非共价键胶束—聚合物自组装的新途径

纳米材料;高分子;聚合物;非共价键胶束—聚合物自组装的新途径     

聚合物科学进展

本文对2011~2013年我国高分子科学重要研究进展进行了综述。全文分为高分子化学、响应性高分子、高分子物理、高分子组装、超分子聚合物、光电功能聚合物、生物医用高分子、石墨烯/聚合物复合体系、聚合物杂化体系和高分子工程等10部分。近年我国内地学者发表的高分子领域研究论文总量跃居世界第一,论文引用数跃居第二,在诸多分支领域中学科发展水平大幅提高,达到或接近国际水平的研究成果快速增多,国际影响力逐年提高。我国高分子学者通过基础研究,为高分子工业技术水平提升和创新也做出了许多贡献。本文还对本学科前沿、发展趋势进行了介绍与展望。文中共引用了227篇参考文献。     

2005年我国内地学者高分子科学基础研究进展概述

简要介绍了2005年度我国内地学者在高分子主要前沿领域基础研究的进展，涉及的领域主要包括特殊构筑高分子的合成、高分子结构表征、光电功能高分子、高分子自组装与超分子聚合物、高分子微纳结构与纳米复合体系、类细胞膜融合分裂的实时观测和生物医用高分子等。     

含环糊精链节的拓扑高分子

星形、超支化、树枝状、刷状等具有支化拓扑结构的高分子通常具有不同于直链结构高分子的优异性能。将有客体包合功能的环糊精与其结合构筑环糊精拓扑高分子体系,有望在分子识别、基因传输、药控释放等领域得到应用。本文根据高分子拓扑形态的不同,从星形、超支化、树枝状以及其他拓扑形态环糊精聚合物的合成及自组装构筑等方面进行了总结和评述,并在此基础上展望了基于环糊精的拓扑高分子的研究方向和发展趋势。     

基于环糊精的高度支化聚合物*

环糊精（CD）与高度支化聚合物都存在空腔结构,若将两者结合起来可构筑出含有两种不同疏水空腔且具有特异物理化学功能的高分子体系,并有望在分子包合与识别、药物控释、基因传输等领域得到新的应用。本文根据高度支化聚合物与环糊精结合方式的不同,从以环糊精为核的高度支化聚合物、外端悬挂环糊精的高度支化聚合物、高度支化聚合物的结构单元与环糊精包合、环糊精与客体分子包合后自组装成高度支化聚合物,以及用功能化的环糊精单体合成超支化聚合物等5个方面对其研究进展进行了总结和评述,并在此基础上展望了该类聚合物的研究方向和发展趋势。     

动态硼酸酯键管控邻苯二酚基团与功能黏附性高分子设计

“黏附”是一种普遍存在的多尺度相互作用,其实质是界面处化学键、氢键或范德华力等的形成.近年来,在贻贝仿生的基础上将黏性因子邻苯二酚基团嵌入到动态硼酸酯聚合物中,成为了功能黏附性高分子的重要发展方向.本专论从分子黏附、微/纳表面黏附和宏观表面黏附3个尺度,介绍硼酸酯键管控邻苯二酚基团在高分子材料功能化方面的研究进展.分子黏附,主要讨论硼酸酯聚合物中邻苯二酚基团与分子或离子相互作用规律及其对材料形貌和刺激响应性能的调控;微/纳表面黏附,论述硼酸酯聚合物体系超分子驱动力和组装机制,介绍其在微/纳材料功能化改性方面的研究进展;宏观表面黏附,讨论硼酸酯键管控邻苯二酚基团与黏附性能调控的关联规律,介绍硼酸酯聚合物功能黏附材料在宏观组装、攀爬机器人领域的应用.最后,从新型硼酸酯聚合物设计、动态键精准管控和器件化应用的角度,对该领域未来前景和发展趋势做出了展望.     

粘度比对刚性链高分子与柔性链高分子共混物微结构的影响

粘度比对刚性链高分子与柔性链高分子共混物微结构的影响何嘉松,卜文胜,张洪志,许向青（中国科学院化学研究所,北京,１０００８０）（化工部北京化工研究院,北京,１０００１３）关键词高分子共混物,热致液晶聚合物,聚合物加工影响柔性链高分子与柔性链高分子共混...     

“高分子物理学”中的基本概念

"高分子物理学"具有基本概念多、理论多的特点,本文沿着"高分子物理学"的主线,按照"聚合物结构-分子运动-性能"的基本框架,从聚合物的链结构、聚合物的凝聚态结构、高分子溶液、黏弹性、聚合物的分子运动和转变、聚合物的极限力学性质等方面,阐明所涉及的重要基本概念的含义和作用,目的是使学生在明晰基本概念的基础上,掌握"高分子物理学"中的公式和基础理论,系统整体化学习高分子物理这门基础理论课程。     

关于高分子物理教学的思考：系带分子——结晶聚合物结构与性能的纽带

结晶聚合物涉及大量复杂的概念和理论知识,是高分子物理教学的重难点内容之一。其中“系带分子”作为结晶聚合物中的重要组成部分,不仅仅是联结晶体与晶体的系带,也是理解结晶聚合物结构与性能的“系带”。本文提出以结晶聚合物中的“系带分子”为线索,对结晶聚合物涉及的相关知识进行串连和梳理,阐述聚合物的晶体结构模型以及结晶聚合物结构与性能的关系,帮助学生理解和记忆结晶聚合物相关知识的同时,建立对结晶高分子结构与性能对应关系的理解,进而形成在学习高分子相关知识时从结构到性能的思维逻辑。同时也通过鼓励学生自主查阅文献,学习和总结学术上关于结晶聚合物研究的历史沿革和最新进展的形式,进一步加深学生对课堂知识的掌握,锻炼学生们独立思考的能力。     

刺激响应星形聚合物的合成及其药物可控释放研究

星形聚合物是从一个枝化点呈放射形连接出三条及三条以上线形链的一类具有特殊拓扑结构的聚合物.与组成和分子量相同的线形聚合物相比,星形聚合物具有明确的结构、较窄的分子量分布、较低的黏度和多功能性,已成为高分子领域的研究热点之一.引入刺激响应基团的刺激响应星形聚合物具有随外界环境变化而发生敏感调整的结构特征,并在药物可控释放方面具有重要的应用价值,受到广泛关注.本文总结现阶段刺激响应星形聚合物应用于药物可控释放方面的最新研究成果,主要根据不同的环境刺激信号进行分类,分别介绍了pH、温度、双重或多重刺激响应星形聚合物的合成方法,分析其在溶液中的自组装行为、刺激响应情况和药物可控释放功能,并对相关聚合物体系的改进和发展进行展望.     

高分子科学的近期发展趋势与若干前沿

分别按高分子合成化学、高分子科学与生命科学的交叉研究、光电磁活性功能高分子、超分子组装与高级有序结构构筑、高分子物理与高分子物理化学、高分子加工新原理、新方法等,对高分子科学近期主要发展趋势和若干前沿方向做一综述.     

Recent progress in EPR study of spin labeled polymers and spin probed polymer systems

The EPR technique is commonly used for the detection and characterization of paramagnetic centers in chemical science. This method can provides a lot of information, such as identity, structure, dynamics, interaction, orientation, glass transition temperature, adsorption behavior, functionality, phase behavior, nano-inhomogeneities, and conformation of the free-radical portion of the polymer chain. Most polymers intrinsically possess diamagnetic properties, so in order to study polymers with EPR, paramagnetic centers need to be incorporated into the polymer systems. Spin labeling and spin probing are main methods of covalently attaching paramagnetic centers to polymer chains or embedding them in polymer matrices through non-covalent interactions, respectively. Spin labeling and spin probing techniques for polymers and polymer systems (especially with nitroxide radicals) have also been studied, which have a profound impact on polymer science. This review focuses on the continuous wave EPR technique and introduces the recent advances in spin labeled polymers and spin probed polymer systems in EPR research.     

Recent developments in asymmetric catalysis using synthetic polymers with main chain chirality

Some recent developments in the use of main chain chiral polymer catalysts are summarized. These polymers are different from the traditional polymer catalysts that are prepared by anchoring monomeric chiral catalysts to an achiral polymer backbone. Three classes of synthetic main chain chiral polymers are discussed including: (1) helical polymers represented by polypeptides; (2) polymers with flexible chiral chains such as polyesters and polyamides; and (3) polymers of rigid and sterically regular chiral chains represented by chiral conjugated polybinaphthyls. Some of these polymer catalysts have shown high enantioselectivity in asymmetric organic transformations.     

Specificity of the application of disperse and fibrous fillers in heterophase polymer materials

The mechanism of the reinforcing effect of fillers in polymer composition is studied and the relation between the properties and structure of materials is established. It is shown that, upon the addition of even a small amount of filler, properties of polymers change markedly due to intermolecular interactions. Variations in the composition of filled polymers and conditions of their preparation make it possibly to regulate properties of polymers within noticeably wide ranges. Specific features of polymer compositions filled with polymer fibers, the effect of fiber length, and the degree of orientation on the strength of composition are considered. For crosslinked epoxy urethane polymers, the effect of glass and polycaproamide (capron) fibers on the mechanical properties of polymer clutches in glassy and rubbery states is studied. The possibility to realize the shape memory effect for shrinkable filled polymer clutches is demonstrated.     

填充聚合物的熔体流变学

颗粒填充聚合物（包括聚合物纳米复合材料）溶体通常表现出模量升高、频率依赖性的改变以及高含量填充体系的屈服行为等与单纯聚合物明显不同的流变行为,并且这些流变特性还会受到填料含量、形状尺寸以及颗粒-聚合物之间相互作用等诸多因素的影响。填充聚合物的宏观流变行为是与其微观结构的形成和演化以及高分子链在特定条件下的阻尼松弛过程密切联系在一起的。本文综述了颗粒填充聚合物（包括聚合物纳米复合材料）在力场作用下的流变性以及各种因素对其流变行为的影响,尤其是着重阐述了聚合物纳米复合材料的流变松弛机理和基于热力学理论建立起来的、描述填充体系熔体流变行为的Leonov模型。     

Synthetic Uniform Polymers and Their Use for Understanding Fundamental Problems in Polymer Chemistry

Summary: A uniform polymer is a polymer composed of molecules that are uniform with respect to molecular weight and constitution. Besides natural uniform polymers such as nucleic acids and polypeptide, synthetic uniform polymers have been obtained by a variety of approaches. In particular, a combination of living polymerization and supercritical fluid chromatography (SFC) separation is one of the promising ways for the preparation of uniform polymers. End‐functionalized uniform polymers enabled us to prepare uniform polymer architectures such as block, graft, comb, and star polymers. Their use for understanding the fundamental problems in polymer chemistry is discussed; topics include crystallization of polymers, chain conformation in solution, and association of stereoregular polymers in solution.

SFC traces of isotactic PMMA containing an authentic sample of the 45‐mer (a) and of the isolated uniform PMMA of 100‐mer (b).     

The Role of Hydrophobicity in the Antimicrobial and Hemolytic Activities of Polymethacrylate Derivatives

We synthesized cationic random amphiphilic copolymers by radical copolymerization of methacrylate monomers with cationic or hydrophobic groups and evaluated their antimicrobial and hemolytic activities. The nature of the hydrophobic groups, and polymer composition and length were systematically varied to investigate how structural parameters affect polymer activity. This allowed us to obtain the optimal composition of polymers suitable to act as non-toxic antimicrobials as well as non-selective polymeric biocides. The antimicrobial activity depends sigmoidally on the mole fraction of hydrophobic groups (f_HB). The hemolytic activity increases as f_HB increases and levels off at high values of f_HB, especially for the high-molecular-weight polymers. Plots of HC₅₀ values versus the number of hydrophobic side chains in a polymer chain for each polymer series showed a good correlation and linear relationship in the log–log plots. We also developed a theoretical model to analyze the hemolytic activity of polymers and demonstrated that the hemolytic activity can be described as a balance of membrane binding of polymers through partitioning of hydrophobic side chains into lipid layers and the hydrophobic collapsing of polymer chains. The study on the membrane binding of dye-labeled polymers to large, unilamellar vesicles showed that the hydrophobicity of polymers enhances their binding to lipid bilayers and induces collapse of the polymer chain in solution, reducing the apparent affinity of polymers for the membranes.     

Trends in Structural Polymer Science in Industry

Plastics production has grown rapidly in the past 30 years. The versatility of plastics which is not exceeded by any other class of materials, guarantees that polymers will continue to be very important in the future. However, at present a distinct change is taking place in polymer research and development. While in the pioneering days of plastics new polymer properties were determined by the choice of suitable monomers, today the commercialization of polymers from new monomers is restricted to a few specialities with a rather modest production volume. On the other hand, the number of new polymers derived from old monomers is increasing very rapidly. The development of highly selective catalysts and advances in reactor technology have provided the means for producing new tailor-made polymers. The same is true regarding new polymer blends and alloys based on old polymers: blending immiscible polymers yields materials with property profiles superior to the features of the individual components. Using selected examples, this paper will discuss trends, possibilities and challenges for structural polymer research in industry. © 1997 John Wiley & Sons, Ltd.     

Local Transient Jamming in Stress Relaxation of Bulk Amorphous Polymers

Bulk amorphous polymers become stretched and parallel-aligned under loading stress,and their intermolecular cooperation slows down the subsequent stress relaxation process.By means of dynamic Monte Carlo simulations,we employed the linear viscoelastic Maxwell model for stress relaxation of single polymers and investigated their intermolecular cooperation in the stress relaxation process of stretched and parallel-aligned bulk amorphous polymers.We carried out thermal fluctuation analysis on the reproduced Debye relaxation and Arrhenius fluid behaviors of bulk polymers.We found a transient state with stretch-coil coexistence among polymers in the stress relaxation process.Further structure analysis revealed a scenario of local jamming at the transient state,resulting in an entropy barrier for stretch-coil transition of partial polymers.The microscopic mechanism of intermolecular cooperation appears as unique to polymer stress relaxation,which interprets the hydrodynamic interactions as one of essential factors raising a high viscosity in bulk amorphous polymers.Our simulations set up a platform of molecular modeling in the study of polymer stress relaxation,which brought new insights into polymer dynamics and the related mechanical/rheological properties.