降冰片烯及其衍生物开环易位聚合的研究进展

综述了降冰片烯及其衍生物开环易位聚合的研究进展。分析了ＲＯＭＰ反应特点,催化剂类型对于ＮＥＢ衍生物的ＲＯＭＰ;由于聚合反应发生成ＮＢＥ环上,其衍生物上的取代基赋予了该聚合物特殊的功能,为合成大分子单体提供了一种新方法。还报道了ＮＢＥ的活性聚合研究。     

电纺丝技术制备聚降冰片烯纳米纤维

用静电纺丝技术将相对分子质量不同的无规聚降冰片烯(PNB)以邻二氯苯为溶剂制备出了微米级和近纳米级的聚降冰片烯纤维,并且研究讨论了相对分子质量、溶液浓度、纺丝电压和纺丝距离等因素对纤维直径的影响。随着聚降冰片烯溶液浓度增加,溶液的表面张力减小,相对分子量最大的PNB得到的纤维直径较大。     

原子转移自由基聚合法制备聚合物刷

介绍了原子转移自由基聚合法(ATRP)制备聚合物刷(平面刷、球形刷和分子刷)的研究进展及应用前景.聚合物刷子的奇异构象使其具有许多新奇的性质和潜在的应用前景.ATRP是制备具有可控结构的聚合物以及有机/无机杂化材料的一种较好的方法.通过ATRP制备聚合物刷,可以有效地改变聚合物刷的组成和聚合度,从而改变聚合物刷的表面性质,设计出具有新型结构及性能的材料.     

原子转移自由基聚合制备ABA型嵌段共聚物

以α，α’－二溴代二甲苯为引发剂，CuBr/2,2‘－联吡啶为催化体系，制备了双溴端基的分子量分布窄的聚苯乙烯（MWD＝1．21）。再以此作为大分子引发剂，实现了甲基丙烯酸甲酯的原子转移自由基聚合，制得了分子量可控且分子量分布窄的ABA型嵌段共聚物，即聚甲基丙烯酸甲酯－b－聚苯乙烯－b－聚甲基丙烯酸甲酯。     

原子转移自由基聚合的最新研究进展

介绍了关于原子转移自由基聚合(ATRP) 引发-活化-失活过程的最新研究进展,包括RATRP 体系克服了常规ATRP 体系中低价态过渡金属催化剂容易氧化的问题,AGET ATRP 体系显著降低了过渡金属化合物的用量,ARGET ATRP体系中残存的过渡金属催化剂仅为(1～50)×10-6, 很多情况下不需要进行后处理,使其适合工业化生产成为可能.同时介绍了ATRP在表面接枝上的应用,表面引发ATRP反应能改善材料的表面特性,同时具有接枝链分子量及分布可控和高接枝率的优点,使其在很多方面都获得了广泛的应用,包括使材料表面图案化、提高材料表面的生物相容性、制备梳型的聚合物刷以及在纳米磁铁矿和真丝表面引发的ATRP反应.     

降冰片烯及其衍生物开环易位聚合的研究进展

环烯烃开环易位聚合(ROMP)是指在金属催化剂存在下,环烯烃中的碳碳双键断裂并重新结合形成新的分子,得到的聚合物中留有不饱和双键,具有活性聚合的特点。ROMP是改造碳碳双键最有效的手段之一,极具特色且广泛应用于高分子材料与有机分子的合成。关于环烯烃ROMP研究早在20世纪50年代就已开始,当时的研究主要集中在以Ti、Re、W、Mo等过渡金属配合物组成的Ziegler-Natta催化体系引发环烯烃ROMP。20世纪80年代中期以后,研究则以亚烷基类或卡宾型类催化剂为主,其引发环烯烃ROMP的机理更加清晰。随着结构明确、稳定高效的环烯烃ROMP催化剂的开发与完善,该领域的研究焦点开始转向环烯烃ROMP适用单体的拓展以及所得聚合物的应用。在环烯烃ROMP研究中,降冰片烯及其衍生物是研究最多和应用最广的一类单体,这是因为它们的反应活性较高,来源丰富,价格也不昂贵。除研究拓展ROMP适用单体外,研究者主要从降冰片烯基单体的空间位阻、化学构型、侧基极性以及与其他环烯烃或降冰片烯基单体共聚改性等方面不断进行尝试,同时充分发挥环烯烃ROMP优势,与其他聚合方法联用,不断改善所得聚合物的性能并将其应用于不同研究领域。降冰片烯及其衍生物ROMP在阻燃材料、交换膜、纳米材料、生物医药等领域已取得一系列研究成果,其中在阻燃材料领域研究最早且许多产品已经工业化。在交换膜领域,由于降冰片烯基聚合物膜的热稳定性、耐酸碱性和电导率均较好,目前的研究主要是探索如何在燃料电池中获得应用。纳米材料是近年来最热门的研究领域之一,降冰片烯基纳米金属聚合物材料和纳米磁性聚合物材料等已有初步应用。在生物医药领域,降冰片烯及其衍生物极具发展前景,目前的研究主要集中在药物传输材料,已有初步的研究成果,但要实现工业化尚待进一步研究。此外,基于降冰片烯及其衍生物的接枝聚合物、嵌段聚合物、液晶聚合物、导电聚合物等也获得人们越来越多的关注。本文简要介绍了降冰片烯及其衍生物ROMP的反应机理,以及ROMP催化剂从多组分到钼、钨系再到钌系等几个发展阶段,详细综述了降冰片烯及其衍生物ROMP在上述若干领域的研究进展,并在此基础上简要探讨了今后研究与开发应用的新方向。     

原子转移自由基聚合在生物材料中的应用

生物材料表面改性以及具有特定结构与功能的先进生物材料的合成始终是生物材料研究的核心课题.原子转移自由基聚合( ATRP)是一种新型自由基聚合,在生物材料表面改性以及新型生物材料合成方面具有巨大的应用前景.利用ATRP技术可以提高生物材料表面生物相容性、生物适应性以及生物功能性,如提高材料表面的抗生物污染性、血液相容性、细胞相容性以及抗菌性能等;同时,ATRP也可用于合成新型生物医用高分子材料,如两亲性高分子、纳米胶束、智能水凝胶以及一些具有特殊结构的高分子(包括星型、超支化、梳型高分子等).ATRP技术与点击化学结合,可形成新的生物活性表面或者合成新的生物材料,可望产生更多的功能化的材料表面与生物材料.     

原子转移自由基聚合及催化剂负载化研究进展

原子转移自由基聚合(ATRP)具有可控聚合的典型特征,自1995年来受到高分子界的广泛关注。介绍了ATRP在应用方面的研究进展;传统ATRP由于存在催化剂脱除困难等问题,制约了其工业化进程。介绍了易分离的负载型催化剂的近期研究进展。     

原子转移自由基聚合的催化剂再生机理与聚合可控

催化剂再生即向反应体系中加入各种不同形式的＂还原剂＂保证催化剂的活性使聚合反应得以进行。文中介绍了几种原子转移自由基聚合（ATRP）催化剂再生的引发体系,包括电子转移产生催化剂引发ATRP（AGET ATRP）,连续活化剂再生引发剂引发ATRP（ICAR ATRP）,单电子转移活性自由基聚合（SET LRP）,过量单体...     

原子转移自由基聚合(ATRP)制备聚合物刷的研究进展

从聚合物刷的概念和ATRP技术的提出入手,概述了聚合物刷的基本理论、合成方法及应用,并着重介绍了ATRP法制备聚合物刷方面的研究进展.     

Synthesis of thermoresponsive silica nanoparticle/PNIPAM hybrids by aqueous surface-initiated atom transfer radical polymerization

This paper described the synthesis of a novel kind of thermoresponsive silica nanoparticle/PNIPAM hybrids by aqueous surface-initiated atom transfer radical polymerization at room temperature. These resulting hybrid particles were characterized by FT-IR, XPS, TEM, TGA and variable temperature DLS which indicated that they owned both core/shell structures and thermoresponsiveness.     

ATRP法制备聚甲基丙烯酸2,2,2-三氟乙酯-b-聚苯乙烯嵌段共聚物的研究

用α-溴代丙酸乙酯(EPN-B)/氯化亚铜(CuCl)/联二吡啶(bpy)作为ATRP催化引发体系,环己酮为溶剂,进行甲基丙烯酸2,2,2-三氟乙酯(TFEMA)的原子转移自由基聚合(ATRP),得到单分散PTFEMA-X预聚体.并以此预聚体为大分子引发剂引发苯乙烯聚合,得到分子质量可控、分子质量分布窄的聚甲基丙烯酸2,2,2-三氟乙酯-b-聚苯乙烯嵌段共聚物,考察了大分子引发剂的分子质量、配位剂等对聚合过程的影响.并用1H-NMR、FTIP、GPC、DSC等时产物的结构与性能进行了表征.     

Detection of DNA point mutation by atom transfer radical polymerization

We report here a new DNA detection method in which polymer growth in atom transfer radical polymerization (ATRP) is used as a means to amplify detection signals. In this method, DNA hybridization and ligation reactions led to the attachment of ATRP initiators on a solid surface where specific DNA sequences were located. These initiators subsequently triggered the growth of poly(hydroxyethyl methacrylate) (PHEMA) at the end of immobilized DNA molecules and formed polymer brushes. The formation of PHEMA altered substrate opacity, rendering the corresponding spots readily distinguishable to the naked eye. A second ATRP reaction to form branched polymers on the surface drastically improved the visibility of DNA hybridization and significantly shortened the detection time. The resulting polymer film was characterized using infrared spectroscopy, ellipsometry, contact angle measurements, and atomic force microscopy. Direct visualization of 1 fmol of target DNA molecules of interest was demonstrated. A proof-of-principle experiment to detect DNA point mutation was conducted. The perfectly matched DNA targets were distinctively differentiated from those with mutations. The demonstrated capability to detect DNA mutation with direct visualization laid the groundwork for the future development of detector-free testing kits in single-nucleotide polymorphism screenings.     

电子转移活化再生催化剂原子转移自由基聚合(ARGET ATRP)的研究进展

ARGET ATRP可将反应中催化剂用量降至ppm级,是目前最具工业化应用前景的原子转移自由基聚合(ATRP)之一。综述了ARGET ATRP的反应机理、引发剂、催化体系、还原剂、反应条件及其在污水处理、纤维素改性、燃料电池方面的应用,并对ARGET ATRP技术的前景进行了展望。     

Preparation of an ion-exchange chromatographic support by a "grafting from" strategy based on atom transfer radical polymerization

A new "grafting from" strategy based on surface-initiated atom transfer radical polymerization (ATRP) was first used for the preparation of a polymer-based ion-exchange support for HPLC. The most important property of the proposed method is to be applicable for the synthesis of any type of ion exchanger in both the strong and the weak forms. Monodisperse, porous poly(glycidyl methacrylate-co-ethylene dimethacrylate), poly(GMA-co-EDM) particles 5.8 mum in size were synthesized by "modified seeded polymerization". Poly(dihydroxypropyl methacrylate-co-ethylene dimethacrylate), poly(DHPM-co-EDM) particles were then obtained by the acidic hydrolysis of poly(GMA-co-EDM) particles. The ATRP initiator, 3-(2-bromoisobutyramido)propyl(triethoxy)silane was covalently attached onto poly(DHPM-co-EDM) particles via the reaction between triethoxysilane and diol groups. In the next stage, the selected monomer carrying strong cation exchanger groups, 3-sulfopropyl methacrylate (SPM), was polymerized on the initiator-immobilized particles via surface-initiated ATRP. The degree of polymerization of SPM (i.e., length of polyionic ligand) on the particles was precisely controlled by adjusting ATRP conditions. Poly(SPM)-grafted poly(DHPM-co-EDM) particles obtained with different ATRP formulations were tried as chromatographic packing in the separation of proteins by ion-exchange chromatography. The proteins were successfully separated with higher column yields with respect to the previously proposed materials. The plate heights between 100 and 150 mum were achieved with the column packed with the particles carrying the shortest poly(SPM) chains. The plate height showed no significant increase with increasing flow rate in the range of 0.5-16 cm/min.     

ATRP表面接枝在功能膜制备中的应用

ATRP表面引发接枝聚合是功能膜制备中一个重要而有效的方法.近年来,随着原子转移自由基聚合(ATRP)研究的快速发展,将ATRP应用于功能膜制备的研究已取得了显著的进展.详细介绍了在膜表面固定ATRP引发剂的方法及将ATRP表面接枝法应用于制备抗污染能力强,抗菌性好,环境响应迅速等多种功能性膜方面的研究进展情况.     

Synthesis and self-assembly of pH-responsive chitosan graft copolymer by the combination of atom transfer radical polymerization and click chemistry

Amphiphilic chitosan-graft-poly(2-(N,N-diethylamino)ethyl methacrylate)-block-poly(ethylene oxide) (CS-g-(PDEAEMA-b-PEO)) copolymer was synthesized by the combination of atom transfer radical polymerization (ATRP) and click chemistry. The copolymer was characterized by ¹H NMR spectrum. The self-assembly and pH-responsive properties of CS copolymer were investigated by TEM, DLS, and transmittance in water. The micelle sizes can be adjusted through the alteration of the pH values of solutions. The presence of PEO segments can improve the hydrophilicity of the copolymer and avoid the excessive aggregation of the micelles. CS-g-(PDEAEMA-b-PEO) copolymer has both the unique properties of PDEAEMA-b-PEO and chitosan, and will have the potential applications in biomedical field.     

"Hairy" single-walled carbon nanotubes prepared by atom transfer radical polymerization

"Hairy nano-objects" are hybrid nanostructures comprising a core surrounded by a "hairlike" corona of flexible polymer chains, the role of which is typically to improve the solubility of the core material or to improve its dispersability and adhesion in other polymer matrices. Both aspects could be particularly useful with carbon nanotubes, especially in their applications as reinforcing agents. The controlled synthesis of hairy carbon nanotubes is accomplished by chemical modification with 2-bromopropionate followed by extension with poly(n-butyl acrylate) through atom transfer radical polymerization. The obtained hairy nanotubes are visualized at nearly molecular resolution with tapping-mode atomic force microscopy, providing insight into the uniformity of grafted chain lengths and grafting density. The grafting densities vary from approximately 1.0-10.0 chains nm(-1) along the nanotubes. Such a wide range of grafting density may indicate some chemical heterogeneity along and between the nanotubes; it may be also an indication of the challenges associated with carrying out chemical modification of nano-objects having high tendency to aggregate.     

Facilely dispersible magnetic nanoparticles prepared by a surface-initiated atom transfer radical polymerization

Facilely dispersible magnetic nanoparticles (Fe₃O₄) prepared by a surface-initiated atom transfer radical polymerization (ATRP) of poly (ethylene glycol) methyl ether monomethacrylate (PEGMA) are reported. The initiator of 2-bromoisobutyrate (BIB) for ATRP was immobilized onto the surface of Fe₃O₄ nanoparticles by the reaction between 2-bromoisobutyryl bromide (BIBB) and the hydroxyl group on the nanoparticles. The results indicated that the poly(poly(ethylene glycol) monomethacrylate) (PPEGMA) was successfully grafted onto the surface of the magnetic nanoparticles. The core-shell nanoparticles with particle size of ≈ 20 nm in water (about 20 mg/mL) are facilely dispersible and can be easily captured by a magnet with magnetic field of 2000 G.