[PDF] Polymer Information on STN文件格式: PDF/Adobe Acrobat. POLYLINK command. STNote 30: Enhanced Polymer Searching in REGISTRY at:. . or enter HELP POLYLINK at an arrow prompt. Polymer Class Terms ... - 类似网页 [PDF] Polymer Class Terms in the Registry File文件格式: PDF/Adobe AcrobatType of Polymer Retrieved. Amino Resin. AR. Condensation polymers of amines with aldehydes (mainly formaldehyde). IN Formaldehyde, polymer with 1 ... IN 2,6-Pyridinedicarboxylic acid, polymer with [1,1'-biphenyl]-3,3',4,4'-tetramine ... - 类似网页[ 站内的其它相关信息 ] ... - [ 翻译此页 BETA ]类似网页 Polymer Specific User Guides - Thomson Scientific - [ 翻译此页 BETA ]The System Description details the structure of the Polymer Indexing System including autoposting and linking. Examples of creating searches using linking are provided and there are worked examples for all hosts. Download a PDF copy ... ts/support/userguides/polymerguides - 27k - 网页快照 - 类似网页 [PDF] POLYMERS文件格式: PDF/Adobe Acrobat - HTML 版The first synthetic polymer, a phenol-formaldehyde polymer, was introduced under the name “Bakelite”, by Leo ... Bakelite, a phenol-formaldehyde polymer, was the first completely synthetic plastic, first made by Leo Baekeland in ... - 类似网页 [PDF] Hiromi Yamakawa Modern Theory of Polymer Solutions文件格式: PDF/Adobe Acrobat - HTML 版Modern Theory of Polymer Solutions. Copyright c 1971 by Hiromi Yamakawa. Printed in the United States of America. All rights reserved. No part of this book ... is represented by the lattice theory of polymer solutions, which was de- ... - 类似网页 中国科技在线---科技成果首页2745-2758 Sensing the glass transition in thin and ultrathin polymer films via fluorescence probes and labels Christopher J. Ellison, John M. Torkelson Abstract PDF Full Text (Size: 210K) HTML Full Text Published Online: 29 Oct 2002 ... - 28k - 网页快照 - 类似网页 中国科技在线---科技成果首页Abstract PDF Full Text (Size: 105K) HTML Full Text Published Online: 19 Nov 2002 DOI 671-675 Relationship between thickness of polymer films and their oxidation on copper substrate DG Lin, EV Vorobieva ... - 32k - 网页快照 - 类似网页 [PDF] Fiber and Polymer Science文件格式: PDF/Adobe Acrobat - HTML 版The fiber and polymer science major is concerned. with the physical, chemical, and structural properties. of fibers and polymers and how these ... and polymer performance and end-use. The Program. All students in this major take a com- ... - 类似网页 [PDF] PL2-1 Phys. Props of Polymers文件格式: PDF/Adobe Acrobat - HTML 版strips or beads. Plastic products contain additives, fillers, plasticizers. (agents making the polymer more flexible), stabilizers, and lubricants that. may alter the properties. Students should select the plastic that their ... - 类似网页 [PDF] Forces on a colloidal particle in a polymer solution: a study ...文件格式: PDF/Adobe Acrobat - HTML 版Physics Department and Polymer Interfaces Center, Lehigh University, Bethlehem, PA 18105,. USA. Received 15 July 1996. Abstract. ... where µ is the shear modulus and κ the bulk modulus of the polymer solution. The above ... - 类似网页 [PDF] Single-Polymer Dynamics in Steady Shear Flow文件格式: PDF/Adobe Acrobat - HTML 版tion of shear rate, ˙, for two different polymer relaxation times, . In contrast. to the behavior in pure elongational flow, ... flow, as viewed in the polymer’s center-of-mass frame. A velocity gradient perpendicular to the ... - 类似网页 [PDF] Elastic inertial instability in a polymer solution flow文件格式: PDF/Adobe Acrobat - HTML 版a polymer solution is studied experimentally. To achieve this goal, solution elasticity is varied. by three orders of magnitude and a diagram of ... Elastic phenomena in flows of polymer solutions have lately been attracting increasing ... - 类似网页 MIT OpenCourseWare | Materials Science and Engineering | ...MIT OpenCourseWare » Materials Science and Engineering » Polymer Engineering, Fall 2003 ... Problem (PDF) Problem (PDF) Problem (PDF) Problem (PDF) Problem (PDF) Problem (PDF) Problem (PDF) ... 3-064Polymer-EngineeringFall2003/Assignments/ - 26k - 网页快照 - 类似网页 MIT OpenCourseWare | Materials Science and Engineering | ...MIT OpenCourseWare » Materials Science and Engineering » Polymer Engineering, Fall 2003 ... 34, Elements of Design (PDF). 35, Materials Selection (PDF). 36, Design for Manufacturing, Stiffness, and Strength ... 3-064Polymer-EngineeringFall2003/LectureNotes/ - 29k - 网页快照 - 类似网页[ 站内的其它相关信息 ] [PDF] Polymer Processors文件格式: PDF/Adobe Acrobat - HTML 版The architecture of polymer processors is based. on a recent theoretical model of analog. computation called the extended analog ... The polymer field-effect transistor was. developed by Garnier. Polymer processors use ... - 类似网页 [PDF] Microsoft PowerPoint - 文件格式: PDF/Adobe Acrobat - HTML 版Polymer Processing III. Thermoforming. S. Kim. 2. Design for Manufacturing ... the polymer flow, called die swell. Die Swell. S. Kim. 12. Viscousity. Shear thinning: paints. Shear Rate ... 21AB74F9-D450-4189-B3B2-C3EB1F674D2C/0/ - 类似网页 [PDF] MATLAB Files for 1D polymer flow problem File: 文件格式: PDF/Adobe Acrobat - HTML 版This program calculates the velocity profile of a shear-thinning polymer fluid in pressure-driven ... polymer fluid in pressure-driven laminar flow between two. % infinite, parallel plates separated by a distance B, the top ... A0255E6A-3E72-436E-A238-5A8DE405BF3E/0/ - 类似网页[ 站内的其它相关信息 ] [PDF] Scalable Synthesis of a New Class of Polymer Microrods by a Liquid ...文件格式: PDF/Adobe Acrobatable process for the formation of a new class of polymer mi-. crorods with large aspect ratio that can be as ... The polymer microrod synthesis is based on a new liquid±. liquid dispersion technique, presented schematically in Fig- ... - 类似网页 [PDF] Effects of polymer polydispersity on the phase behaviour of ...文件格式: PDF/Adobe Acrobatto be such that phase diagrams become nearly independent of polymer polydispersity and can. therefore be inferred from the corresponding ... behaviour in a manner that depends only weakly on the polymer polydispersity. In assessing ... - 类似网页[ 站内的其它相关信息 ] [PDF] Classes of small-world networks文件格式: PDF/Adobe Acrobat - HTML 版Center for Polymer Studies and Department of Physics, Boston University, Boston, MA 02215. Communicated by Herman Z. Cummins, City College of ... polymer chain seems to be well described (29) by the small-world. networks of ref. 2. Fig. ... Papers/ - 类似网页 [PDF] Collapse of a semiflexible polymer in poor solvent文件格式: PDF/Adobe Acrobat - HTML 版We investigate the dynamics and pathways of the collapse of a single, semiflexible polymer in a poor solvent. via three-dimensional Brownian Dynamics simulations. An example of this phenomenon is DNA condensation ... - 类似网页 [PDF] Control of Energy Transfer in Oriented Conjugated Polymer ...文件格式: PDF/Adobe Acrobat - HTML 版pores to isolated, aligned polymer chains within the pores. Energy migration. along the conjugated polymer backbone occurred more slowly than Förster. energy transfer between polymer chains. The different intrachain and interchain ... schwartz/schwartz_pubs/ - 类似网页 [PDF] Floating Liquid Phase in Sedimenting Colloid-Polymer Mixtures文件格式: PDF/Adobe Acrobat - HTML 版colloid-polymer mixtures within the Asakura-Oosawa-Vrij model of hard sphere colloids and ideal. the ratio of buoyant masses of the two species is comparable to the ratio of differences. in density of the coexisting bulk ... 2004/ - 类似网页 [PDF] 8: A Classification of Linear Single-Strand Polymers (1988)文件格式: PDF/Adobe Acrobat - HTML 版The polymer literature lacks, at present, a widely applicable, internally consistent, and easily. recognizable system for classifying ... Thus I is a. homochain polymer, whereas II is a heterochain Dolymer. - 18 May 2001 ... books/pbook/ - 类似网页 [PDF] PEEK Polymer (Polyetheretherketone)文件格式: PDF/Adobe Acrobatpolymer for your application, Entegris’. material experts and engineers are available to. help you match the best material to your ... Polymer. Resin research and testing are conducted in. Entegris’ Materials Test Laboratory. Resins are ... - 类似网页 [PDF] POLYMER THIN FILMS UNDER SUPERCRITICAL CO文件格式: PDF/Adobe Acrobat - HTML 版coefficient and the glass transition in thin polymer films. The performance of the many applications of thin films ... polymer thin films on a nanometer scale. To achieve this under. in situ conditions, we have developed a temperature ... - 类似网页 [PDF] Bulk and surface characterization of a dewetting thin film polymer ...文件格式: PDF/Adobe Acrobat - HTML 版thickness of each constituent polymer species and the total thickness of the film with STXM, while ... vature of the polymer/polymer interface. We present here the. combination of near-edge x-ray absorption fine structure ... - 类似网页 [PDF] Phase segregation in polymer thin films: Elucidations by -ray and ...文件格式: PDF/Adobe Acrobat - HTML 版binary polymer blends the spinodal decomposition and coarsening process can be more complex. in thin films where various boundary conditions are ... mass thickness maps of each constituent polymer, and compared the summed maps (total ... - 类似网页 [PDF] Model colloid–polymer mixtures in porous matrices: density ...文件格式: PDF/Adobe Acrobat - HTML 版is a model colloid–polymer mixture in contact with a porous matrix. As in the AO model. the colloid particles are described by HS and globular non-adsorbing polymer coils as ideal. effective spheres with a hard core cross interaction of ... - 类似网页 无主题 - [ 翻译此页 BETA ]Because there exists an enormous difference between these two structural components, polymer PDF profiles manifest a ... Existing polymer PDF studies have, on the whole, only touched upon a few of the possible host systems which could ... - 45k - 网页快照 - 类似网页 [PDF] Polymer Vesicles文件格式: PDF/Adobe Acrobat - HTML 版with RJ Farris at the University of Massachusetts,. who knows an awfullot about rubber. REVIEW. Polymer Vesicles ... tions of polymer vesicles will rely on exploiting unique property-perfor-. mance relations, but results to date already ... - 类似网页 [PDF] Constitutive modeling of nanotube–reinforced polymer composites文件格式: PDF/Adobe Acrobat - HTML 版polymer/nanotube interface is highly dependent on the local molecular structure and bonding. ... lattice structures of the nanotube and polymer chains cannot be considered continuous, and the bulk mechanical properties can no ... - 类似网页 [PDF] Switchable Fresnel lens using polymer-stabilized liquid crystals文件格式: PDF/Adobe AcrobatThe prepared polymer-stabilized LC sample is highly transparent in the voltage-off state. Figure 1 shows the schematic diagram illustrating ... polymer-stabilized LC Fresnel zone plate. In the low voltage regime, the LC molecules in the ... 2003/ - 类似网页 [PDF] Micromechanical Modeling of Piezoelectric Polymer Composites文件格式: PDF/Adobe Acrobat - HTML 版PVDF is a orthotropic, semi-crystalline polymer which exhibits a piezoelectric effect ... In this study, the PVDF polymer was reinforced with infinitely-long graphite fibers and. spherical SiC particles. The fibers were unidirectionally ... - 类似网页 [PDF] KATECH (Lithium Polymer) 4-Passenger NEV Range and Battery Testing ...文件格式: PDF/Adobe Acrobat - HTML 版The Invita (Figure 1) was equipped with a Kokam Engineering lithium polymer battery, which was. to be characterized as part of the baseline ... for the constant speed range test procedure). ... - 类似网页 [PDF] Numerical study of polymer tumbling in linear shear flows文件格式: PDF/Adobe Acrobat - HTML 版In principle, if the polymer tumbles in the shear plane, we should consider a time-dependent PDF of φ on a ... of the tumbling time PDF changes with increasing Wi number, we can rescale the time and the polymer size in the ... - 类似网页 [PDF] POLYMER STATISTICAL MECHANICS文件格式: PDF/Adobe Acrobatpolymer physical chemists and physicists. The reason is that it is concerned with. the many-body problem which cannot be solved exactly. ... ation) equations for the averages of normal coordinates for a ring polymer. If the ... doi/pdf/ - 类似网页 『An Introduction to Polymer Physics』by David I. Bower,pdf ...书名】An Introduction to Polymer Physics 【作者】David I. Bower 【出版】Cambridge University Press 【格式】PDF格式,465pages 【语言】English 【简介】全面阐述高分子 物理的研究方法、过程。重点描述聚合物结构、特征的研究方法。 附件1: CUP,. ... - 6k - 网页快照 - 类似网页 [PDF] Understanding morphology evolution and roughening in phase ...文件格式: PDF/Adobe Acrobatmer blending has been of long-standing interest to the polymer industry. Underlying the. commercialization of polymer blends has been several ... polymer blends undergoing simultaneous phase separation and wetting can be described. Ini- ... - 类似网页 [PDF] Activity: Polymer Clay Millefiori Cane Beads Objectives: Students ...文件格式: PDF/Adobe Acrobat - HTML 版two or more packages (and colors) of Sculpey III® polymer clay (softer to work with than. Fimo® and some other brands. ... with a safer material, polymer clay. Use materials to create a functional and decorative object. ... anthro/beads/pdfs/ - 类似网页 [PDF] Large magnetoresistance at room temperature in semiconducting ...文件格式: PDF/Adobe Acrobat - HTML 版particular, polyfluorene has emerged as a high brightness, high-efficiency π-conjugated polymer. for use in OLEDs [4]. ... A thin film with thickness larger than the polymer’s conjugation-length may therefore be considered as bulk. ... - 类似网页 [PDF] Meso- and Nano-scaled Polymer Fibers and Tubes文件格式: PDF/Adobe Acrobat - HTML 版Dissertation about the development, production, characteristics and industrial applications of nanofibers and structures. Author: Jun - 类似网页 [PDF] ELASTIC PRINCIPAL MANIFOLDS AND THEIR PRACTICAL APPLICATIONS ...文件格式: PDF/Adobe Acrobat - HTML 版Institute of Polymer Physics, ETH, Switzerland. . Andrey Zinovyev. 1. Institut des Hautes Études Scientifiques (IHES), Bures-sur-Yvette, France. zinovyev@. Abstract. Principal manifolds defined as ... - 类似网页 [PDF] Scaling and universality in economics: empirical results and ...文件格式: PDF/Adobe Acrobat - HTML 版and Stanley HE 2001 Quantifying stock. price response to demand fluctuations. Preprint cond-mat 0106657. H Eugene Stanley and Vasiliki Plerou are. at the Center for Polymer Studies and. Department of Physics, Boston University, ... - 类似网页 [PDF] Ionic polymer–metal composites: II. Manufacturing techniques文件格式: PDF/Adobe Acrobat - HTML 版experimental procedures in manufacturing ionic polymer–metal composites. (IPMCs) that, if fully developed, can be used as ... of hydrophobic polymer is mixed into a paste with the. liquid phase monomers. The initiator and a plasticizer ... - 类似网页 [PDF] Compact low loss single air interface bends in polymer waveguides文件格式: PDF/Adobe AcrobatPhotonic integrated circuits; () Polymer waveguides-fibers; () Thin films;. () Deposition and fabrication ... transferred to the polymer sidewall. We are currently working on reducing this roughness. (C) 2004 OSA ... 2004_OpEx_SAIBs%20in%20PFCB% - 类似网页 [PDF] Role Of Polymer Loops In DNA Replication文件格式: PDF/Adobe Acrobat - HTML 版S. Jun and J. Bechhoefer, “Role of Polymer Loops in DNA Replication,” Physics in Canada, 59 (2), pp. 85-92 (2003). ... static and dynamic properties of polymer loops. For example, long polymers must search ... - 类似网页 [PDF] THERMOTROPIC LIQUID CRYSTALLINE POLYMER FIBERS 1. Introduction ...文件格式: PDF/Adobe Acrobat - HTML 版Extensive technical paper describing a model for a process which realistically couples the hydrodynamics, the LCP dynamics and the temperature field, along with the free surface and boundary conditions of the manufacturing process of ... forest/papers/ - 类似网页 Postscript files of alpha version of forthcoming fourth edition of ... - [ 翻译此页 BETA ]Path Integrals. in Quantum Mechanics, Statistics, Polymer Physics, and Financial Markets. Read Content and Author Blurbs · Fetch PDF files of the forthcoming fourth edition by clicking on this line. Contains Preface (Chap. ...
材料大全A到Z (金属、陶瓷、高分子、复合材料) (免费) 资源简介 材料模拟计算算法库MAP 资源简介 : Composites/Plastics 资源简介 Kirk-Othmer Encyclopedia of Chemical Technology Online(Kirk-Othmer化工技术百科全书) (部分免费) 资源简介 Materials Research to Meet 21st Century Defense Needs (材料与国防) 资源简介 PoLyInfo (高分子材料设计所需的各种数据) (免费) 资源简介 Super-tough carbon-nanotube fibres (碳纳米管纤维) ... 资源简介 美国加州理工学院:Robert H. Grubbs教授的研究小组 资源简介 涂料和油漆工业排名榜(主要为北美地区、前50位) ... 资源简介 英国的材料化学研究世界领先(2002-11-22) 资源简介 Bell Labs (贝尔实验室, 纳米技术/分子自组装/导电高分子) 资源简介 CAMPUS (塑料产品数据库, 免费) 资源简介 工程塑料国家重点实验室, 中国科学院化学研究所 资源简介 2004年国际纳米复合材料会议 (2004-09-01)
《高分子材料科学与工程》征稿简则本刊主要报道与高分子材料科学与工程领域有关的高分子化学、高分子物理及物化、反应工程、结构与性能、成型加工理论与技术、材料应用与新技术开发、研究方法及测试技术等方面的研究成果。栏目包括:专论与综述;合成实验与工艺;结构与性能;分析测试、加工与应用;新技术与产品开发;教学讨论与快讯。一、投稿要求:1.来稿文摘自负。稿件内容符合本刊报道宗旨,论点鲜明,数据可靠,文字简练。2.来稿参照本刊格式撰写。审稿期限3个月。超过3个月未接到录用通知,作者可自行处理。请作者保证所投稿件为原创作品,凡已录用的稿件请按录用函中的修改建议进行修改。修改稿用E-mail返回我刊。修改稿50日不返回者,按自然退稿处理。无一稿两投,并且不涉及保密及其他与著作权有关的侵权问题。二、稿件撰写要求:1.【论文题名】论文题名要求准确、简明地表达文章的主题内容,应具有文献检索价值,字数不超过20字,不应有非规范的缩略词、符号、代号。资助课题须在首页下注中注明资助来源、基金项目号、联系人及其研究方向和E-mail地址。2.【摘要】摘要应是一篇独立、完整的短文,着重反映其研究目的、方法和结果,不加任何注释和评论。采用第三人称,一般不超过200字。3.【关键词】关键词应选取便于检索并反映文章主要内容词组。关键词不超过8个。中英关键词须一一对应。4.【图、表】图表位于相应的正文段落之后。图的线条要清晰、数据要清楚。表格应采用三线表。图、表中的“量与单位”之间用“/”表示。图的尺寸(以打印出来的为准)如下:a.. 光谱图、核磁共振谱图,不画纵坐标,纵向约38mm,横坐标约57mm;b. 左右均有纵坐标的,纵坐标约38mm,横坐标约42mm;c. 只有左边纵坐标的,纵坐标约38mm,横坐标约48mm;d. 照片的纵坐标约35mm,横坐标约40mm,一般3~5张。5.【参考文献】必须是在论文中直接引用的已发表在正式出版物上的文献。各篇文献应按照正文引用的顺序编号。参考文献的作者需列前3人,后加“等”或“et al”。英文参考文献的作者姓名一律采用姓在前、名(首字母缩写)在后的形式。中文参考文献的作者姓名和出版物需中英文对应。
兄弟这是我的给你用下吧。反正也毕业了,给分啊附件1:外文资料翻译译文含有非共面的2,2'-二甲基-4,4'-二苯基单元和纽结性的二苯甲撑键的高度有机可溶解的聚醚酰亚胺的合成和特征两种新的双醚酐2,2'-二甲基-4,4'-双[4-(3,4-二羧基苯氧基)]二苯基二酐(4A)和双[4-(3,4-二羧基苯氧基)苯基]二苯甲烷二酐(4B)可以由三步反应制得。首先,由4-硝基邻苯二甲腈分别与2,2'-二甲基二苯基-4,4'-二醇和双(4-羧基苯基)二苯甲烷发生硝基取代,然后双醚四腈在碱性条件下水解和随后的双醚四酸脱水。一系列的新的高度有机可溶解的聚醚酰亚胺采用常规的两步合成法由双醚二酐和各样的二胺制得。制得的聚醚酰亚胺固有粘度在-范围内。GPC测量显示这些聚合物的数均分子量和重均分子量分别高达45000和82000所有的聚合物表现出典型的无定型衍射图样。几乎所有的聚醚酰亚胺都表现出优良的溶解性以及容易在不同的溶剂中,例如N-甲基-2-吡咯烷酮,N,N-二甲基乙酰胺(DMAC),N,N-二甲基甲酰胺,吡啶,环己酮,四氢呋喃和氯仿。这些聚合物的玻璃化转变温度在224-256℃范围内。热重分析表明这些聚合物都是稳定的,在氮气下10%重量损失点在489℃以上。等温重量分析结果说明这些聚合物在350℃的静态空气中等温老化的重量损失都在-%。具有韧性和柔性的聚合物膜可以通过其DMAC溶液浇注制得。这些膜的抗张强度具有84-116MPa,抗张模量具有-。引言芳香族聚酰亚胺由于其突出的热稳定性,因具有低介电常数而有优良的电绝缘性,对常用基材具有好的黏附性,以及卓越的化学稳定性,及其在半导体和电子封装工业领域被广泛的应用。但是由于最初的聚酰亚胺是不溶不熔的,它们在许多领域的应用受到限制。因此,目前已经进行了大量的研究来寻找新的方法来绕过这些局限性.改变聚酰亚胺回避化学结构的通用方法是引入柔性基团和/或庞大的单元到聚合物主链中。聚醚酰亚胺作为芳香族的亲核取代反应产物得到迅速发展,又成为与市场需要接轨的高性能的而且能够用注射挤出工艺制造的聚合物。GeneralElectric Co.开发并商业化的Ultem 1000就是一个重要的例子,它表现出比较好的热稳定性和良好的力学性能另外还有良好的可塑性。目前的研究主要集中在一系列新的有好的溶解性的聚醚酰亚胺的合成和特性化,主要基于包含异面的2,2'-二甲基-4,4'-二苯撑单元的4A和包含二苯甲撑纽结环的双[4-(3,4-二羧基苯氧基)苯基]二苯甲烷二酐的4B。在对位键合的聚合物链中结合2,2'-二取代的二苯撑降低了聚合物分子链间的相互影响。通过2,2'-二取代将苯环加在异面构象中,减弱了分子链间的分子间力,结晶倾向明显降低,溶解性显著提高。另外获得有机可溶性的聚酰亚胺的另一个有效途径是结合取代的甲撑键,例如异丙叉[(CH3)2C=]、六氟异丙叉和二苯甲撑单元,它们提供主链上的刚性苯环间的纽结,来提高聚合物的溶解性。聚合物主链中的纽结单元的出现降低了分子链的刚性,以至提高了聚合物的溶解性。试验发现有二苯甲撑单元的聚合物比含有异丙叉和六氟异丙叉单元的聚合物有更好的热稳定性。因此,结合异面的2,2'-二甲基-4,4'-二苯撑和纽结单元的二苯甲撑可以制成具有良好热稳定性的可溶性聚醚酰亚胺。不同的结构单元对聚合物性能的影响如溶解性、热稳定性和力学性能,这里也将讨论。实验步骤材料:原料二元醇,2,2'-二甲基-4,4'-二羟基-二苯(1A)和双(4-羟基苯基)二苯甲烷(1B)分别由2,2'-二甲基-4,4'-二氨基二苯和4,4'-二氯二苯甲烷制得。DMF,DMAC和吡啶在使用前减压蒸馏纯化,醋酐用真空蒸馏纯化。单体合成:见图12,2'-二甲基-4,4'-双[4-(3,4-二腈基苯氧基)]二苯(2A)。在100mL圆底烧瓶中加入()的2,2'-二甲基-4,4'-二羟基-二苯(1A)和(70mmol)的4—硝基邻苯二腈溶解在80ml的纯DMF中。加入无水碳酸钾(),浊液在室温下搅拌两天。然后将反应的混合物加入到500ml的水中沉析,得到浅黄固体产物,用水和甲醇重复冲洗,过滤和干燥。粗产品在乙腈中重结晶得到黄色晶体双(醚二腈)(2A),产率83%,熔点227-228℃。双[4-(3,4-二腈基苯氧基)苯基]二苯(2B)。合成2B的步骤和合成2A的步骤相似,用双(4-羟基苯基)二苯甲烷替换二元醇做反应物。同样在乙腈中重结晶两次得到棕色晶体双(醚二腈)(2B),产率86%,熔点219-220℃。2,2'-二甲基-4,4'-双[4-(3,4-二羧基苯氧基)]二苯(3A)。在100ml的圆底烧瓶中将()的双(醚四腈)(2A)加入到含有()gKOH的40ml水/40ml乙醇溶液。固体双醚四腈在一个小时内溶解。回流持续两天直到不再放出氨气。在过滤和减压下除去剩下的乙醇后,用200ml水稀释然后用分析纯盐酸酸化。过滤双(醚四酸)沉淀用蒸馏水洗涤直到滤液澄清。产率在92%。反应物因为热环化脱水而产生的吸收峰在165℃附近(用DSC)。双[4-(3,4-二羧基苯氧基)苯基]二苯(3B)。3B的合成步骤类似3A,只是用2B替换双(醚四腈)做反应物。产物收率为91%,熔点138-170℃。2,2'-二甲基-4,4'-双[4-(3,4-二羧基苯氧基)]二苯酐(4A)。在100ml的原地烧瓶中,将双(醚四酸)(3A)溶解于35ml冰醋酸和25ml醋酐的溶液中,回流24小时。然后,过滤混合物放置结晶一天。过滤出沉淀物再在醋酐中重结晶。过滤得到棕色晶体,用纯甲苯洗涤并在100℃下真空中烘干24h得到双(醚二酐)(4A)。产率81%,熔点217-218℃。双[4-(3,4-二羧基苯氧基)苯基]二苯酐(4B)。4B的合成步骤类似4A,只是用3B替换双(醚四酸)做反应物。获得产率84%,熔点262℃。聚合步骤:见图二。在搅拌下缓慢地将双醚二酐(4A)(,)加入到3,3',5,5'-四甲基-2,2'-双[4-(4氨基苯氧基)苯基]丙烷(5b)()的DMAC溶液中。混合物在室温下于氩气环境下反应2h形成聚醚酰亚胺酸预聚体(A-6b)。化学亚胺化可通过将3mlDMAC、1ml酸酐和吡啶加入到上述A-6b溶液中,在室温下搅拌1h升温至100℃反应3h。接着将均匀的溶液加入到甲醇中过滤,将沉析出的黄色固体用甲醇和热水洗涤,然后在100℃下干燥24h,得到聚醚酰亚胺A-7b。在浓度为温度为30℃的条件下,聚合物在DMAC中的固有粘度是。所有其他聚醚酰亚胺用采用相似步骤来制备。表征熔点用BUCHI装置的毛细管测量(型号 BUCHI 535)。红外光谱在4000-400cm‐1范围用JASCO IR-700光谱仪测量。13C和1H的核磁共振光谱由在的炭和的质子通过JEOLEX-400获得。所有的聚醚酰亚胺的固有粘度通过Ubbelohocle粘度计测得。用Perkin-Elmer2400装置作元素分析。用(GPC)凝胶渗透色谱的方法确定质均和数均分子量。四个300*水柱(105、104、103、50埃系列)由THF(四氢呋喃)冲洗液用来作GPC(凝胶渗透色谱)分析。用UV探测器(Gillon型号116)在254nm处监测,用聚苯乙烯做标样。在室温下,与胶片样品上用Ni过滤地Cu,Ka射线的X射线(30KV,20mA)衍射仪测得广角X射线衍射图样。热解重量通过流动速率为(100cm3·min‐1)的以20℃·min‐1的加热速率加热的空气或氮气的热解重量分析仪(TGA 250)来获得。差示量热分析通过Dupont的差示量热分析仪来实现,该差示量热分析仪的加热速率是20℃·min‐1。玻璃化转变温度就是它的屈服点。抗张性能通过一个载荷为10Kg的定向拉伸机测得的应力-应变曲线决定。通过ULVAC等温重量分析仪(型号7000)来获得等温重量分析。这项研究用厚度3cm的试样在应变速率为2cm·min‐1的条件下进行,在室温下用5个胶片样品(4mm宽,5cm长,厚)来测量。结果和讨论单体合成如图1所示,二醚酐由三步合成方法制得,以二元醇(1A和1B)与4-硝基邻苯二腈在室温下碳酸钾的存在下于无水的DMF中的亲核硝基取代开始。硝基取代反应最好在低温下进行,不要在高温(高于100℃)下进行。因为在高温下得到的产品(2A和2B)往往是黑色的。获得的双(醚二腈)2A和2B各自在碱性溶液中水解得到双(醚二酸)3A和3B。2A的水解反应需要进行两天。然而,2B因为其溶解性小于2A,所以2B的水解反应还要用更长的时间等到完全水解,完全水解的溶液变得澄清。在用盐酸酸化以前必需除去残留的乙醇,如果在水溶液中有未除尽的乙醇存在,往往使反应物在酸化的时候发粘,然后双(醚二酸)环化脱水得到双醚酐4A和4B。这些合成化合物的结构可以用元素分析、IR和NMR的方法的得到确认。例如,二醚酐的红外光谱显示出环酐的特征吸收峰在1837和1767cm-1,分别归属于酐基团中的C=O地对称和部对称的伸缩振动。NMR谱数据列在实验部分。NMR光谱提供了清晰的证据,在此制备的双(醚二酐)单体与预期结构是相互关联的。聚醚酰亚胺的制备聚醚酰亚胺是用常规的两步法合成的,如流程2所示。包括开环加成聚合行成聚醚酰胺酸和随后的化学环化脱水。一般聚醚酰亚胺酸的热环化脱水反应也可在减压高温(大约300℃)下进行。然而如此热环化脱水得到的产物比化学环化脱水产物的溶解性差。因为我们研究的目的就是制得有机可溶性的PEI,在此采用了化学环化脱水。聚醚酰胺酸的预聚物是通过聚醚二酐(4A合4B)缓慢地加入到二胺溶液中反应制得。然后将脱水剂如醋酐和吡啶的混合物加到获得的粘性聚醚酰胺酸溶液中得到各种PEI。这些PEI固有粘度在-(表1)。除了聚合物A-7c,这些PEI地数均分子量(——Mn)和重均分子量(——Mw)分别在32000和52000g/mol以上。以聚苯乙烯为标样采用GPC法测量,所有的聚合物膜都可以由其DMAC溶液浇注制得。所有的聚合物膜都是坚韧的、透明的、柔软的。这些膜都经受了拉力试验。聚合物表征聚合物的结晶性用广角X-射线衍射图谱检测。所有的聚合物都在2θ=8°和40°之间表现完全非晶样式,说明聚合物是非晶的,这个发现是合理的。因为异面结构2,2'-二取代苯撑单元的存在和二苯甲撑中的苯结构减弱了分子链间的分子间力,引起了结晶度的减少。一般,聚合物主链中二苯撑单元的存在导致刚性棒聚合物有高结晶性和低溶解性。尽管如此,在4,4´-二苯撑单元上结合2,2´-二甲基取代基,可以有效地降低聚合物的堆砌效应。值得注意的是聚合物链中含有对称的取代基往往带来好的堆砌。在甲撑结构中的二苯基取代,也可以看成是聚合物主链上的对称取代。尽管如此,二苯甲撑键往往以扭结构型存在,因此聚合物分子链的刚性降低了。因而结晶性也因为聚合物含有纽结链降低了。这些PEI在一些有机溶剂中的%(w/v)的溶解度也概括到了表2中。几乎所有的PEI都溶解在这些测试的溶剂中,包括N-甲基-2-吡咯烷酮、DMAC、吡啶、环己酮、四氢呋喃、甚至氯仿在室温下溶解。这些PEI有好的溶解性可以归结为柔软的醚键,异面的二苯撑和纽结键的存在。正是这些结构降低了分子间的作用力和刚性。这些PEI溶解性的对比暗示着含有二苯甲撑的PEI比含有2,2'-二甲基-4,4'-二苯撑单元的PEI有稍好的溶解性。这就说明了扭结单元对于增加聚合物的溶解性比异面的2,2'-二甲基-4,4'-二苯撑单元更有效。这些PEI地热稳定性也在表3中列出。用DSC法测得这些PEI的玻璃化转变温度(Tg's),其值在224-256℃范围内。DSC检测中没有发现熔融吸收峰,这也证明了PEI是非晶的。显而易见含有2,2'-二甲基-4,4'-二苯撑的单元比含有纽结键的聚合物显示出更高的Tg值。这是因为有二苯撑单元的聚合物比有纽结键的表现出更高的刚性。热重分析(TG)揭示了这些PEI有优良的热稳定性。它们在450℃以上仍然保持稳定。在氮气气氛下,这些聚合物有10%重量损失的温度(Td10)可以达到489-535℃。研究发现有二苯撑单元的2,2'-二甲基-4,4'-二苯撑的聚合物比那些有二苯甲撑键的单元有更高的Td10。通过对用二胺(A-C)制得的聚合物A-7a-A-7c的比较,可以发现有2,2'-二甲基-4,4'-二苯撑单元的聚合物(A-7c)比含有不对称的特丁基取代基团的聚合物(A-7a)表现出更高的Td10,含有四甲基取代的聚合物(A-7b)在这些聚合物中(A-7a-A-7c)表现出最低的Td10。和我们以前的研究中的相似发现差不多,异面结构比特丁基取代基和四甲基取代基团赋予聚合物更好的热稳定性。另外有2,2'-二甲基-4,4'-二苯撑单元的聚合物(B-7c)比含有不对称的特丁基取代基团的聚合物(B-7a)表现出更高的Td10,含有四甲基取代基的聚合物(B-7b)在这些聚合物中(B-7a-B-7c)表现出最低的Td10。在我们以前的研究中就发现异面结构2,2'-二甲基-4,4'-二苯撑在聚合物的主链上可以提高聚合物的溶解性。因为它降低了分子间作用力和刚性,就像以前的相似结论一样,在2,2'-二甲基-4,4'-二苯撑单元上结合上甲基取代基在有效范围内牺牲了聚合物少量的热稳定性但却提高了加工性。根据以前的研究结果,在苯撑单元上有四甲基取代的聚合物比没有的,不仅有效地提高了聚合物的溶解性还提高了聚合物的热氧稳定性。这些聚合物的IGA测试结果说明了异面二苯撑结构的聚合物比哪些有二苯甲撑纽结结构的聚合物有更高的热稳定性。IGA的结果说明了这些PEI有好的热氧稳定性,一般地,IGA结果与TGA数据相仿。特别地在静止的空气中350℃下进行20h的恒温老化,聚合物重量损失在-%(表3),通过重量损失值的对比发现,有2,2'-二甲基-4,4'-二苯撑单元的聚酰亚胺要比含有二苯甲撑单元的有稍高的热稳定性。2,2'-二甲基-4,4'-二苯撑的聚合物有较少的重量损失,包括PEI在空气中主链中的甲基结构被氧化生成(C=O)结构导致增重。通过热稳定性的对比,所有的这些聚酰亚胺都比我们以前报告过的聚酰亚胺热稳定性好。这些聚酰亚胺可以被称为新的高性能工程塑料。这两系列在DMAC溶液中用溶液浇注的方法得到的PEI膜的机械性能概括在表4中。这些坚韧有弹性的膜抗张强度在84-116MPa,断裂伸长率在6-12%,初始模量为-。这些膜有强而韧的物理性能,可以总结出含有2,2'-二甲基-4,4'-二苯撑单元的聚合物膜比有纽结的二苯甲撑键的强度大,这是非常合理的。在PEI中有4,4'-二苯撑单元表现出棒状结构以致聚合物链比纽结键有更高的刚性。通过对这些聚合物的机械性能的对比,聚酰亚胺A-7b-A-7c也比商业化的聚酰亚胺Ultem 1000(105MPa)有更高的抗张强度。所有这些聚酰亚胺的机械性能也必我们以前的报告中提到的要高。结论含有异面2,2'-二甲基-4,4'-二苯撑单元和含有扭结性的二苯甲撑键的两种新的双醚二酐用三步方法成功制得。一系列有适当的分子量的PEI用这些双醚二酐单体和不同的二胺制得。这些PEI可以很容易在多种有机溶剂中溶解,包括常用的有机溶剂如环己酮和氯仿。另一方面这些PEI有好的热稳定性和机械性能。因此这些新的可溶性的PEI可以被认为是新的高性能的工程塑料。这里提供的结果也说明了含有2,2'-二甲基-4,4'-二苯撑单元的聚合物比那些有扭结性二苯甲撑键的聚合物表现出更高的热稳定性和机械性能。然而,后者比前者有更好的溶解性。
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