磺化聚苯醚离聚体的合成及溶液性质研究

合成一系列磺化度的磺化PPO(S-PPO),以磺化度为20.9mol％的S-PPO的钠盐和锂盐为代表,研究其在四氢呋喃/甲醇混合溶剂中的离聚体行为。结果表明,S-PPO离聚体在溶液中的链聚集状态与聚合物浓度、反离子半径和温度密切相关。     

磺化聚苯醚离聚体的溶液性质

研究了磺化度为20.9mol％的磺化聚苯醚(S-PPO)的钠盐和锂盐在四氢呋喃/甲醇混合溶剂中的离聚体行为。S-PPO离聚体在溶液中的链聚集状态与聚合物浓度、阳离子半径密切相关。当Na-SPPO的浓度高于3g/dL时,在30～40℃范围内其聚集度DA与浓度C的关系为:DA=ke~(εc)常数K和β分别表示为与发现链聚集的起始浓度和链聚集速率相关的常数。     

用激基缔合物荧光研究聚苯乙烯-聚甲基丙烯酸甲酯嵌段共聚物在溶液中的分子构型

聚苯乙烯在溶液中的激基缔合物荧光被发现以来一直引起人们的兴趣^{[ 1, 2]}. 聚苯乙烯激基缔合作用主要与处于基态的苯环层叠对的形成有密切关系. 其形成方式主要有(1)符合n= 3规则的相邻苯环间的相互作用.(2)主链上非相邻苯环间由于链段的卷曲而相互作用.(3)分属于不同主链上的苯环相互贯穿时的相互作用. 由于激基缔合作用是近程作用, 因此利用它研究聚合物线团在稀溶液的变化及由稀溶液到浓溶液的变化是十分有效的^{[ 3]}. 嵌段聚合物在形成胶束时, 一种聚合物分子链段形成核, 在核内大分子链段相互缠结, 相互贯穿. 而另一种聚合物分子链段形成壳, 其链段较为舒展. 因此利用激基缔合物荧光技术研究分子链段在核内的变化也应是十分有效的. 本文研究聚苯乙烯-聚甲基丙烯酸甲酯嵌段共聚物体系。     

新型含糖嵌段共聚物PEO-b-P(lys-ML)的合成及其在水中的聚集行为

用氨端基PEO作大分子引发剂 ,引发lys(Z) NCA开环聚合制得共聚物PEO b P(lys Z) ,经脱除保护基———苄氧羰基 (Z)后 ,与麦牙糖内酯反应制得水溶性嵌段共聚物聚环氧乙烷 b 聚 (Nε 麦芽糖酰 L 赖氨酸 )(PEO b P(lys ML) ) .用荧光方法研究了PEO b P(lys ML)在水溶液中的聚集行为 .结果表明 ,在某一临界聚集浓度 (Criticalaggregationconcentration ,简称cac)以上 ,聚合物在水中自聚集形成胶束型聚集体 ;在浓度低于cac时 ,加入与葡萄糖基团有特殊相互作用的凝集素 (ConcanavalinA ,简称ConA)也能诱导聚合物形成聚集体 ,此类聚集体对于开发新型药物载体有重要意义     

碘化丁基橡胶离聚体在溶液中的聚集行为（I）：ESR谱研究

用ＥＳＲ谱考察了磺化丁基橡胶锰盐（Ｍｎ－ＳＩＩＲ）离聚体在二甲苯／醇（少量）混合溶剂中的离子聚集行为。结果表明，在所考察的范围内，浓度及磺化度增大时ＥＳＲ谱的形状变不大，这反映了离子聚集程度并没有发生明显变化，另外，极性共溶剂（醇）增多时，线分辨度增大，反映了离子聚庥程度下降；温度升高时谱线变模糊，反映了离子聚集程度增大，这些结果有力地支持了Ｌｕｎｄｂｅｒｇ等人提出的离聚体溶液粘度变化平衡式。     

交联网络和浓溶液中高分子链运动的NMR研究 Ⅱ质子自旋-自旋弛豫与凝胶和浓溶液体系中高分子链段运动

用自旋－自旋弛豫时间考察了线型聚苯乙烯溶液与溶胀交联聚丙烯酰胺－丙烯酸凝胶的质子弛豫行为。发现在溶胀交联体系中，不论交联度高低，聚丙烯酰胺－丙烯酸质子的弛豫时间弛豫都呈现出双指数衰减特征；而在线型溶液体系中，聚苯乙烯质子的弛豫时间弛豫符合单指数衰减特征。说明在线性聚苯乙烯溶液中，高分子的链段运动是一种均匀行为，而在溶胀交联聚丙烯酰胺－丙烯酸体系中，不论交联度高低，高分子链段运动始终存在快慢不同的两部分。     

荧光淬灭法研究疏水缔合共聚物(PAM-b-PPOEA)_n自组装聚集数

运用荧光淬灭技术,包括稳态荧光淬灭法(SSFQ)和时间分辨荧光淬灭法(TRFQ),研究了疏水缔合水溶性丙烯酰胺2苯氧基丙烯酸酯多嵌段共聚物[P(AM POEA)]在水溶液中自组装的聚集数.这类聚合物在水溶液中易形成胶束状聚集体,探针芘分子和淬灭剂二苯酮增溶于疏水微区,荧光测定结果很好地符合Poisson淬灭模型.实验结果表明聚合物链结构、聚合物浓度和无机盐对聚集体的尺寸具有重要影响.聚合物自组装聚集数NA随疏水单体含量的增加和疏水嵌段长度的减小而增大,同时也随聚合物浓度和NaCl浓度增加而增大.另外对聚合物链结构、聚集数和溶液粘度的相互关系进行了讨论.     

双亲嵌段共聚物PSt-b-PAA在甲苯中的自聚集行为

以α-溴乙苯为引发剂,溴化亚铜为催化剂,2,2'-联吡啶为配体,用原子转移自由基聚合(ATRP)法合成了结构一定的嵌段共聚物聚苯乙烯-b-聚丙烯酸丁酯(PSt-b-PBA).经水解制备了双亲性嵌段共聚物聚苯乙烯-b-聚丙烯酸(PSt-b-PAA);采用单溶剂溶解法配制了PSt-b-PAA在甲苯中的反胶束溶液;以极性荧光化合物N-1-萘乙二胺盐酸盐(NEAH)为极性微区探针,用荧光光谱法并配合透射电镜观察探索了双亲嵌段共聚物PSt-b-PAA在甲苯溶液中的自聚集行为,考察了双亲性嵌段共聚物浓度、链结构及温度等因素对反胶束化行为的影响规律.结果表明,亲水链PAA短而亲油链PSt长的双亲嵌段共聚物PSt-b-PAA,用单溶剂溶解法可使其在甲苯中发生自聚集,形成以亲水段为核,疏水段为壳的星状反胶束结构;反胶束为10-20nm的球形聚集态结构;PSt-b-PAA的自聚集行为及临界胶束浓度与分子链的微结构和温度等因素相关,且随着共聚物浓度的增大,小胶束会逐渐结合形成大的纺垂状聚集体.     

含氟嵌段共聚物离聚体的合成表征及其性能研究

嵌段共聚物离聚体具有独特的形态和固体及溶液性质 ,在热塑性弹性体、极性材料与非极性材料共混相溶剂和粘度调节剂等领域具有十分广阔的应用前景 ,引起了人们的普遍关注 .文献报道较多的是聚苯乙烯 乙烯 丙烯[1] 、聚苯乙烯 乙烯 丁烯 苯乙烯[2 ] 、聚苯乙烯 异丁烯 苯乙烯[3 ] 等共聚物中 ,聚苯乙烯链段部分磺化后所得离聚体的合成与性质研究 .众所周知 ,含氟聚合物具有低表面能和高表面活性等特性 ,因而将含氟基团引入到嵌段共聚物离聚体中有望开发出一种新型的特殊功能材料 .原子转移自由基聚合 (ATRP)自 1 995年问世以来 ,已成功…     

交联网络和浓溶液中高分子链运动的NMR研究Ⅲ.质子自旋-晶格弛豫时间与凝胶和浓溶液体系中高分子链段的运动

用自旋－晶格弛豫时间（Ｔ１）研究了溶胀的交联聚丙烯酰胺－丙烯酸网络和线型聚苯乙烯溶液中质子的弛豫行为。交联网络中，随着交联度增大，Ｔ１ＣＨ／Ｔ１ＣＨ２的值由１．１７逐渐趋近于１；而线型聚苯乙烯溶液中，Ｔ１ＣＨ／Ｔ１ＣＨ２的值由最稀浓度下的１．７过渡到１。说明在交联网络中，交联度很低时，链段的运动已经相当受约束；但交联度很大时，充分溶胀的交联网络中链段运动仍有一定自由度。而在线型高分子浓溶液中，链段的运动严重受阻，导致自旋扩散效应非常完全，彻底平均掉了各质子间Ｔ１时间的差异。     

Self-assembly of Sulfonated Polystyrene Ionomers in Chloroform

Light scattering and electric birefringence were used to determine the dimensions and extent of aggregation of dilute solutions of sodium sulfonated polystyrene ionomers with sulfonation levels of 0.5, 1.35, 2.6 and 5.8 mol% in chloroform. It was found that in solutions of ionomers with sulfonation level 1.35 and more the equilibrium between single chains and aggregates consisting of two and more chains is observed. These data were analyzed using the “open” association model. It was shown that an increase in the sulfonation level of ionomers results in a decrease in the hydrodynamic radius of single chain. On the other hand, it was established that an increase in sulfonation level leads to increase in the size of aggregate consisting of two chains. More pronounced expansion of ionomer chains incorporated into aggregate was found for ionomers with high sulfonation level.     

磺化聚苯乙烯镧离子型聚合物的稀溶液性质

聚电解质行为;比浓粘度;电解质;磺化聚苯乙烯镧离子型聚合物的稀溶液性质     

Fluorescence and light-scattering studies on the formation of stable colloidal nanoparticles made of sodium sulfonated polystyrene ionomers

The lightly sulfonated polystyrene ionomer is only soluble in some organic solvents, such as toluene and tetrahydrofurnan (THF). The mixture of its organic solution with water normally leads to macroscopic phase separation, namely precipitation. In this study, using the steady-state fluorescence, the nonradiative energy transfer and dynamic laser light scattering, we demonstrate that the sulfonated polystyrene ionomers can form stable colloidal nanoparticles if the THF solution of the ionomers is dropwisely added into an excessive amount of water, or vice verse, water is added in a dropwise fashion into the dilute ionomer THF solution under ultrasonification or fast stirring. The hydrophobic core made of the polystyrene backbone chains is stabilized by the ionic groups on the particle surface. Such formed stable nanoparticles have a relatively narrow size distribution with an average diameter in the range of 5–12 nm, depending on the degree of sulfonation, the initial concentration of the ionomer THF solution, and the mixing order. This study shows another way to prepare surfactant-free polystyrene nanoparticles. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35 : 1593–1599, 1997     

Composition dependence of glass transition temperature of sulfonated-polystrene ionomers

The glass transition temperatures of alkali (Na, K, Rb, Cs) and alkaline-earth (Ba, Sr, Ca, Mg) ionomers of sulfonated polystyrenes (PSSA) with 3.4, 6.9, 12.7, and 16.7% of the styrene moieties sulfonated are reported. For the alkali-metal PSSA ionomers, T_g depends on the degree of sulfonation, at least up to 13%, but not strongly on the nature of the cation. For the alkaline-earth analogs T_g does not depend strongly on either the cation or the degree of sulfonation until the 16.7% level is reached. These and other reported data are discussed in terms of the role of cations in determining morphology.     

Self-organization of sulfonated polystyrene ionomers with various contents of ionogenic groups in toluene: Neutron scattering study

The structural organization of sulfonated polystyrene-based ionomers containing different amounts of sodium sulfonate groups (SO₃Na) in the concentration range from 0.5 to 5.8 mol % in deuterotoluene has been studied by cold neutron scattering. An analysis of molecular correlations shows that ionomer chains retain the Gaussian coil conformation even at a degree of sulfonation of 5.8 mol %, when the distance between ionogenic groups along a chain is comparable with the Kuhn segment length. At a content of SO₃Na groups of 1.35 mol %, the mutual penetration of polymer chains predominates and is accompanied by the formation of associates including up to seven macromolecules (effective chains) and functioning as main structural elements of the system. At a higher content of SO₃Na groups, the mutual penetration of macromolecules becomes weaker owing to the enhanced intramolecular association of ionogenic groups. As a result, the effective chains with sizes smaller than the size of the PS coil arise. These chains are composed of 1–2 ionomer macromolecules and are compacted structures in which the concentration of PS units is a factor of 4 higher than the concentration of units in the nonsulfonated PS coil. The self-organization of such particles in toluene yields secondary structures in the form of clusters composed of four to five effective chains.     

Water vapor sorption and diffusion in sulfonated aromatic polyamides

In this contribution polyamides with different sulfonation degrees were directly synthesized from a combination of sulfonated and nonsulfonated diamines and isophthaloyl chloride. They were then used as dense membranes to study water sorption and mass transport properties. The polymers were characterized by their inherent viscosity and by spectroscopic methods, and the water vapor unsteady sorption phenomena were studied using a gravimetric technique. The effect of sulfonation substitution concentration in these polymers produces very interesting and original results in a number of properties such as the ionic exchange capacity, water equilibrium sorption and diffusivity. Obtained results are discussed and explained in the light of existing theories. Sorption behavior for polymers with a low sulfonation degree, up to 30%, can be explained with Langmuir equation. With larger substitution degree (40 and 60%) an additional mechanism must be assumed to explain sorption data. Assuming the presence of two phases helps to explain the observed diffusivity results. The mass transport mechanism is assumed to be Fickian. When water activity is low diffusivity systematically decreases as the degree of sulfonation increases. However, as water activity increases less sulfonated and nonsulfonated (PA0, PA20 and PA30) behave completely different from PA40 and PA60. The first group of polymers shows a tendency to decrease the rate of diffusion as water activity increases while the second group shows the opposite behavior, with a maximum in diffusivity at intermediate water activities. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2007–2014, 2007     

Conformational properties of chains and supramolecular structures of sulfonated polystyrene ionomers in <Emphasis Type="Italic">D</Emphasis>-benzene

The method of small-angle cold-neutron scattering is used to study the conformational properties of chains of sulfonated polystyrene-based ionomers containing different amounts of sodium sulfonate groups SO₃Na (0.5, 1.35, and 2.6 mol %) and the character of their self-organization in D-benzene. An analysis of the momentum transfer dependence of scattering intensity shows that the conformation of ionomer chains remains close to the Gaussian conformation, regardless of the content of ionogenic groups. It is found that, in local portions within a segment, the rigidity of chains increases owing to formation of physical crosslinks between chains arising from electrostatic interactions of ionogenic groups. Interchain interactions involving multiplets of ionogenic groups lead to the self-organization of ionomers into supramolecular structures (associates) that manifest themselves as Gaussian chains and include 13–18 macromolecules at moderate and high degrees of sulfonation of PS. When the centers of gravity approach each other at the distance of a diameter (40–70 nm), the associates come into contact and give rise to clusters.     

磺化SIS及其离聚物的稀溶液性质

嵌段共聚物;比浓粘度;特性粘液;磺化SIS及其离聚物的稀溶液性质     

A semi-empirical approach to the modeling of the electrophoretic mobility in free solution: application to polystyrenesulfonates of various sulfonation rates

This work focuses on the understanding of the electrophoretic behavior of flexible chains of polystyrenesulfonates (PSSs) in free solution. It deals mainly with the variation of the electrophoretic mobility with (i) the polymerization degree (N) of fully sulfonated PSSs and (ii) the sulfonation rate of randomly sulfonated PSSs. In both cases, the electrophoretic mobility was modeled following a semi-empirical approach which involves parameters retaining a physical meaning. Fully sulfonated PSS oligomers, having a length smaller than or similar to the Debye length, exhibit a particular electrophoretic behavior, in-between that observed for multicharged small molecules and that for polyelectrolytes. The electrophoretic mobility of these oligomers increases strongly with N, which is attributed to a hydrodynamic coupling between monomers. Then the mobility is maximum for an N of about 10, for which the PSS oligomers are still in a rod-like conformation. Afterwards, as N increases and the PSSs are larger than the Debye length, the electrophoretic mobility decreases slowly until it reaches a constant value corresponding to the free-draining behavior. Next, the electrophoretic behavior of long PSS (N about 1,200) differing in their sulfonation rates was investigated. The effective charge rates were determined independently by conductimetric measurements and the mobilities were modeled as a function of the sulfonation rate. The PSS behavior observed was compared to the one previously reported for classical polyelectrolytes having hydrophilic backbones, such as copolymers of poly(acryamide-coacrylic acid). A specific behavior has been pointed out for these partially sulfonated PSSs, which is attributed to the hydrophobicity of their backbone. Finally, it is shown that separations of PSSs of different sulfonation rates can be obtained with electrolytes containing an anionic surfactant or methanol.     

离聚体溶液粘度方程

离聚体（ionomer）是指合少量离子基团（低于15％mo）的聚合物．在低极性溶剂中，离子基团发生聚集，因而离聚体溶液的粘性行为明显不同于普通高分子溶液．很多实验表明［1］，用于描述普通高分子溶液粘性行为的哈金斯公式并不适用于描述离聚体溶液的粘性行为．因此，到目前为止，对离聚体溶液的离子聚集行为及粘性行为的考察或者是定性的，或者是通过图表曲线直接描述的．本文提出适用于高聚体溶液的半经验关系式，并用实验数据验证，以求更深入和更系统地研究离聚体溶液的粘性行为．1实验部分采用两种分子量的丁基胶（牌号286，加拿大产品…