叶立德活性聚合制备基于聚亚甲基的大分子单体

利用叶立德活性聚合方法制备了两种基于聚亚甲基的大分子单体. 其中一种是以叶立德活性聚合制备的主链链端含有羟基的聚亚甲基(PM-OH)为原料, 通过链端羟基的基团转换, 得到链端含有甲基丙烯酸酯基的大分子单体. 另一种则是以硼烷-四氢呋喃(BH₃-THF)和二乙烯基苯反应得到的三烷基硼中间体为催化剂和引发剂, 然后进行叶立德活性聚合, 再经过二水合氧化三甲胺(TAO)的氧化, 最终得到基于聚亚甲基的一端含有羟基另一端含有苯乙烯基的大分子单体. 通过高温核磁氢谱、傅立叶红外光谱和高温凝胶色谱法表征了这两种大分子单体的链结构和分子量及其分布.     

链转移剂单体存在下苯乙烯乳液聚合反应研究

以α-甲基丙烯酸-3-巯基己酯(MHM)为链转移剂单体,过硫酸钾(KPS)为引发剂,十二烷基苯磺酸钠(LAS)为乳化剂,通过乳液聚合合成支化聚苯乙烯(BPSt).采用1H-NMR和三检测体积排除色谱(TD-SEC)对聚合反应过程和合成的聚合物进行了表征分析.结果表明,在合适的乳化剂用量、引发剂用量和聚合反应温度等条件下,反应初期生成的初级链可以完全转化成支化聚合物,在高单体转化率下不发生交联得到较窄分子量分布的高分子量支化聚苯乙烯(Mn,SEC1.4×105,Mw,MALLS2.0×106,PDI4.5),而且所得聚合物表现出很高的支化程度(g'=0.5~0.6).     

乙烯基单体与含氮氧稳定自由基单体的原子转移自由基共聚合研究

通过苯乙烯或甲基丙烯酸甲酯与含氮氧稳定自由基的单体进行原子转移自由基共聚合 ,研究了共聚合反应的条件及动力学 ,成功地合成出侧链含TEMPO基团的氮氧稳定自由基聚合大分子引发剂 .大分子引发剂的结构通过核磁共振谱图进行确证 ,并对共聚合反应的历程进行了探讨     

用稳定自由基聚合及光引发聚合制备嵌段共聚物

介绍了稳定自由基聚合的反应原理、引发剂设计，以及用稳定自由基聚合制备嵌段共聚物的几种方法：连续加料法、双官能团引发剂法和一步法。对于光引发聚合的原理及硫自由基的稳定性对聚合反应的影响也进行了讨论。     

大分子单体及其规整接枝共聚物

论述了通过活性阴离子聚合、活性阳离子聚合、基团转移聚合、自由基聚合、缩聚等途径合成各种大分子单体,论讨了大分子单体的表征,并结合自己的工作综合介绍近年来大分子单体共聚的进展及其规整接枝共聚物的纯化和特性。     

含二苯酮基的大分子光敏引发剂的研究进展

简要介绍含二苯酮基的大分子光敏引发剂的合成制备、引发聚合机理及应用方面的研究进展情况。     

利用大分子单体技术合成接枝共聚物

大分子单体和小分子共单体共聚是合成接枝共聚物的重要途径之一。本文综述了大分子单体通过各种聚合方式(自由基共聚、离子型共聚、配位共聚、基团转移共聚和逐步共聚)和普通小分子单体的共聚反应,详细讨论了大分子单体和小分子单体的自由基共聚反应动力学,并简要介绍了接枝共聚物的应用背景。     

以环糊精为端基或核的大分子

综述了以环糊精为端基的线形大分子和以环糊精为核的星型大分子的合成技术及功能。现有研究表明其合成方法主要以可控/＂活性＂自由基聚合、活性阴离子聚合为主。以环糊精为端基和以环糊精为核的大分子作为一类功能型聚合物,兼具了环糊精分子与聚合物母体的功能及特点,可在一定条件下实现对客体分子的包合,增强生物相容性及高效的基因传递能力...     

光聚合制备PVC大分子引发剂及两亲接枝共聚物

利用UV光照自引发、双异丙基硫杂蒽酮(BIITX)和异丙基硫杂蒽酮(ITX)引发氯乙烯(VC)聚合得到含缺陷结构或/和ITX残基的PVC.考察了不同引发方式时单体浓度、光强、反应时间和温度对单体转化率、产物分子量及其分布的影响,UV-Vis、1H-NMR和FTIR分析表明所得PVC含缺陷氯或/和ITX残基.以此PVC为大分子引发剂(缺陷结构和ITX残基为引发点),50℃下有效引发了甲基丙烯酸二甲氨基乙酯(DMAEMA)聚合,获得了PVC-g-PDMAEMA共聚物.相比起始PVC,接枝共聚物分子量稍有提高,PDI下降.1H-NMR和FTIR分析证实了接枝共聚物的形成,接枝共聚物在水(pH=3)中组装形成了稳定核-壳结构胶束,显示其具有两亲性.     

可逆加成-断裂链转移自由基聚合研究进展

RAFT(Reversible addition-fragmentation chain transfer,可逆加成-断裂链转移)自由基存在链增长自由基与链转移剂(RAFT试剂)之间的可逆蜕化转移,现已广泛应用于聚合物分子结构设计及众多功能高分子材料的合成,受到众多高分子研究者的关注,是一种发展较快的可控/活性聚合技术.本文在简要介绍了RAFT聚合发展历程基础上,综述了RAFT聚合反应机理,RAFT试剂的结构及其对聚合性能的影响,RAFT试剂与单体的匹配性,RAFT聚合实施方法等.同时也对RAFT聚合反应的发展进行了展望.     

Poly[(N-Acetylimino)ethylene] Macromonomers with Maleic Moieties in the Dispersion Copolymerization with Styrene

Three different poly(N-acetyliminoethylene) (PNAI) macromonomers containing maleic acid moieties were tested as stabilizers for the preparation of polymer microparticles by dispersion polymerization in a polar media (alcohol/water). A comparative study on the effect of various factors, such as initiator nature and solvency of the reaction medium, on system stability and particle characteristics was performed. Styrene was used as the main monomer and ethanol, isopropanol and 2-butanol as organic solvents. Chemical and photochemical techniques were applied as initiation routes. The photoinitiators allow the synthesis of microparticles with low diameters and narrow size polydispersity in a high yield. The polymerization duration was significantly improved as compared to the methods available in the literature.     

无机中空球壳材料的制备方法

中空球壳材料具有低密度、高比表面积、高的稳定性和表面渗透性的特点,使其在化学、生物技术、材料科学领域具有极其广泛的应用前景,如用作微胶囊的缓释。还可用于药物疏运、轻质填料、形状选择吸收剂和催化剂等。本文就近几年来无机中空球壳材料的制备方法进行了综述。     

Macromonomers and coordination polymerization

The present work discusses the synthesis of well-defined comb-shaped polymers or graft copolymer structures based on coordination (co)polymerization of macromonomers. Polystyrene macromonomers with various polymerizable entities were synthesized first by induced deactivation reactions. The homopolymerization of these macromonomers in the presence of selected early or late transition metal catalysts was examined. Comb-shaped polymers could be obtained over a large range of DP values. The results were compared to those obtained by anionic homopolymerization. Some results on the copolymerization of these PS macromonomers with ethylene in the presence of VERSIPOL^TM type catalysts were presented.     

Synthesis and Characterization of Surfactant PEG Macromonomers with Fluorocarbon End‐capped Groups and its Copolymers

Fluorocarbon (R_F) or hydrocarbon (R_H) end‐capped PEG macromonomers were prepared by coupling method. Several factors mat affect the synthesis were studied and optimum condition was obtained. The critical micelle concentrations (CMC) of these macromonomers were determined by fluorescence method. A new type of fluorocarbon‐containing hydrophobically modified alkali swellable/soluble copolymers were obtained by copolymerization of R_F or R_H alkyl endcapped PEG macromonomers with acrylic acid in organic solvent The preliminary researches on viscosity property of these copolymer solutions were conducted under different conditions, such as various macromonomer content in the copolymer, polymer concentration, shear rate, pH value and temperature. All the results proved that there existed a very strong hydrophobic association among hydrophobes in these copolymer solutions.     

Synthesis of Hydroxy-Functional PMMA Macromonomers by Anionic Polymerization

Living anionic polymerization has been utilized to synthesize hydroxy end-functionalized PMMA macromonomers with styryl or allyl functionalities as the polymerizable end-groups. Protected hydroxy-functionalized alkyl lithium initiators have been used to initiate anionic polymerization of MMA. Subsequently the living chains with protected hydroxyl function have been terminated using 4-vinylbenzyl chloride (4-VBC) or allyl methacrylate (ALMA) to form α-hydroxy-ω-styryl and α-hydroxy-ω-allyl PMMA, respectively. These protected hydroxy-functionalized PMMA macromonomers have been characterized by GPC and ¹H-NMR. Termination using 4-VBC led to 50% functionalization, whereas that using allyl methacrylate led to 100% functionalization of the hydroxy-PMMA.     

Preparation of block copolymer by atom transfer radical seeded emulsion polymerization

Poly(i-butyl methacrylate)-polystyrene block copolymer was successfully prepared in an aqueous medium by two-step atom transfer radical polymerization (ATRP), mini-emulsion- and seeded-ATRP, in which ethyl 2-bromoisobutyrate/CuBr/4,4-dinonyl-2,2-dipyridyl initiator system was used. The block copolymer had narrow molecular weight distribution (Mw/Mn=1.1) and the number-average molecular weight measured by gel permeation chromatography agreed with the calculated value.Part CCXLVIII of the series Studies on Suspension and Emulsion     

Preparation and characterization of a novel fluorinated acrylate resin

The novel fluorinated acrylate resin was successfully prepared by solution polymerization of 2-(perfluoro-(1,1-bis-isopropyl)-2-propenyl)oxyethyl methacrylate (POMA) with butyl acrylate (BA), methyl methacrylate (MMA) and methacrylic acid (MAA) initiated by AIBN in the co-solvents of ethyl acetate, butyl alcohol and toluene. POMA was synthesized from the intermediate perfluoro nonene and 2-hydroxyethyl methacrylate as the staring reactants. Films of the novel fluorinated acrylate resin were prepared by coating the resin directly on the clean glass sheet and allowed to dry at room temperature. The characteristics of the film such as hydrophobicity, glass transition temperature and thermal stability were characterized with the contact angle, differential scanning calorimetry and thermo-gravimetric analysis respectively. The structure of the novel fluorinated acrylate resin was investigated by Fourier transform infrared (FTIR) spectrometry. The influences of the fluorine content on the performance of the acrylate resin were studied. Results show that the hydrophobicity, chemical resistance, glass transition temperature and thermal stability of the acrylate resin are improved when the fluorinated monomer is introduced to copolymerize with other monomers. However, the hydrophobicity of the fluorinated acrylate resin is improved slightly via annealing.     

基于RAFT活性自由基聚合的具有一定立构规整性的聚丙烯腈合成

运用RAFT活性自由基聚合方法探索了具有一定立构规整性的聚丙烯腈的合成。合成得到RAFT聚合的链转移剂MESA,并以1 H NMR进行了表征;以MESA作为链转移剂、碳酸乙烯酯为溶剂,在单体浓度为0.80 M、60℃、原料配比[AN]0/[MESA]0/[AIBN]0为2500∶5∶1的聚合条件下,成功合成出较高分子量(Mn=5.60×104g/mol)、窄分子量分布(PDI=1.15)的聚丙烯腈;进一步在各单体浓度的RAFT聚合中,加入单体摩尔量3%的AlCl3,得到聚丙烯腈数均分子量为6.1×104~6.5×104g/mol,全同立构组成为mm=32.1%~32.6%,聚合产物分子量分布宽度介于1.31~1.38之间,从而实现了在RAFT活性聚合体系中通过Lewis酸的作用合成得到具有一定立构规整性的聚丙烯腈。     

用引发转移终止剂制备嵌段和接枝共聚物

介绍了引发转移终止剂(Iniferter)的概念及其引发“活性”自由基聚合的原理。综述了Iniferter在制备ABA型三嵌段共聚物和接枝共聚物中的应用和发展。     

Macromolecular Architecture Based on Anionically Prepared Poly(ethylene oxide) Macromonomers

Synthesis of poly(ethylene oxide) (PEO) macromonomers carrying a methacyloyl group in one end, and N, N-dimethyl amino, thiophene, styryl and vinyl ether functional groups in the other end was desribed. The general synthetic strategy is based on the living anionic polymerization of ethylene oxide initiated with functional potassium alcoholates, followed by reaction with methacyloyl chloride. These macromonomers were further utilized in various macromolecular architectures through via concurrent or selective thermal free radical, oxidative and photoinitiated free radical and cationic polymerization methods. The use of this synthetic route to prepare graft copolymers possessing completly and perfectly alternating PEO side chains using charge-transfer-complex polymerization was also demonstrated.