聚合物载体-稀土金属配合物的研究ⅩⅦ聚(苯乙烯-4-乙烯基吡啶)钕配合物在丁二烯聚合中的催化行为

聚合物载体－稀土金属配合物的研究．聚（苯乙烯－４－乙烯基吡啶）钕配合物在丁二烯聚合中的催化行为李晓莉于广谦＊李玉良（中国科学院长春应用化学研究所长春１３００２２）关键词苯乙烯，乙烯基吡啶，共聚物，钕配合物，丁二烯聚合１９９６－０４－１１收稿，１９９６...     

苯乙烯-2-乙烯基吡啶两嵌段共聚物的合成与表征

采用阴离子聚合技术合成了一系列苯乙烯 ２ 乙烯基吡啶的两嵌段共聚物（ＰＳ ｂ Ｐ２ＶＰ），并采用ＧＰＣ、ＦＴＩＲ、ＮＭＲ（１Ｈ ＮＭＲ和１３Ｃ ＮＭＲ）、ＤＭＡ等手段进行了表征．结果表明，产物为高分子量、窄分布的两嵌段共聚物，具有微相分离的两相结构     

杯芳烃钕/二正丁基镁/六甲基磷酰胺催化4-乙烯基吡啶的均聚及其与苯乙烯的共聚

聚4-乙烯基吡啶[P（4-VP）]是一种功能高分子,由于在吡啶环上有一个碱性的氮原子,它能进一步与酸反应生成各种盐,与卤代烃生成季铵盐以及与金属离子生成配合物,可用作高分子电解质,高分子试剂,高分子功能材料等,因此有不少文献对它的合成进行了报道,合成聚4-乙烯基吡啶及其与苯乙烯（St）的共聚物,除了用丁基锂作引发剂外,过渡金属的Ziegler-Natta催化剂,以及烷基铝和烷基锌等也常被用作催化剂,但用这些催化剂催化所得的聚4-乙烯基吡啶及其与苯乙烯的共聚物产率低,分子量小。     

聚(苯乙烯-丙烯酸)钕配合物催化苯乙烯与4-乙烯基吡啶共聚的研究

研究了聚(苯乙烯-丙烯酸)(PSAA)负载-氯化钕(NdCl3)配合物催化苯乙烯与4-乙烯基吡啶共聚活性。考察了Al/Nd摩尔比、聚合时间以及苯乙烯与4-乙烯基吡啶比(g.g-1)对苯乙烯与4-乙烯基吡啶共聚的影响。结果表明:这种极性单体与烯烃的共聚反应能有效发生,聚合物负载氯化钕配合物的催化性能高于同类小分子稀土氯化物,配合物催化活性随着Al/Nd摩尔比的增加而增加,随聚合时间的延长而降低,反应时间为2 h时配合物催化活性最高;4VPy和St摩尔比为4∶2时产率较高;得到的聚合物具有良好的耐热性。     

丙烯酸丁酯/4-乙烯基吡啶共聚物与聚氯乙烯共混相容性的研究

合成了系列丙烯酸丁酯/4-乙烯基吡啶共聚物[P(BAVP)].以四氢呋喃为溶剂,用溶剂浇铸法制备了一系列P(BAVP)与聚氯乙烯(PVC)的共混物.动态力学性能测试表明:共混物中吡啶环含量高于1%(摩尔百分含量)的共混物呈均相,即共聚物与PVC相容.P(BAVP)/PVC共混物的T_g随PVC含量和乙烯基吡啶链段含量增加而提高.由红外光谱分析推论出:P(BAVP)分子间的作用力比PBA分子间作用力弱,从而使P(BAVP)与PVC的相容性提高.     

芳基碘化物[聚(4-乙烯基吡啶)]钯(0)催化下的乙烯基化反应

前文报道了聚[(苯乙烯)联吡啶]钯(0)催化剂在芳基碘化物乙烯基化反应中的应用,其催化剂的活性较高,但连续使用三次后,活性明显降低.本文继续报道能用于芳基碘化物乙烯基化反应的高分子负载钯催化剂的合成和应用.据文献报道能用于芳基碘化物乙烯基化的高分子负载钯催化剂,都是通过多步反应将配体导入聚苯乙烯骨架上合成的,操作比较复杂.为了简化催化剂的制备方法,我们探索了用聚(4-乙烯基吡啶)作高分子载体的可能性.将4 乙烯基吡啶与苯乙烯共聚,加入2%二乙烯基苯作交联剂,生成的共聚物用醋酸钯处理后,加氢化铝锂还原,得到每克含钯7.0mg、氮33.7mg的催化剂,并研究了它在芳基碘化物与苯乙烯、丙烯酸和丙烯酰胺的反应中的催化性能.     

聚(4-乙烯基吡啶)-b-聚环氧乙烷-b-聚(4-乙烯基吡啶)的合成及其用于毛细管电泳分离碱性蛋白质

用原子转移自由基聚合(ATRP)法合成了结构可控的三嵌段共聚物聚(4-乙烯基吡啶)-b-聚环氧乙烷-b-聚(4-乙烯基吡啶)(P4VP-b-PEO-b-P4VP).用核磁共振氢谱和凝胶渗透色谱对该共聚物进行了表征;将该共聚物作为毛细管物理吸附涂层,用毛细管电泳对碱性混合蛋白质进行了分离.结果表明:蛋白质的分离效率随着P...     

丙烯酰胺与4-乙烯基吡啶共聚合反应竞聚率

测定了丙烯酰胺与4－乙烯基吡啶共聚反应的竞聚率。用紫外分光光度法测定了不同浓度的4－乙烯基吡啶均聚物的吸光度，从而求出在低转化率不同初始单体组成的共聚物中4－乙烯基吡啶含量。用FR和KT两种作图法及YBR计算法对单体的竞聚率进行计算和比较。结果表明：KT法和YBR法计算法较为准确，4－乙烯基吡啶的竞聚率和丙烯酰胺的竞聚率分别为γrVP=0.636,γAM=0.379。     

共聚物铑配合物催化甲醇羰基化速控步骤的理论研究

采用以原子重叠及电子离域的分子轨道理论ＡＳＥＤ ＭＯ（含原子对排斥的ＥＨＭＯ法）为基础的结构自动优化法，对共聚物铑配合物催化甲醇羰基化制乙酸反应速率控制步骤 氧化加成进行了理论研究．计算了不同共聚物配体形成的铑催化剂与碘甲烷的氧化加成反应途径，并得到反应活化能，分析了氧化加成反应过程中的电子转移和空间因素对活化能的影响，计算结果与实验结果是相符的，并从理论上解释了２ 乙烯基吡啶形成的共聚物铑配合物催化活性高于４ 乙烯基吡啶形成的共聚物铑配合物催化活性的原因．     

由特殊相互作用导致的高分子间的络合Ⅸ.聚(苯乙烯-co-4-乙烯基苯酚)/聚(苯乙烯-co-4-乙烯基吡啶)在本体中的相容-络合行为

采用结合物理老化技术的示差扫描量热法（ Ｄ Ｓ Ｃ） 以及非辐射能量转移荧光光谱法（ Ｎ Ｒ Ｅ Ｔ） 研究了聚（ 苯乙烯 ｃｏ ４ 乙烯基苯酚） （ Ｓ Ｔ Ｖ Ｐｈ） 与聚（ 苯乙烯 ｃｏ ４ 乙烯基吡啶）（ Ｓ Ｔ Ｖ Ｐｙ） 共混体系在本体中的相容与络合行为．当 Ｓ Ｔ Ｖ Ｐｈ 中 Ｏ Ｈ 含量为３ ,６ ,９ ｍ ｏｌ ％ 时,可以分别与吡啶基含量是２５ ,５０ ,７５ ｍｏｌ ％ 的 Ｓ Ｔ Ｖ Ｐｙ 实现相容, Ｏ Ｈ 含量更高时还可进一步形成络合,表现为远较 Ｆｏｘ 方程预示值高的 Ｔｇ 和窄的转变温度区间．此外,还讨论了浇膜溶剂对相容与络合的影响     

表面活性剂对苯胺电聚合的影响

利用胶束在电极一有面的定向及增溶作用研究了表面活性剂对苯胺电聚合的影响，结果表明：在阴离子表面活性剂十二烷基硫酸钠（ＳＤＳ）胶束体系中，胶束介质能催化苯胺的电聚合反应，使其氧化电位负移，减少膜的降解，提高膜的稳定性，同时，也使得聚合速率增大，在０．１ｍｏｌ／Ｌ的ＳＤＳ的胶束溶液中，其聚合效率提高到不含ＳＤＳ的纯体系的２５倍，在含有１０＾－４ｍｏｌ／ＬＳＤＳ的硫酸溶液中，聚苯胺（ＰＡＮ）的成核生长为     

Interaction of acridine orange monohydrochloride dye with sodiumdodecylsulfate, (SDS) cetyltrimethylammoniumbromide (CTAB) and p-tert-octylphenoxypolyoxy ethanol (Triton X 100) surfactants

Summary Results of spectrophotometric, conductometric and dialysis studies on the interaction of acridine orange monohydrochloride dye with sodiumdodecylsulfate (anionic), cetyltrimethylammoniumbromide (cationic) and Triton X 100 (nonionic) surfactants have been reported. The anionic surfactant, SDS has been observed to undergo both electrostatic and hydrophobic interactions with the dye cation. Aggregation of the dye molecules can be destroyed when the surfactant is in large excess, whereas, excess dye can check micellization of SD S. At a ratio of AO:SDS=1:7 and above, dye embedded mixed micelles are formed. These remain in a separate phase, probably as coacervates. At lower ratios than 1:7, aggregation of dye molecules is induced, which being complexed with SDS become stabilized as colloids. The colloid and the coacervate have been observed to be thermally stable, negatively charged materials that can be broken by salts, and cations of higher valency are more effective in this regard. An 1:3 = AO:SDS colloid has beeen found to be sufficiently large like the coacervates to pass through a membrane having cut off permeability for molecular weights 12,000 and above. All the above features of AO-SDS interaction have been observed to be absent for AO-CTAB and AO-TX 100 systems, Even hydrophobic interaction has played an insignificant role in these cases. Thus, the dye cation, the cationic and the nonionic surfactants have almost retained their self physicochemical identities in solution in the presence of each other. Electrostatic interaction is thus the primary requirement for acridine orange-surfactant (anionic) system; the hydrophobic effect is secondary and may become co-operative.With 9 figures and 2 tables     

Rotational diffusion of organic solutes in surfactant-block copolymer micelles: role of electrostatic interactions and micellar hydration

Rotational diffusion of a cationic solute rhodamine 110 and a neutral solute 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole, DMDPP has been examined in the surfactant-block copolymer system of sodium dodecyl sulfate (SDS) and poly(ethylene oxide)20-poly(propylene oxide)70-poly(ethylene oxide)20 (P123). In this study, the mole ratio of SDS to P123 was varied from 0 to 5 in steps of one unit, to investigate the role of electrostatic interactions and micellar hydration on solute rotation. It has been noticed that there is a significant enhancement in the average reorientation time of rhodamine 110, when [SDS]/[P123] increased from 0 to 1. This has been rationalized on the basis of migration of rhodamine 110 from the interfacial region of P123 micelles to the palisade layer (corona region) due to the electrostatic interaction with negatively charged head groups of SDS, whose tails are embedded in the polypropylene oxide core. Further increase in the mole ratio of SDS to P123 has resulted in only a marginal decrease in the average reorientation time of rhodamine 110, which is probably due to the solute molecule experiencing a microenvironment similar to the interfacial region of SDS micelles. In contrast, a gradual decrease has been observed in the average reorientation time of DMDPP with [SDS]/[P123], which is due to the increase in hydration levels in the palisade layer (corona region) of the micelle. These explanations are consistent with the structure of the SDS-P123 micellar system that has been deduced from neutron scattering and viscosity measurements recently.     

正、负离子混合表面活性剂双水相系统相图及微观 结构研究

研究了水/十二烷基硫酸钠(SDS)/十六烷基三甲基溴化胺(CTAB)三元相图上的双水相区及其相关性质,研究发现：该系统在两个非常狭窄的区域能够形成双水相,SDS过量的双水相区具有类似浊点的性质,上相有明显的偏光现象,而CTAB过量的双水相区则具有Krafft点性质,上相偏光现象较弱。冷冻蚀刻显微镜观察双水相的微观结构表明,上相为层状结构,下相一般为球状结构。双水相的体积比对正、负离子表面活性剂比例的微小变化非常敏感。     

Capillary electrophoretic studies on the migration behavior of cationic solutes and the influence of interactions of cationic solutes with sodium dodecyl sulfate on the formation of micelles and critical micelle concentration

The migration behavior of cationic solutes and influences of the interactions of cationic solutes with sodium dodecyl sulfate (SDS) on the formation of micelles and its critical micelle concentration (CMC) were investigated by capillary electrophoresis at neutral pH. Catecholamines and structurally related compounds, including epinephrine, norepinephrine, dopamine, norephedrine, and tyramine, which involve different extents of hydrophobic, ionic and hydrogen-bonding interactions with SDS surfactant, are selected as cationic solutes. The dependence of the effective electrophoretic mobility of cationic solutes on the concentration of surfactant monomers in the premicellar region provides direct evidence of the formation of ion-pairs between cationic solutes and anionic dodecyl sulfate monomers. Three different approaches, based on the variations of either the effective electrophoretic mobility or the retention factor as a function of surfactant concentration in the premicellar and micellar regions, and the linear relationship between the retention factor and the product of a distribution coefficient and the phase ratio, were considered to determine the CMC value of SDS micelles. The suitability of the methods used for the determination of the CMC of SDS with these cationic solutes was discussed. Depending on the structures of cationic solutes and electrophoretic conditions, the CMC value of SDS determined varies in a wide concentration range. The results indicate that, in addition to hydrophobic interaction, both ionic and hydrogen-bonding interactions have pronounced effects on the formation of SDS micelles. Ionic interaction between cationic solutes and SDS surfactant stabilizes the SDS micelles, whereas hydrogen-bonding interactions weakens the solubilization of the attractive ionic interaction. The elevation of the CMC of SDS depends heavily on hydrogen-bonding interactions between cationic solutes and SDS surfactant. Thus, the CMC value of SDS is remarkably elevated with catecholamines, such as epinephrine and norepinephrine, as compared with norephedrine. In addition, the effect of methanol content in the sample solution of these cationic solutes on the CMC of SDS was also examined.     

Aqueous Two‐Phase System (ATPS) Containing Gemini (12‐3‐12,2Br−) and SDS I: Phase Diagram and Properties of ATPS

Two phases coexist in an aqueous system that contains the two surfactants cationic gemini 12‐3‐12,2Br? and anionic SDS. An aqueous two‐phase system (ATPS) is formed in a narrow region of the ternary phase diagram different from that of traditional aqueous cationic‐anionic surfactant systems. In that region, the molar ratio of gemini to SDS varies with the total concentration of surfactants. ATPS not only has higher stability but also has longer phase separation time for the new systems than that of the traditional system. Furthermore, the optical properties of ATPS are different at different total concentrations. All of these experimental observations can be attributed to the unique properties of gemini surfactant and the synergy between the cationic gemini surfactant and the anionic surfactant SDS.     

Characterization and Aggregation Behaviors of Mixed DDAB/SDS Solution With and Without Poly(4-styrenesulfonic Acid-Co-Maleic Acid) Sodium

Synthetic vesicles are formed by cationic and anionic surfactants, didodecyldimethylammonium bromide (DDAB), and sodium dodecylsulfate (SDS). The morphology, size, and aqueous properties of cationic/anionic mixtures are investigated at various molar ratios between cationic and anionic surfactants. The charged vesicular dispersions made of DDAB/SDS are contacted or mixed with negatively charged polyelectrolyte, poly(4-styrenesulfonic acid-co-maleic acid) sodium (PSSAMA), to form complexes. Depending on DDAB/SDS molar ratio or PSSAMA/vesicle charge ratio, complexes flocculation or precipitation occur. Characterization of the cationic/anionic vesicles or complexes formed by the catanionic vesicles and polyelectrolytes is performed by transmission electron microscope (TEM), dynamic light scattering (DLS), conductivity, turbidity, and zeta potential measurements. The size, stability, and the surface charge on the mixed cationic/anionic vesicles or complexes are determined.     

二苯胺重氮盐与十二烷基硫酸钠在水溶液中的相互作用

报道了二苯胺-4-重氮盐(DDS)与十二烷基硫酸钠(SDS)在水溶液中的相互作用.实验结果表明,体系粘度随SDS/DDS物质的量比(ξ)的变化而急增急降.当ξ=0～0.9时,二者形成沉淀,体系的粘度基本不变;当ξ=1.9～2.3时,沉淀溶解并伴随着体系粘度急增,最高粘度达初始值的2520倍;之后,随ξ的增大,体系粘度迅速下降至初始值.对DDS-SDS聚集体的微观结构与体系粘度的关系进行了初步讨论.同时发现体系粘度是光敏性的,紫外光照可使其迅速下降.     

Adsorption of cationic cellulose derivative/anionic surfactant complexes onto solid surfaces. II. Hydrophobized silica surfaces

The effect of the anionic surfactant SDS (sodium dodecyl sulfate) on the adsorption behavior of cationic hydroxyethyl cellulose (Polymer JR-400) and hydrophobically modified cationic cellulose (Quatrisoft LM-200) at hydrophobized silica has been investigated by null ellipsometry and compared with the previous data for adsorption onto hydrophilic silica surfaces. The adsorbed amount of LM-200 is found to be considerably larger than the adsorbed amount of JR-400 at both surfaces. Both polymers had higher affinity toward hydrophobized silica than to silica. The effect of SDS on polymer adsorption was studied under two different conditions: adsorption of polymer/SDS complexes from premixed solutions and addition of SDS to preadsorbed polymer layers. Association of the surfactant to the polymer seems to control the interfacial behavior, which depends on the surfactant concentration. For the JR-400/SDS complex, the adsorbed amount on hydrophobized silica started to increase progressively from much lower SDS concentrations, while the adsorbed amount on silica increased sharply only slightly below the phase separation region. For the LM-200/SDS complex, the adsorbed amounts increased progressively from very low SDS concentrations at both surfaces, and no large difference in the adsorption behavior was observed between two surfaces below the phase separation region. The complex desorbed from the surface at high SDS concentrations above the critical micelle concentration. The reversibility of the adsorption of polymer/SDS complexes upon rinsing was also investigated. When the premixed polymer/SDS solutions at high SDS concentrations (>5 mM) were diluted by adding water, the adsorbed amount increased due to the precipitation of the complex. The effect of the rinsing process on the adsorbed layer was determined by the hydrophobicity of the polymer and the surface.     

Studies on the Interaction of Surfactants with Cationic Dye by Absorption Spectroscopy

The interaction of methyl violet, a cationic dye, with various surfactants, viz. anionic (SDS), nonionic (Triton X-100), and cationic (CTAB), has been investigated spectrophotometrically in submicellar and micellar concentration range. While in the submicellar concentration region of SDS the higher aggregates of the dye are found, in the micellar concentration region the monomer of the dye predominates. With nonionic surfactant the dye is solubilized primarily as the monomer. CTAB produces no perturbation to the visible spectra of the dye. In the presence of strong electrolytes such as NaNO(3) and NaCl the dye aggregates are formed at a much lower SDS concentrations. Copyright 2000 Academic Press.