two iodide anions. The linear, uncoordinated, centrosymmetric polyiodide anion represents a rare example of a tetraiodide.     

Synthesis and physical properties of Curdlan branched Ester derivatives

Curdlan is a high-molecular-weight linear β-1,3-glucan synthesized by microorganisms. A series of curdlan branched esters with a degree of substitution of three were synthesized and their physical properties and structures were compared with those of curdlan linear esters. Thermal degradation temperatures of all the curdlan branched esters were ca. 360 °C; almost the same as those of curdlan linear esters. The curdlan branched esters had melting temperatures (T _m ) higher than those of the corresponding curdlan linear ester with the same side-chain carbon number. In particular, comparing T _m of curdlan propionate, curdlan isobutyrate, and curdlan pivalate, the latter two had high T _m of over 335 °C, suggesting that the degree of branching of the side chain affects the stability of molecular chains with helix structure in their crystals. Highly transparent films were prepared from the curdlan branched esters. These films exhibited higher Young’s modulus and tensile strength compared with those of films composed of the linear equivalents with the same side-chain carbon numbers. These results indicate that curdlan branched esters are promising thermoplastics with favorable thermal and mechanical properties because of the closer packing structure of their molecular chains than that of the corresponding curdlan linear esters.     

Structure of Calcium Silicate Hydrates Formed in Alkaline-Activated Slag: Influence of the Type of Alkaline Activator

The influence of the alkaline activator (NaOH, waterglass, or Na₂CO₃) on the structure of the hydrated calcium silicate formed in alkali-activated slag (AAS) cement pastes has been investigated by FTIR, ²⁹Si and ²⁷Al magic-angle scattering nuclear magnetic resonance, and TEM/EDX techniques. In all cases, the main product formed after 7 d of activation, with activators giving an Na₂O concentration of 4%, is a semicrystalline calcium silicate hydrate with a dreierkette-type anion. In these structures, linear finite chains of silicate tetrahedra ( Q ² units) are linked to central Ca-O layers, and tetrahedral aluminum occupies bridging positions in the chains. The main chain length and the amount of aluminum incorporated in the tetrahedral chains depend on the activator used. The detection of Q ³ silicon entities in alkaline-activated slags is discussed in relation to the possible formation of cross-linked structures that may be responsible for increased flexural and compressive strengths in AAS mortars.     

Sorption of aromatic compounds on macroporous anion exchangers based on polyacrylamide: Relation between structure and sorption behavior

The sorption of phenol, p-toluenesulfonic acid (p-TSA), Na-p-toluenesulfonate (Na-p-TS), 1,2-dihydroxy-3,5-benzene disulfonic acid disodium salt (Tiron), and 3-hydroxy-4(sulfonaphthyazo)-5,7-naphthalenedisulfonic acid trisodium salt (Poceau 4R) on the macroporus anion exchangers with acrylamide structural units (weak and strong basic anion exchangers) and on the ion exchangers with amidoxime groups were studied. The maximum specific sorption of p-TSA was almost identical with the total exchange capacity for both the weak and strong basic anion exchangers. The sorption of Na-p-TS is strongly related to the functional group structure of the anion exchangers, being significant on the strong basic anion excahngers. The maximum specific sorption of Tiron was higher tan the total exchange capacity of the strong basic anion exchangers because it is mainly dependent on the ionic exchange properties. The morphological characteristics influenced only the establishement rate of the sorption equilibrium. The sorption of Ponceau 4R, which has the highest molecular weight, is important on the strong basic anion exchangers with high permanent porosity. The sorption of the organic anions is also dependent on the number of the sulfonic groups. © 1995 John Wiley & Sons, Inc.     

Anion exchange membranes prepared from chloromethylstyrene and 2-methyl-5-vinylpyridine

Strongly basic anion exchange membranes were prepared by the radical copolymerization of chloromethylstyrene and 2-methyl-5-vinylpyridine. The formation of a three-dimensional structure and the presence of the quarternary pyridinium group were confirmed by infrared spectrum analysis and its strongly basic anion exchange properties. Their electrochemical properties and morphology were compared with those of the anion exchange membranes prepared from chloromethylstyrene-divinylbenzene and 2-methyl-5-vinylpyridine-divinylbenzene. The chloromethylstyrene-2-methyl-5-vinylpyridine membranes were proved to have larger anion exchange capacity, smaller electric resistance, larger water content, and higher permeability than the chloromethylstyrene-divinylbenzene and 2-methyl-5-vinylpyridine-divinylbenzene membranes. Also, the membranes have heterogeneity in the cross-linking structure.     

Structural Organization of Interpolymer Complexes Formed by Poly(<Emphasis Type="Italic">N</Emphasis>-vinylamides) and Poly(methacrylic acid) Chains Regularly Grafted to Polyimide in Aqueous Solutions

The formation and structural organization of interpolymer complexes formed by poly(methacrylic acid) chains regularly grafted to polyimide (molecular brushes) and macromolecules of poly(N-vinylamides) with different molecular masses are studied by polarized luminescence. The luminescent label of the anthracene structure is covalently bound to poly(methacrylic acid) chains in a brush. It is shown that in aqueous solutions the complexes under study are stabilized by hydrogen bonds formed between proton donor and proton acceptor groups of interacting chains. The formation of these complexes depends not only on the nature of poly(N-vinylamide) but also especially on its molecular mass. An increase in the molecular mass of polyamide is followed by the formation of a more compact less hydrated structure, as proved by an increase in the time of nanosecond relaxation and enhanced binding of the diphilic organic ion. The hindrance of poly(methacrylic acid) grafted chains complexed with polyvinylamide is lower than that of corresponding linear chains. This can be explained by a higher imperfection of the formed double-stranded structures. The ionization of carboxyl groups leads to the dissociation of complexes. The pH range corresponding to the highest degree of binding of acridine orange by poly(methacrylic acid) grafted chains is broader than that corresponding to the highest degree of dye binding by the linear polyacid.     

Aufbau principle of complex open-framework structures of metal phosphates with different dimensionalities

Open-framework metal phosphates occur as one-dimensional (1D) chains or ladders, two-dimensional (2D) layers, and complex three-dimensional (3D) structures. Zero-dimensional monomers have also been isolated recently. These materials are traditionally prepared by hydrothermal means, in the presence of organic amines, but the reactions of amine phosphates with metal ions provide a facile route for the synthesis, and also throw some light on the mode of formation of these fascinating architectures. Careful studies of the transformations of monophasic zinc phosphates of well-characterized structures show that the 1D structures transform to 2D and 3D structures, while the 2D structures transform to 3D structures. The zero-dimensional monomers transform to 1D, 2D, and 3D structures. There is reason to believe that the 0D monomers, comprising four-membered rings, are the most basic structural units of the open-framework phosphates and that after an optimal precursor state, such as the ladder structure, is formed, further building may occur spontaneously. Evidence for the occurrence of self-assembly in the formation of complex structures is provided by the presence of the structural features of the one-dimensional starting material in the final products. These observations constitute the beginning of our understanding of the building-up principle of such complex structures.     

Structural and electronic properties of carbon nanowires made of linear carbon chains enclosed inside zigzag carbon nanotubes

This article presents ab initio self-consistent-field crystal orbital calculations on the structural and electronic properties for recently-discovered carbon nanowires (CNWs) made of linear carbon chains inserted inside zigzag carbon nanotubes using density functional theory. The studies focus on the change of geometric structures and electronic properties upon the encapsulation. It is found that the carbon nanotubes can stabilize the encapsulated carbon chain which prefers a dimerized structure in the tube with larger diameters. The interaction between the tube and the chain becomes more obvious when the tube size decreases, leading to the change of structures and the energy bands upon encapsulation. All the CNWs we calculated are metals with zero band gap. The encapsulation of the carbon chain may modulate the electronic properties for the CNWs depending on the tube size and the filling density of carbon atoms. Therefore, it is expected that CNWs’s electronic properties can be controlled artificially by filling carbon chains with various densities of atoms into the nanotubes.     

Vibrational spectroscopy of microhydrated conjugate base anions

Conjugate-base anions are ubiquitous in aqueous solution. Understanding the hydration of these anions at the molecular level represents a long-standing goal in chemistry. A molecular-level perspective on ion hydration is also important for understanding the surface speciation and reactivity of aerosols, which are a central component of atmospheric and oceanic chemical cycles. In this Account, as a means of studying conjugate-base anions in water, we describe infrared multiple-photon dissociation spectroscopy on clusters in which the sulfate, nitrate, bicarbonate, and suberate anions are hydrated by a known number of water molecules. This spectral technique, used over the range of 550-1800 cm(-1), serves as a structural probe of these clusters. The experiments follow how the solvent network around the conjugate-base anion evolves, one water molecule at a time. We make structural assignments by comparing the experimental infrared spectra to those obtained from electronic structure calculations. Our results show how changes in anion structure, symmetry, and charge state have a profound effect on the structure of the solvent network. Conversely, they indicate how hydration can markedly affect the structure of the anion core in a microhydrated cluster. Some key results include the following. The first few water molecules bind to the anion terminal oxo groups in a bridging fashion, forming two anion-water hydrogen bonds. Each oxo group can form up to three hydrogen bonds; one structural result, for example, is the highly symmetric, fully coordinated SO(4)(2-)(H(2)O)(6) cluster, which only contains bridging water molecules. Adding more water molecules results in the formation of a solvent network comprising water-water hydrogen bonding in addition to hydrogen bonding to the anion. For the nitrate, bicarbonate, and suberate anions, fewer bridging sites are available, namely, three, two, and one (per carboxylate group), respectively. As a result, an earlier onset of water-water hydrogen bonding is observed. When there are more than three hydrating water molecules (n > 3), the formation of a particularly stable four-membered water ring is observed for hydrated nitrate and bicarbonate clusters. This ring binds in either a side-on (bicarbonate) or top-on (nitrate) fashion. In the case of bicarbonate, additional water molecules then add to this water ring rather than directly to the anion, indicating a preference for surface hydration. In contrast, doubly charged sulfate dianions are internally hydrated and characterized by the closing of the first hydration shell at n = 12. The situation is different for the (-)O(2)C(CH(2))(6)CO(2-) (suberate) dianion, which adapts to the hydration network by changing from a linear to a folded structure at n > 15. This change is driven by the formation of additional solute-solvent hydrogen bonds.     

Synthesis and thermal stability of novel anion exchange resins with spacer chains

Spacer-modified anion exchange resins were prepared by suspension copolymerization of ω-bromoalkylstyrenes or ω-bromoalkyloxymethylstyrenes with 2–8 mol % of divinylbenzene, followed by quaternization with trimethylamine. The thermal stability of the spacer-modified anion exchangers of the OH form was examined by standing the resins in deionized water at 100–140°C for 30–90 days. The anion exchangers with alkylene chains such as butylene or heptylene groups between the benzene ring and the quaternary nitrogen exhibited higher thermal stability compared with commercial, strongly basic anion exchangers with benzylic ammonium groups. The thermal stability of the exchangers with butyleneoxymethylene or hexyleneoxymethylene spacers was also higher than that of the commercial exchangers. The exchanger with the propyleneoxymethylene spacer, however, had less stability than did the commercial ones. The decreased stability of this spacer-modified exchanger is due to the accelerated degradation of the spacer chain via Hofmann elimination. The excellent stability of the anion exchangers with alkylene or alkyleneoxymethylene spacers, except propyleneoxymethylene, results from the structure of the exchangers, where there are no reactive benzylic carbons, which are attached directly to the quaternary nitrogen. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1161–1167, 1997