聚酰胺的合成——N-羟基-5-降冰片烯-2,3-双甲酰亚胺的双活性酯与脂族二胺间在温和条件下的缩聚反应

<正> 在合成聚酰胺的研究中,关于由N-羟基化合物O,O′-双酰基衍生物与二元胺在温和条件下合成聚酰胺的报道较少。Overberger及ebenda首先研究了N-羟基丁二酰亚胺的双活性酯及N-羟基邻苯二甲酰亚胺的双活性酯与派嗪间的缩聚反应。Ueda、Imai等则报道了另两类活性双酯,如1-羟基苯并三氮唑的双活性酯及O,O′-间苯二甲酰双肟与二元胺间的缩聚合成聚酰胺的结果。     

聚苯乙烯树脂固载聚乙二醇及吡啶翁盐的合成及其活性评价

以氯甲基化聚苯乙烯为原料，先后接枝聚乙二醇及吡啶，合成了双中心固载相转移催化剂－交联聚苯乙烯固载聚乙二醇400及吡啶翁盐，并对氯甲基化聚苯乙烯树脂、聚苯乙烯固载聚乙二醇树脂、聚苯乙烯固载吡啶翁盐树脂及双中心树脂进行了红外光谱测试和分析。通过醋酸钾与溴苄的反应，对各催化剂进行了活性评价。发现固载双中心相转移催化剂的活性明显高于各单向中心固载相转移催化剂。     

聚苯乙烯树脂固载聚乙二醇及吡啶weng盐的合成及其活性评价

以氯甲基化聚苯乙烯为原料，先后接枝聚乙二醇及吡啶，合成了双中心固载相转移催化剂──交联聚苯乙烯固载聚乙二醇４００及吡啶weng盐，并对氯甲基化聚苯乙烯树脂、聚苯乙烯固载聚乙二醇树脂、聚苯乙烯固载吡啶weng盐树脂及双中心树脂进行了红外光谱测试和分析，通过醋酸钾与溴节的反应，对各催化剂进行了活性评价，发现固载双中心相转移催化剂的活性明显高于各单中心固载相转移催化剂。     

（苯乙烯—丁二烯—环氧乙烷）多嵌段共聚物的合成及表征

α,ω—双羟基聚苯乙烯与α,ω—双羟基聚丁二烯及聚乙二醇为预聚体,以2,4-甲苯二异氰酸酯为偶联剂,聚合得到(苯乙烯-丁二烯-环氧乙烷)多嵌段共聚物。研究了聚合条件的影响。产物分别用热环已烷及水萃取提纯。并用IR、~1HNMR、GPC、动态粘弹谱及透射电子显微镜进行了表征。     

活性自由基聚合法制备以C60封端的聚苯乙烯

通过活性自由基聚合的方法制备了以２,２,６,６－四甲基－４－羟基呱啶氮氧自由基（ＴＥＭＰＯＬ）封端的聚苯乙烯大分子,实验结果证明该反应体系是一个典型的活性自由基聚合体系,同时研究了ＴＥＭＰＯＬ／ＡＩＢＮ的比例及ＡＩＢＮ的含量对聚合反应的影响。用以ＴＥＭＰＯＬ封端的聚苯乙烯和Ｃ６０反应,制得了Ｃ６０的聚苯乙烯高分子衍生物,紫外和ＧＰＣ结果均证明Ｃ６０已连接到聚苯乙烯的长链上,ＧＰＣ的结果还证明,Ｃ６     

邻苯二酚双苯醚的合成与抑菌活性研究

以硝基氯苯和羟基二苯醚为底物合成了6个硝基邻苯二酚双苯醚类化合物、6个氨基邻苯二酚双苯醚类化合物和6个羟基邻苯二酚双苯醚类化合物,所有这些新化合物的结构经元素分析、红外光谱、质谱及1H NMR确证.并研究了它们的抑菌活性,初步生物活性测试表明硝基、氨基芳醚类化合物的抑菌或杀菌活性较差,而羟基芳醚类化合物却有强的抑菌能力.     

巯基-内酰胺引发活性自由基接枝聚合制备凹凸棒土/聚苯乙烯杂化粒子的研究

通过γ-巯丙基三甲氧基硅烷(MTS)与凹凸棒土(ATP)表面上的羟基发生脱醇反应,制得表面巯基化的改性粒子ATP-MTS;基于“引发剂转移终止剂”(iniferter)原理,构建巯基-己内酰胺(thiol-caprolactam)双组份引发剂转移终止体系引发苯乙烯活性自由基接枝聚合,制得表面接枝聚苯乙烯的杂化粒子ATP-g-PS.通过红外光谱(FTIR)、X射线光电子能谱(XPS)、热失重分析(TGA)、高分辨率透射电镜(TEM)等方法对杂化粒子ATP-g-PS的结构、组成、形貌进行了表征.结果表明,巯基-己内酰胺双组份引发剂转移终止体系可有效实现苯乙烯的活性接枝聚合,聚苯乙烯成功接枝到改性粒子ATP-MTS表面;模拟实验表明聚合体系呈现活性聚合的特征,单体转化率和PS的分子量均随反应时间的增加而增大,TGA结果表明制得的杂化粒子表面PS接枝率为33.3％.     

聚苯乙烯基N,O-二酰基磺酰羟胺树脂: 一种双酰基转移试剂在合成酰胺库中的应用

用聚苯乙烯基磺酰羟胺树脂1与酰氯2反应合成了聚苯乙烯基N,O-二酰基磺酰羟胺树脂3. 树脂3作为一种新的双酰基转移试剂可与胺4发生酰基转移反应, 合成了含有24个结构类似的酰胺化合物库. 改变酰氯的种类, 结果发现双对硝基苯甲酰树脂3a的活性较高. 双酰基树脂3胺解结果表明, 由脂肪族胺得到的酰胺收率较芳香族胺高. 当解脱试剂同时含有羟基和氨基时, 双酰基树脂3能选择性地在氨基端发生酰基转移, 而羟基端不受影响.     

几种含吡啶双酰胺基双Schiff碱对大肠杆菌的抑菌活性研究

使用LKB 2277热活性监测器测定了大肠杆菌在几种含吡啶双酰胺基双Schiff碱作用下的生热曲线,得到了不同Schiff碱在不同浓度下大肠杆菌生长代谢的生热速率常数k、传代时间、半抑制量浓度。结果发现,含有2,4-二羟基苯甲醛双Schiff碱(Ⅱa和Ⅱg)对大肠杆菌生长代谢的抑制活性要明显大于含其他Schiff碱,而杂环Schiff碱对大肠杆菌抑菌活性顺序为吡啶噻吩呋喃。     

4,4′,4″,4′′′-四羧基酞菁钴(Ⅱ)高分子载体化及其催化硫醇的氧化反应

本文研究了将4,4′,4″,4′″-四羧基酞菁钴(Ⅱ)固载在接枝在硅胶上的高分子碱上,合成出双功能高分子催化剂,并结合2-羟基乙硫醇的氧化,初步探索了其催化活性。 用Co~(60)-γ射线液相共辐照方法在硅胶上接枝聚苯乙烯,以及苯乙烯与2-(或4-)乙烯基吡啶的共聚物。并将接枝在硅胶表面的聚苯乙烯氨甲基化。制得了几种接枝有高分     

Seed polymerization of tetraethyl orthosilicate in the presence of anionic and cationic polystyrene colloidal spheres

Kinetic analyses are made for the seed polymerization of tetraethyl orthosilicate (TEOS) in the presence of anionic and cationic polystyrene colloidal sphere seeds by turbidity and dynamic light-scattering measurements. Transmission-electron microscopy pictures of the spheres formed are also used. The seed polymerization of TEOS is difficult to take place on the surface of anionic polystyrene spheres (44–212 nm in diameter). On the other hand, the reaction proceeds easily on the cationic polystyrene spheres. Hairy and soft surfaces of polystyrene spheres will disturb the seed polymerization. Furthermore, the electrostatic attraction between the anionic hydrolytic products of TEOS molecules and cationic polystyrene spheres plays an important role for the seed polymerization.     

Charge regulation enables anionic hydroxypropyl guar-borate adsorption onto anionic and cationic polystyrene latex

Reported are adsorption isotherms for guar and hydroxypropyl guar (HPG), with and without the presence of borate ions, onto surfactant free anionic polystyrene latex. Guar and HPG formed adsorbed monolayers on the hydrophobic latex. The presence of borate ions converted the nonionic guar and HPG into an anionic polyelectrolyte. However, there was no measurable influence of bound borate ions on the adsorption of guar or HPG onto anionic, hydrophobic latex. To underscore the unusual behavior of HPG-borate, a sample of HPG was oxidized to introduce carboxyl groups, and the adsorption of the carboxylated HPG onto anionic polystyrene was measured. Unlike HPG-borate, oxidized HPG did not adsorb onto negative polystyrene latex at neutral pH because of electrostatic repulsion. To explain the adsorption of negative HPG-borate onto negative latex, we proposed that as HPG-borate segments approach the latex surface, the negative electrostatic potential near the latex surface induces the detachment of the labile borate groups from HPG.     

Solution Properties of Star-Shaped Polystyrenes Having Peripheral Charged Ions

Functionalized polystyrene stars were prepared by copolymerization of polystyryl lithium with divinylbenzene in a mixture of benzene/tetrahydropyran, where the polystyrene arms were prepared by anionic polymerization using [2-[(N,N-dimethylamino)-methyl]phenyl]lithium as the initiator. These functional stars were converted by quaternization with methyl iodide into polystyrene stars having peripheral positive charges. We studied the charge effects on the solution properties of such stars. The hydrodynamic dimension of peripheral charged polystyrene (PS) stars depended strongly on the solubility parameter between PS segments and solvent. Copyright 2000 Academic Press.     

Is latex surface charge an important parameter for foam stabilization?

We describe the facile production of highly stable foams stabilized solely by cationic polystyrene latex particles. Three model polystyrene latexes were synthesized using either a cationic 2,2'-azobis(2-diisobutyramidine) dihydrochloride (AIBA) or an anionic ammonium persulfate (APS) radical initiator: a 724 +/- 81 nm charge-stabilized cationic polystyrene latex [AIBA-PS], an 800 +/- 138 nm sterically stabilized cationic latex prepared using a poly(ethylene glycol) monomethacrylate macromonomer [PEGMA-AIBA-PS], and a 904 +/- 131 nm charge-stabilized anionic polystyrene latex [APS-PS], respectively. The effect of particle surface charge, latex concentration, and solution pH on foam stability was studied in detail. The PEGMA-AIBA-PS latex proved to be the best foam stabilizer even at relatively low latex concentrations (3.0 wt %), with long-term foam stabilities being obtained after drying. The AIBA-PS latex also produced stable foams, albeit only at higher latex concentrations. However, the APS-PS latex proved to be an ineffective foam stabilizer. This is believed to be primarily due to the anionic surface character of this latter latex, which prevents its adsorption at the anionic air-water interface. This hypothesis is supported by the observation that the AIBA-PS latex no longer acts as an effective foam stabilizer above its isoelectric point (pH 7.04). Scanning electron microscopy studies revealed the formation of well-defined latex bilayers within dried foams, which indicates that the wet air bubbles are stabilized by latex monolayers prior to drying. However, little or no long-range ordering of the latex particles was observed on the surface of the bubbles, which is presumably related to the latex polydispersity.     

Synthesis of EPR-g-styrene by anionic coupling technique

Ethylene-propylene rubber (EPR) graft copolymers were prepared successfully by anionic coupling technique between chlorinated EPR (Cl-EPR) and living anionic polystyrene chain.The EPR-g-styrene was characterized by hydrogen nuclear magnetic resonance (~1H NMR) and gel penetration chromatogram (GPC).     

Synthesis of polystyenes with different stereoregularities by anionic polymerization

The stereoregularity of polystyrene prepared by anionic polymerization was determined by means of ¹³C-NMR spectroscopy. The stereoregularity changed with such polymerization conditions as catalyst, solvent, and temperature. Sodium naphthalene as catalyst gave a syndiotactic-rich polystyrene of 66–68% syndiotactic dyads independently of solvent and temperature, while potassium and cesium naphthalenes as catalyst produced polystyrenes with different stereoregularities ranging from syndiotactic-rich to isotactic-rich configurations, depending on solvent and temperature. The mechanism of anionic polymerization which caused the difference in stereoregularity was discussed from the viewpoint of growing ionic species.     

~(13)C-NMR研究聚苯乙烯的序列分布

<正> ~(13)C-NMR谱是目前认为用来研究高聚物序列分布的较好方法。对各种聚苯乙烯的序列分布,前人已做了许多工作,然而无论是对亚甲基(CH_2)或对芳C_1进行分峰,各谱峰的归属及其序列分布统计都没有一致的意见。     

阻滞阴离子聚合的研究进展

介绍了阻滞阴离子聚合引发剂体系近十年的研究现状,详细讨论了几代阻滞引发体系各自的阻滞机理,以及在阴离子聚合制备苯乙烯共聚物树脂中的应用。简单介绍了BASF公司应用阻滞阴离子聚合制备高抗冲聚苯乙烯的应用现状,指出了阻滞阴离子聚合活性可控的优点使其具有更广泛的发展空间。     

Direct visualization of layer-by-layer self-assembled multilayers of organometallic polymers

Direct visualization of organometallic-organic and novel all-organometallic multilayer superlattices prepared by layer-by-layer assembly of cationic/anionic polyferrocenylsilane and anionic polystyrene sulfonate polyelectrolytes using a gold coating/transmission electron microscopy (TEM) technique is reported.     

胶束催化作用下实现聚苯乙烯的氯甲基化

用紫外分光光度法测定了离子型表面活性剂胶束溶液对聚苯乙烯四氯化碳溶液的增溶性能; 用胶束催化法实现了聚苯乙烯的氯甲基化, 用红外光谱法和佛尔哈德法表征了氯甲基化聚苯乙烯的化学结构与组成; 通过比较阴、 阳离子表面活性剂及结构不同的阳离子表面活性剂的催化效果, 探索了胶束催化的作用机理, 考察了表面活性剂结构对催化作用的影响规律. 结果表明, 表面活性剂胶束溶液可增溶聚苯乙烯的四氯化碳溶液, 随着四氯化碳在胶束中的增溶, 聚苯乙烯可转移至表面活性剂的胶束中; 胶束催化是实现聚苯乙烯的氯甲基化的有效途经, 仅用3.35 g/L的十六甲基三甲基溴化铵(CTAB),  于65 ℃， 5 h内即可使聚苯乙烯大分子链中的苯环氯甲基化程度达到37%; 聚苯乙烯与甲醛、 氯化氢的反应过程由亲电取代和亲核取代串联而成, 阳离子表面活性剂比阴离子表面活性剂的催化作用更加有效, 说明亲核取代是慢步骤; 阳离子表面活性剂疏水链越长, 对聚苯乙烯的增溶效果越好, 催化作用越强.