可控/活性聚合在无机粒子表面接枝研究进展

介绍了一些主要的可控／活性自由基聚合法,包括氮氧调解自由基聚合法（NMRP）、原子转移自由基聚合法（ATRP）、可逆加成断裂链转移聚合法（RAFT）在粒子表面接枝聚合形成无机纳米粒子／聚合物的壳核结构,达到了对粒子改性的目的。并提出了一些目前研究中存在的问题,对可控／活性聚合应用的发展进行了展望。     

基于RAFT聚合策略合成功能化聚烯烃嵌段聚合物的研究进展

首先介绍了可逆加成-断裂链转移聚合（RAFT）的聚合机理及其常用的RAFT试剂,并与其它两种活性可控自由基聚合[氮氧化合物媒介的自由基聚合（NMP）和原子转移自由基聚合（ATRP）]进行了简单的优缺点对比。其次,介绍了近些年在基于RAFT聚合制备功能化聚烯烃嵌段聚合物研究中取得的进展,重点综述了制备功能化聚烯烃嵌段聚合物时所采用的6种方法,包括①烯烃配位聚合与RAFT聚合相结合;②阴离子聚合与RAFT聚合相结合;③阳离子聚合与RAFT聚合相结合;④Click反应与RAFT聚合相结合;⑤开环聚合与RAFT聚合相结合;⑥叶立德活性聚合与RAFT聚合相结合。最后,对基于RAFT聚合策略设计合成功能化聚烯烃嵌段聚合物的研究前景与实际应用进行了展望。     

ATRP与其他反应技术联用合成聚合物分子刷的研究进展

原子转移自由基聚合(ATRP)作为一种可控/"活性"聚合技术,与其他反应技术联用可以有效地合成具有不同结构与性能的聚合物分子刷。综述了ATRP与点击反应、开环聚合(ROP)、可逆加成-断裂链转移(RAFT)聚合联用合成聚合物分子刷的研究进展。     

甲基丙烯酸酯/二甲基丙烯酸酯自由基共聚合体系中的自加速和凝胶行为

对甲基丙烯酸聚乙二醇单醚酯/二甲基丙烯酸聚乙二醇酯共聚体系分别实施常规自由基聚合（FRP）,原子转移自由基聚合（ATRP）和可逆加成-断裂链转移（RAFT）自由基聚合,通过观察聚合速率、双键转化率、凝胶点以及交联网络的发展,比较FRP、ATRP和RAFT共聚合体系的反应动力学和交联行为。3个聚合体系均出现了自加速现象,ATRP体系的自加速由扩散控制的自由基脱活造成,RAFT体系的自加速来自于扩散控制的自由基加成。在ATRP和RAFT交联体系中,初级链的缓慢增长和充分松弛减少了分子内环化,抑制了微凝胶形成,因此其凝胶点远低于FRP体系。ATRP和RAFT交联网络通过凝胶自由基与单体加成以及支化链的结合而不断发展,导致凝胶含量和交联网络密度随转化率不断增大。     

原子转移自由基聚合原理及应用

介绍了有关原子转移自由基聚合(ATRP)的聚合原理。最新研究表明:应用ATRP法进行聚合反应可以制备接枝聚合物、嵌段聚合物、超支化聚合物和其它有机/无机混合型聚合物等。ATRP在高分子聚合反应领域具有十分广阔的应用前景。     

树核星形聚合物合成的研究进展

简介了合成树核星形聚合物常用的树状分子,综述了近年来原子转移自由基聚合(ATRP)、可逆加成-断裂链转移聚合(RAFT)、开环聚合(ROP)、阴离子聚合和光引发自由基聚合在合成树核星形聚合物中的应用。     

两亲性嵌段共聚物的合成及其自组装行为

采用原子转移自由基聚合（ATRP）方法合成了两亲性嵌段共聚物PSt-b-PAA。用1H NMR和GPC等手段对活性聚合进行了确认,对嵌段共聚物的结构进行了表征。两亲性嵌段共聚物在离子液体1-丁基-3-甲基咪唑六氟磷酸盐（[BM IM][PF6]）中形成胶束溶液。用透射电子显微镜（TEM）观察聚合物在离子液体中形成胶束的纳米结构。当疏水链长固定时,胶束的自组装形状主要依赖于亲水链的长度。两亲性共聚物在离子液体中可自组装成可控制结构的纳米胶束,这种纳米胶束可应用在很多领域。     

结构可控含氟共聚物的合成及其应用研究新进展

近年来,含氟聚合物以其优异的耐热性、耐氧化性、耐候性、耐腐蚀性以及低介电常数、低表面能等特点,在疏水材料、抗污材料、表面活性剂、造影剂等领域具有广泛的应用前景,受到研究者的密切关注,各种拓扑结构的含氟共聚物被设计合成出来并在相关领域得到应用。本文首先简要介绍了含氟聚合物的性质和研究现状,然后详细叙述了可逆加成-断裂链转移聚合（RAFT）、原子转移自由基聚合（ATRP）、碘转移自由基聚合（ITP）、单电子转移活性聚合（SET-LRP）、氮氧稳定自由基聚合（NMP）以及活性阴离子聚合（LAP）等聚合方法在结构可控含氟共聚物合成中的研究新进展,并对其聚合机理、优缺点以及所得共聚物的性质和应用进行了总结,最后对结构可控含氟共聚物的设计、合成及实际应用前景进行了展望,提出发展绿色环保功能性含氟聚合物将是未来的主要研究热点。     

采用可逆加成-断裂链转移化学剪切法制备细乳液和纳米胶囊

以含羧基的双亲性可逆加成-断裂链转移(RAFT)试剂为乳液稳定剂前体,探索化学剪切法与双亲性RAFT试剂相结合制备细乳液并进而制备纳米胶囊的可行性。研究发现,通过化学剪切法可制备液滴大小为亚微米的细乳液,乳化效果与双亲性RAFT试剂的结构密切相关。在本研究范围内,以poly(AAm-b-Stn)RAFT和poly(MAAm-co-Stn)RAFT为试剂的乳化效果较好,采用这两种RAFT试剂,经细乳液界面聚合均可得到核壳结构的纳米胶囊粒子,前者聚合过程的稳定性较好。     

原子转移自由基聚合反应机理及其应用

概述了有关原子转移自由基聚合(ATRP)的反应机理.研究成果表明,应用ATRP法进行聚合反应可以制备窄分子量分布的聚合物、嵌段共聚物、接技聚合物、无规共聚物、星型聚合物等.ATRP在聚合反应领域具有非常广阔的应用前景.     

Cyclic polyaniline nanostructures from aqueous/organic interfacial polymerization induced by polyacrylic acid

Cyclic nanostructural polyanilines have been synthesized by means of a simple modified aqueous/organic interfacial polymerization with the aid of polyacrylic acid, and yet only nanofiber nanostructural polyanilines were obtained by conventional interfacial polymerization in the presence of polyacrylic acid. These nanostructures were characterized using TEM, X-ray diffraction and UV-vis. The cyclic polyaniline nanostructures were formed by severe secondary overgrowth through the electrostatic interaction between aniline/oligoaniline and polyacrylic acid chains. The average diameter of the obtained cyclic-structure was ca. 400 nm and its conductivity was 1.06 S/cm.     

硅氟两亲聚合物在柴油/水体系中的分水效能及机理

对4种含氟链段聚合度不同的硅氟聚合物在柴油/水体系中的分水效能进行了评价,并通过界面张力和界面黏弹性研究了其分水机理。结果表明,随着含氟链段聚合度的增加,其油水分离时间先减小后增大。含氟单体平均聚合度为16的聚合物质量浓度为0.2g/L时,在23s内实现柴油/水的完全分离。界面张力不是影响分水效能的主要因素,该类聚合物主要通过降低界面膜黏弹性实现有效分水。     

Preparation and Performance of a Novel Water‐Soluble Cationic Polymer Containing β‐Cyclodextrin

Allyl‐β‐cyclodextrin is utilized to react with dimethyl diallyl ammonium chloride and acrylamide to synthesize a novel water‐soluble cationic polymer by redox free‐radical polymerization. The optimum polymerization conditions are determined by the single‐variable method, while the structure is characterized by Fourier transform infrared and scanning electron microscopy. In rheological experiments the polymer demonstrates superior properties compared to polyacrylamide. Interfacial tension and adsorption experiments prove the excellent performance of the polymer which can effectively decrease the interfacial tension and reduce the surfactant loss caused by stratum absorption in the process of polymer/surfactant flooding, thus indicating the potential application of the polymer for enhancing oil recovery.     

Interfacial tension of demixed polymer solutions near the critical temperature: polystyrene + methylcyclohexane

Interfacial tension between demixed solutions of polystyrene + methylcyclohexane has been measured near the critical temperature as a function of temperature using polystyrenes with molecular weights 9000 ～ 1.26 × 10⁶. The critical exponent for the interfacial tension was determined to be about 1.30 for the lower molecular weight systems. However, for higher molecular weights the exponent could not be obtained because the system departed from critical behaviour. Magnitudes of the interfacial tension were proportional to about N^?0.44, where N is the polymerization index. Experimental results were compared with the recently-proposed theories and found to be in qualitative agreement. The tricritical theory of polymer solutions was also compared with the experimental results.     

Realizing the enhancement of interfacial interaction in semicrystalline polymer/filler composites via interfacial crystallization

Polymer/filler composites have been widely used in various areas. One of the keys to achieve the high performance of these composites is good interfacial interaction between polymer matrix and filler. As a relatively new approach, the possibility to enhance polymer/filler interfacial interaction via crystallization of polymer on the surface of fillers, i.e., interfacial crystallization, is summarized and discussed in this paper. Interfacial crystallization has attracted tremendous interest in the past several decades, and some unique hybrid crystalline structures have been observed, including hybrid shish-kebab and hybrid shish-calabash structures in which the filler served as the shish and crystalline polymer as the kebab/calabash. Thus, the manipulation of the interfacial crystallization architecture offers a potential highly effective route to achieve strong polymer/filler interaction. This review is based on the latest development of interfacial crystallization in polymer/filler composites and will be organized as follows. The structural/morphological features of various interfacial crystallization fashions are described first. Subsequently, various influences on the final structure/morphology of hybrid crystallization and the nucleation and/or growth mechanisms of crystallization behaviors at polymer/filler interface are reviewed. Then recent studies on interfacial crystallization induced interfacial enhancement ascertained by different research methodologies are addressed, including a comparative analysis to highlight the positive role of interfacial crystallization on the resultant mechanical reinforcement. Finally, a conclusion, including future perspectives, is presented.     

In-situ polymerization of styrene in AAO nanocavities

One of the most promising aspects of the anodic aluminium oxide (AAO) template is the ability to generate a variety of different hierarchical one-dimensional (1D) polymer morphologies with structural definition on the nanometric scale. In-situ polymerization of monomers in reduced space of porous AAO template nanocavities can give rise to the direct production of versatile polymer nanostructures. In this work, porous AAO devices of 35 nm of diameter have been obtained by a two-step electrochemical anodization process and used as a nanoreactor to study the radical polymerization kinetics of styrene (St) in confinement and the results compared to those of polymerization in bulk. SEM morphological study has been conducted to establish the final structure of obtained polymer nanostructures. Confocal Raman microscopy has been performed to study the formation of the polymer through the AAO cavities as a function of time and with this methodology it has been possible to establish the monomer conversion for styrenic polymerization in AAO devices. Polystyrene obtained in the nanoreactor was characterized by SEC, NMR, TGA and DSC and the properties compared with those of bulk polymer. It was found that both the average molecular weights and polydispersity index of nanostructured polymer are lower than those obtained for bulk polymer. NMR studies have shown that the use of a reactor with nanometric size dimensions gave the obtained polystyrene greater stereospecificity than that obtained in bulk. Thermal stability and glass transition temperature (T_g) values are higher for nanostructured than bulk polymers. Moreover, the methodology proposed in this work, using AAO nanocavities as nanoreactors for polymerization reaction, can be generalized and applied to obtain polymer nanostructures of very different chemical nature and morphology by choosing the appropriate monomer or monomer reactants and by tailoring the dimension of AAO cylindrical nanocavities, that is, diameter from 20 to 400 nm and length from a few to hundreds of microns.     

界面聚合技术制备分离膜的研究进展

界面聚合技术具有许多优良性能，如反应条件温和、可控性强、可以实现自封闭和自终止等，被广泛应用于分离膜制备中。本文阐述了界面聚合技术的原理，详细介绍了界面聚合在膜分离中的应用情况，包括纳滤膜、反渗透膜和气体分离膜，并综述了界面聚合技术在微胶囊、导电聚合物、纤维材料等方面的应用现状。最后，对界面聚合技术制备分离膜的研究前景进行了展望。     

Plasma etching and plasma polymerization coating of carbon fibers. Part 2. Characterization of plasma polymer coated carbon fibers

Unsized AS-4 carbon fibers were subjected to RF plasma etching and/or plasma polymerization coating in order to enhance their adhesion to vinyl ester resin. Ar, N₂ and O₂ were utilized for plasma etching, and acetylene, butadiene and acrylonitrile were used for plasma polymerization coating. Etching and coating conditions were optimized in terms of plasma power, treatment time, and gas (or monomer) pressure by measuring the interfacial adhesion strength. Interfacial adhesion was evaluated using micro-droplet specimens prepared with vinyl ester resin and plasma etched and/or plasma polymer coated carbon fibers. Surface modified fibers were characterized by SEM, XPS, FT-IR, α-Step, dynamic contact angle analyzer (DCA) and tensile strength measurements. Interfacial adhesion between plasma etched and/or plasma polymer coated carbon fibers and vinyl ester resin was reported previously (Part 1), and characterization results are discussed is this paper (Part 2). Gas plasma etching resulted in preferential etching of the fiber surface along the draw direction and decreased the tensile strength, while plasma polymer coatings altered neither the surface topography of fibers nor the tensile strength. Water contact angle decreased with plasma etching, as well as with acrylonitrile and acetylene plasma polymer coatings, but did not change with butadiene plasma polymer coating. FT-IR and XPS analyses revealed the presence of functional groups in plasma polymer coatings.     

Modeling of interfacial modification effects on thermal conductivity of carbon nanotube composites

The effect of functionalization of carbon nanotubes on the thermal conductivity of nanocomposites has been studied using a multi-scale modeling approach. These results predict that grafting linear hydrocarbon chains to the surface of a single wall carbon nanotube with covalent chemical bonds should result in a significant increase in the thermal conductivity of these nanocomposites. This is due to the decrease in the interfacial thermal (Kapitza) resistance between the single wall carbon nanotube and the surrounding polymer matrix upon chemical functionalization. The nanocomposites studied here consist of single wall carbon nanotubes in a bulk poly(ethylene vinyl acetate) matrix. The nanotubes are functionalized by end-grafting linear hydrocarbon chains of varying length to the surface of the nanotube. The effect which this functionalization has on the interfacial thermal resistance is studied by molecular dynamics simulation. Interfacial thermal resistance values are calculated for a range of chemical grafting densities and with several chain lengths. These results are subsequently used in an analytical model to predict the resulting effect on the bulk thermal conductivity of the nanocomposite.     

Interfacial polymerization of morphologically modified polyaniline: from hollow microspheres to nanowires

BACKGROUND: Polyaniline (PANI) has attracted much attention in many fields due to its chemical and physical properties, and different nanostructures of PANI changing from one‐dimensional to three‐dimensional have been obtained. By changing the concentration of cetyltrimethylammonium bromide (CTAB), the morphology of hydrochloric acid‐doped polyaniline could be changed from one‐dimensional nanoneedles or nanowires with a network structure (50–100 nm in diameter) to three‐dimensional hollow microspheres (ca 400 nm in outer diameter) via combining interfacial polymerization and self‐assembly process. RESULTS These different nanostructures of PANI were proved using scanning electron and transmission electron microscopies. A plausible mechanism of the formation of the changeable nanostructures of PANI may be different from that of interfacial polymerization without surfactant or a traditional homogenous reaction system using CTAB as surfactant. CONCLUSION The results obtained from Fourier transform infrared spectrometry, X‐ray diffraction and the four‐probe method showed that the molecular structure of PANI does not change with increasing CTAB concentration, but crystallinity and conductivity of PANI increase with surfactant concentration. Copyright © 2007 Society of Chemical Industry