甲壳型液晶高分子研究进展与展望

简要介绍了甲壳型液晶高分子的模型理论, 概述了当前国内外对甲壳型液晶高分子设计、 液晶相态、 性质及基于甲壳型液晶高分子的嵌段共聚物体系的设计和自组装性质等研究进展, 展望了今后的研究方向.     

NONBRIDGED HALF-TITANOCENES CONTAINING ANIONIC ANCILLARY DONOR LIGANDS: PROMISING NEW CATALYSTS FOR PRECISE SYNTHESIS OF CYCLIC OLEFIN COPOLYMERS (COCs)

Precise,efficient copolymerizations of ethylene with cyclic olefins[norbornene(NBE),cyclopentene(CPE)]using nonbridged half-titanocenes of type,Cp'TiCl_2(L)(Cp'=cyclopentadienyl group,L=aryloxo,ketimide)-MAO catalyst systems have been summarized.CpTiCl_2(N=C'Bu_2)exhibited both remarkable catalytic activity and efficient NBE incorporation for ethylene/NBE copolymerization:the NBE incorporation by Cp'TiCl_2(X)(X=N=C'Bu_2,O-2,6-'Pr_2C_6H_3; Cp'=Cp,C_5Me_5,indenyl)was related to the calculated coordination ...     

三氮唑类席夫碱的合成及其荧光性能

近年来,Schiff碱因其结构的多样化以及具有光、电、磁等物理材料性能[1-3]的配位化学性能[4-5]等引起人们的关注,同时一些特殊结构的Schiff碱的合成和性质研究具有更为重要的理论意义和应用价值.     

Synthesis of phenothiazine‐based electroluminescent polymers with a stable emission property

Two phenothiazine‐based polymers were synthesized by the Heck reaction of 3,7‐divinyl‐N‐octyl‐phenothiazine with 3,7‐diiodo‐N‐octyl‐phenothiazine and 5,8‐dibromo‐2,3‐diethylquinoxaline. The polymers were characterized by the measurements of ¹H‐NMR, IR, TG, GPC, CV, UV–Vis, and FL. The results indicated that the introduction of quinoxaline group makes the absorption, PL, and EL emission maxima red‐shifted. The EL emission maximum and the CIE 1931 coordinate value are stabilized at a constant value with the increase in operating voltages. Therefore, the polymers have a stable electroluminescent emission property. Copyright © 2008 John Wiley & Sons, Ltd.     

Glass bead grafting with poly(carboxylic acid) polymers and maleic anhydride copolymers

Glass beads were etched with acids and bases to increase the surface porosity and the number of silanol groups that could be used for grafting materials to the surfaces. The pretreated glass beads were functionalized using 3‐aminopropyltriethoxysilane (APS) coupling agent and then further chemically modified by reacting the carboxyl groups of carboxylic acid polymers with the amino groups of the pregrafted APS. Several carboxylic acid polymers and poly(maleic anhydride) copolymers, such as poly(acrylic acid) (PAA), poly(methacrylic acid) (PMA), poly(styrene‐alt‐maleic anhydride) (PSMA), and poly(ethylene‐alt‐maleic anhydride) (PEMA) were grafted onto the bead surface. The chemical modifications were investigated and characterized by FT‐IR spectroscopy, particle size analysis, and tensiometry for contact angle and porosity changes. The amount of APS and the different polymer grafted on the surface was determined from thermal gravimetric analysis and elemental analysis data. Spectroscopic studies and elemental analysis data showed that carboxylic acid polymers and maleic anhydride copolymers were chemically attached to the glass bead surface. The improved surface properties of surface modified glass beads were determined by measuring water and hexane penetration rates and contact angle. Contact angles increased and porosity decreased as the molecular weights of the polymer increased. The contact angles increased with the hydrophobicity of the attached polymer. The surface morphology was examined by scanning electron microscopy (SEM) and showed an increase in roughness for etched glass beads. Copyright © 2007 John Wiley & Sons, Ltd.     

Evaluation of molecularly imprinted membranes based on different acrylic copolymers

Polyacrylonitrile and its copolymers with different functional monomers (itaconic acid, acrylic acid and acrylamide) were synthesized via water-phase precipitation polymerization in order to prepare molecularly imprinted polymer (MIP) membranes with recognition properties for the flavonoid naringin (NR). Membranes were prepared by phase inversion technique using dimethylformamide (DMF) as the solvent and adding naringin as template molecule to the casting solution. For comparison, membranes without template (blank) were prepared and tested. All MIP membranes showed high specific binding capacity; among them, the membrane prepared with the copolymer containing acrylamide as functional group, showed the highest binding capacity. Blank membranes only showed non-specific binding. The bound template was totally recovered and regenerated membranes maintained their initial binding capacity after reuse.     

The future of reversible addition fragmentation chain transfer polymerization

We examine the reversible addition fragmentation chain transfer (RAFT) process with regard to its potential and limits in future industrial applications (including those conducted on a larger scale) as well as materials science. The outlook for the RAFT process is bright: Its unrivaled inherent process simplicity coupled with a wide tolerance to monomer classes and functionalities makes it a prime candidate for the use in large reactors. At the same time, it allows for ready access to complex macromolecular architectures of variable shape and size. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5715–5723, 2008     

(20S)-20-羟基胆甾烷-3,16-二酮的合成

以妊娠双烯醇酮醋酸酯为起始原料, 经过7步反应以13.1%的总收率合成了一个具有抗4种肿瘤细胞(ED₅₀＝1 μg/mL)的海洋天然产物(20S)-20-羟基胆甾烷-3,16-二酮. 关键反应为底物控制的不对称杂原子共轭加成反应.     

Synthesis of well‐defined polymeric activated esters

Monomers bearing an activated ester group can be polymerized under various controlled polymerization techniques, such as ATRP, NMP, RAFT polymerization, or ROMP. Combining the functionalization of polymers via polymeric activated esters with these controlled polymerization techniques generate possibilities to realize highly functionalized polymer architectures. Within this highlight two different research areas of activated esters in polymer science will be discussed: (i) the preparation of defined reactive polymer architectures by controlled polymerization techniques and (ii) the preparation of defined reactive thin films. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6677–6687, 2008