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聚乙烯醇是透氧最慢的聚合物之一,而聚二甲基硅氧烷透氧极快。  相似文献   

3.
自1990年Burroughes等首次报道聚对亚苯亚乙烯的电致发光以来,由于电致发光高分子材料在平面显示(特别是大面积显示)方面具有其他显示材料难以比拟的优势,因而近年来受到人们的广泛关注,在合成方法、加工性能、发光颜色的调控以及器件性能等多方面取得显著进展,不  相似文献   

4.
A novel kind of copolymer with ABA-type block structure was synthesized by anionic ring-openingpolymerization of β-butyrolactone (β-BL) in the presence of a PEG-based dicarboxylates as macroinitiators which wereprepared by the esterification of aliphatic cyclic anhydride and poly(ethylene glycol) (PEG) oligomers (M_n=2000, 4000 and6000) and conversion of potassium dicarboxylates. The resultant copolymers as well as the intermediates were characterizedby IR,~1H-NMR and GPC.  相似文献   

5.
Poly(methylene terephthalate) (PMT) and poly(ethylene terephthalate) (PET) were synthesized by triethylamine-mediated reactions of terephthalic acid and dihalomethanes or 1,2-dihaloethanes, respectively. Reactions with chloro compounds required longer reaction times and higher temper-atures than those with bromo. Copolymers were synthesized by using proportionate amounts of dihalomethane/1,2-dihaloethane mixtures. Copolymer compositions were determined by inte-grations of relative areas of methylene and ethylene 1H NMR peaks. Mn values were determined from 1H NMR end group signals. Mole fraction feed is linearly related to CH2/CH2CH2 incorporation into copolymer products. Mechanisms are proposed to explain results.  相似文献   

6.
以异溴丁酸羟乙酯为引发剂、溴化亚铜和2,2′-联吡啶为催化剂和配体,引发丙烯酸琥珀酰胺酯(NAS)进行原子转移自由基聚合,得到的聚丙烯酸琥珀酰胺酯(PNAS)的分子量可以通过配比和转化率预测.进一步与单端氨基苯胺四聚体(TA)在50℃下反应,得到的聚合物用1H-NMR和FT-IR的测试,结果表明,当TA/NAS的摩尔比为3∶1时,PNAS上的琥珀酰胺酯可以完全被取代,从而得到侧链为苯胺四聚体的导电高分子.聚合物的结构和分子量以及分布用核磁共振氢谱、FT-IR和GPC进行表征;电化学性质用循环伏安法进行了测试.  相似文献   

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聚苯基膦酸双酚A酯的合成与表征   总被引:5,自引:0,他引:5  
聚苯基膦酸双酚A酯的合成与表征唐旭东陈晓婷王玉忠杨科珂王波(四川联合大学化学系成都610064)吴大诚(四川联合大学轻纺学院成都610065)关键词聚膦酸酯,阻燃剂,熔融缩聚,热性能聚膦酸酯类化合物是一类重要的磷系阻燃剂[1~3],与传统的非聚...  相似文献   

9.
聚二乙烯基苯微球的合成及其表征研究   总被引:5,自引:0,他引:5  
采用分散聚合方法制备了聚二乙烯基苯微球 ,研究了引发剂、稳定剂、单体 溶剂比例和溶剂种类对微球粒径及其分布的影响 ,在适当的条件下可以得到平均粒径较大、粒径分布较窄的微球 .用红外光谱法研究了聚合物微球内稳定剂、悬挂双键以及对位和间位二乙烯基苯含量随聚合过程的进行发生的变化 .测得的微球TG曲线表明 ,聚合物微球具有良好的热稳定性 .  相似文献   

10.
超支化聚(胺酯)的分子设计及其制备   总被引:21,自引:1,他引:21  
以丙烯酸甲酯和二乙醇胺为原料由Michael加成反应制得N ,N 二羟乙基 3 胺基丙酸甲酯单体 ,再用“准一步法”和“发散法”使之与 1 ,1 ,1 三羟甲基丙烷 (核 )反应合成一种新型超支化聚 (胺 酯 ) .以核磁共振和元素分析方法对N ,N 二羟乙基 3 胺基丙酸甲酯单体的分子结构进行了表征 .GPC测定表明合成的超支化聚 (胺 酯 )分子量分布窄 ,具有单分散性 ;粘度小于同分子量的线形分子 ;耐热性能较好 ,失重温度高于2 0 0℃ .  相似文献   

11.
ABSTRACT

Transparent organic/pre-ceramic composite films of poly(methyl methacrylate) [PMMA] and perhydropolysilazane [PHPS] were synthesized by blending poly(methyl methacrylate-co-2-hydroxyethyl methacrylate) [P(MMA-co-HEMA)] random copolymers and PHPS. In the blend films, P(MMA-graft-PHPS) graft copolymers were formed, PMMA and PHPS were microscopically phase-separated in the solid state. Morphology of the microphase separation was investigated by transmission electron microscopy by changing HEMA content of the random copolymers and blend ratio of PHPS to HEMA. To convert PHPS to silica glass, the blend films were calcinated at 100°C. The morphology of the microphase separation of the films was not changed by the calcinations; the calcinated films were transparent. When the molar content of HEMA of P(MMA-co-HEMA) and the molar content of PHPS to HEMA in feed were 14.5% and 150%, respectively, the morphology was well ordered lamellae of PMMA and silica.  相似文献   

12.
The organic salts as initiators [A~+B~-:Ph_3C~+ClO_4~-, Ph_3C~+SbCl_6~-, (-)Sp~+ClO_4~- and(-)(Sp)_2~(+3)(ClO_4)_3] and catalysts [A~+B~-:(+)CSA, A~+B~-:Ph_3C~+(+)CSA~- and(-)Sp~+(+)CSA] are prepared and characterized by specific rotation. The asymme-trically stereoselective induction of the initiators and catalysts in the polymerization ofN-vinylcarbazole is in an order of A~+B~->A~+B~->A~+B~-. The specific rotations ofobtained poly (N-vinylcarbazole ) (PVCZ) generally are in accordance with mentioned order.  相似文献   

13.
聚合物离子交换膜是聚合物电解质燃料电池的重要组成部分,同时也广泛地应用于电渗析、电解等电化学过程中,其性能优劣直接决定了过程的效果[1~3]。九十年代初期,随着Dupont的Nafion膜在聚合物电解质燃料电池中的成功应用,已使燃料电池技术取得重大进...  相似文献   

14.
A novel small band-gap conjugated polymer - poly [(3-acetylpyrrole-2, 5-diyl)(4-dimethylaminobenzyliene)(3 -acetylpyrrolequinodimethane-2, 5-diyl)] (PAPDMABE) - and its precursor were synthesized by a simple method andcharacterized by ~1H-NMR, FT-IR, TGA and UV-VIS. The polymer can be dissolved in strong polar solvents such as DMSO,DMF or NMP. The band-gap energy of PAPDMABE was found to be 0.95 eV. The conductivity of doped products withiodine falls in the range of a semiconductor.  相似文献   

15.
<正> 关于烯烃与SO_2交替共聚合,在三十年代Marvel和Staudinger等已开始研究,最近又有这方面的总述性文章报道。 关于环己烯与SO_2交替共聚合,Marvel等先以H_2O_2为引发剂进行本体聚合,以后,又在体系中引入一定量的乙醇,在25-30℃温度下反应24小时经乙醚沉淀得到收  相似文献   

16.
超支化聚硅氧基硅烷的合成及其表征   总被引:1,自引:0,他引:1  
基于线性聚硅氧烷在国防、能源和化工等领域的广泛应用,具有新颖拓扑结构和大量功能性端基的超支化聚硅氧烷引起了国内外科学工作者的广泛兴趣[1~7].到目前为止,主要是采用水解缩聚的方法合成超支化单体,在铂系催化剂存在下进行硅氢加成反应或者在碱催化剂存在下进行质子转移聚合制备超支化聚合物[8~12].然而,以上合成超支化聚硅氧烷的方法仍然存在一定的不足.例如,水解法步骤繁琐,通常在第一步反应结束后需要多次除水,并继续滴加单氯硅烷以得到完全取代的大单体;同时多官能度单体容易水解自缩聚,产生A2B4或A3B6等副产物,不仅不利于结构控…  相似文献   

17.
聚酯酸酐的合成与表征   总被引:3,自引:0,他引:3  
聚酸酐具有优良的表面溶蚀性能,作为药物控释体系材料得到广泛的应用.以对(2 羟基 乙氧基)苯甲酸和对(2 甲基 2羟基 乙氧基)苯甲酸分别与丁二酸酐,顺丁烯二酸酐和丁二酰氯反应得到六个含有酯基的新型二元酸单体,经熔融聚合得到聚酯酸酐.单体和聚合物经IR,1H NMR和元素分析等表征.研究了催化剂对聚合物结构的影响.  相似文献   

18.
聚酰胺-胺的合成与表征   总被引:1,自引:0,他引:1  
<正> 1970年以来,Ferruti等发表了一系列文章关于聚酰胺-胺(PAA)的研究。PAA是一类由伯胺或双仲胺和双丙烯酰胺通过氢移位聚合生成的新聚合物:  相似文献   

19.
Abstract

Various sulfides are easily oxidized selectively to the corresponding sulfoxides in quantitative yields by iodosylarene (ArIO) catalyzed by metalloporphyrin (TPPM(III)Cl (M [dbnd] Fe, Mn)). The oxidation system is demonstrated to be a possible model for monooxygenase in the study of the stereochemistry of these sulfoxides. Metalloporphyrin-iodosylarene can initially equilibrate with the oxometalloporphyrin (TPPM(V)=O·Cl) formed in situ. The initial process may involve one-electron transfer from the sulfide to the intermediate oxometalloporphyrin followed by coupling of two resulting charged products, and/or nucleophilic attack of sulfide on oxometalloporphyrin oxygen. The overall reactions are depicted by paths with different electron demands from the results of Hammett plots.  相似文献   

20.
This paper is concerned with the synthesis of poly (ether-urethane) with pendant amino groups. The copolyether produced by ring opening copolymerization of tetrahydrofuran and epibromohydrin was treated with sodium azide in dimethylformamide to form azido substituted copolyether. The poly (ether-urethane) made from it was subjected to reduction reaction to convert azido group to amino group. The stress-strain behavior and dynamic-mechanical properties of poly (ether-urethane) containing pendant amino groups were studied.  相似文献   

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