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吡啶桥联的聚酰亚胺的合成与性能研究 总被引:2,自引:0,他引:2
以3,4-二甲基苯乙酮与3,5-双(三氟甲基)苯甲醛为原料,通过Chichibabin反应制备了吡啶桥联的四甲基化合物,该化合物再经氧化、脱水反应制备了主链含有吡啶环、侧链带有双三氟甲基取代苯侧基的新型含氟芳香族二酐单体,2,6双(3′,4′-二羧基苯基)-4-(3″-,5″-双三氟甲基苯基)吡啶二酐(6FDAPA).FT IR、NMR、质谱以及元素分析等测试结果表明,6FDAPA的结构与预期的相符.利用6FDAPA与另外一种不含氟的二酐单体2,6双(3′,4′二羧基苯基)4苯基吡啶二酐(DAPA)分别与含氟二胺单体,1,4双(2三氟甲基4氨基苯氧基)苯(6FAPB)通过两步热亚胺化法制备了两种聚酰亚胺(PI)薄膜.测试结果表明,6FDAPA6FAPB(PI2)与DAPA6FAPB(PI1)相比具有相近的耐热性能,玻璃化转变温度为280℃,起始热分解温度为580℃、700℃时的重量保持率64.5%.同时PI2具有更为优良的透光性,紫外可见光谱(UV Vis)测试表明,PI2与PI1薄膜在450nm处的透光率分别为85.7%与69.4%. 相似文献
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新型含氟耐高温聚吡咙--合成与性能研究 总被引:3,自引:0,他引:3
通过改进的Chichibabin反应合成了主链含有吡啶单元的新型含氟四胺单体 ,2 ,6 双 (3′ ,4′ 二氨基苯基 ) 4 (3″ ,5″ 双三氟甲苯基 )吡啶 (6FPA) .利用 6FPA与芳香族二酐单体 3,3′ ,4 ,4′ 二苯醚四羧酸二酐 (ODPA)通过两步热环化工艺制备了新型聚吡咙 (Polypyrrolone ,PPy)化合物 .对其所进行的各种性能测试结果表明 ,这种主链含有刚性吡啶结构、侧链带有含氟取代基的芳杂环高分子材料不仅保持了其固有的耐热性能 ,而且具有优良的成膜性能与耐水解性能 .例如其起始热分解温度为 5 5 8℃ ,失重 10 %温度为 5 91℃ ,72 0℃时的残余重量百分数为 6 8% ,玻璃化转变温度为 318℃ .PPy薄膜在 10 %NaOH水溶液中水解 7天仍具有良好的耐热性能与柔韧性 . 相似文献
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以自制的侧基含溴的聚酰亚胺为大分子引发剂,2,2'-联吡啶/氯化亚铜为催化体系,通过原子转移自由基聚合(ATRP)反应,引发甲基丙烯酸三氟乙酯(TFEMA)和甲基丙烯酸2-(三甲基硅氧基)乙酯(HEMA-tms)共聚,制备了以聚酰亚胺为主链的分子刷,聚酰亚胺-接枝-聚(甲基丙烯酸三氟乙酯-共-甲基丙烯酸2-(三甲基硅氧基)乙酯),(PI-g-P(TFEMA-co-HEMA-tms)).对其中甲基丙烯酸2-(三甲基硅氧基)乙酯进行水解得到侧链含羟基的聚酰亚胺分子刷(PI-g-P(TFEMA-co-HEMA)),最后通过羟基与氯磷酸二乙酯反应,得到含亚磷酸酯基团的聚酰亚胺分子刷(PI-g-P(TFEMA-co-HEMA-P)).利用核磁共振氢谱(1H-NMR)、红外等方法,表征了所合成分子刷的结构.利用示差扫描量热法(DSC)、热失重分析(TGA)研究了聚合物分子刷的热性能.根据TGA计算出的分子刷组成与1H-NMR计算结果能较好的吻合. 相似文献
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合成了一系列新型含氟耐高温、低介电常数聚酰亚胺 (PI)材料 ,并对其进行了热性能、电性能等方面的测试 .结果表明 ,这类分子结构中含吡啶环单元的材料可保持PI固有的耐热性能 ,其在氮气下的热分解温度为 5 4 5~ 6 0 1℃ ;而侧链的双三氟甲基取代结构一方面使分子具有较高的氟含量 ,另一方面增大了分子的自由体积 ,这两方面的共同作用使得这类材料具有优良的介电性能 ,其介电常数为 2 86~ 2 91;击穿电压为15 0 4~ 197 3kV mm . 相似文献
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羟丙基三甲基氯化铵壳聚糖制备的可控性研究 总被引:5,自引:0,他引:5
用壳聚糖与缩水甘油三甲基氯化铵反应制备羟丙基三甲基氯化铵壳聚糖,所得产物的结构受壳聚糖分子量和脱乙酰度、反应温度、反应时间、壳聚糖与缩水甘油三甲基氯化铵投料比的影响。实验结果表明:随着反应温度升高,羟丙基三甲基氯化铵壳聚糖的取代度增加,在70~80℃达最大;反应时间增加,取代度增加,产物分子量降低。缩水甘油三甲基氯化铵与壳聚糖比例达3:1前取代度随比例升高而增加。脱乙酰度和分子量越大的壳聚糖其季铵盐取代度越高。控制反应温度在30~90℃,反应时间3~10h,投抖比为1:1~4:1,可以得到取代度15%~909/6,分子量1万到100万的羟丙基三甲基氯化铵壳聚糖。 相似文献
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含二茂铁核的硅有机衍生物的合成 总被引:2,自引:0,他引:2
合成了一系列含二茂铁核的硅有机衍生物.试图从环戊二烯基三甲基硅烷与FeCl2在二乙胺存在下制取1,1'-双(三甲基硅烷基)二茂铁,由于Si-C键的断裂,未获预期产物而得二茂铁. 为了合成双有机硅基二茂铁,采用了两种方法.方法之一是从1,1'-二茂铁二钠与相应的三烷基氯硅烷反应制得1,1'-双(三甲基硅烷基)二茂铁、1,1'-双(三丁基硅烷基)二茂铁和1,1'-双(二甲基苯基硅烷基)二茂铁.为了取得单取代硅烷基二茂铁,采用二茂铁锂,但一般得单和双取代衍生物的混合物,它们很难分离;如减少有机氯硅烷用量,则可得纯的单取代乙烯基二乙基硅烷基二茂铁.另一方法是将三甲基-γ-氯丙基硅烷的格氏试剂与二乙酰基二茂铁反应制得含二茂铁核的双叔醇. 相似文献
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Keiji Kabeta Shigeru Wakamatsu Takafumi Imai 《Journal of polymer science. Part A, Polymer chemistry》1996,34(14):2991-2998
Network methylethoxypolysilanes containing various substituents such as hexyl, phenyl, ethylene, hexamethylene, phenylene, and thiophene groups were prepared by a disproportionation reaction of 1,1,2,2-tetraethoxy-1,2-dimethyldisilane in the presence of the corresponding substituted alkoxysilanes. The reaction was considered to proceed via a silyl anion mechanism. The silyl anion produced from a disilane or a higher homologue attacked the alkoxysilane, and that caused the alkoxysilane moiety to be introduced into the polysilane. The amount of incorporated substituents varied from 3 to 29% of all organic substituents, depending on which alkoxysilane was reacted. The electrical conductivities of some polysilanes were measured, and the polymer with thiophene groups was found to show relatively higher conductivity of 10−5 Scm−1 after iodine doping. © 1996 John Wiley & Sons, Inc. 相似文献
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Langmuir–Blodgett (LB) films were prepared from poly(methylphenylsilane) bearing electron acceptor π-conjugated substituents. The small limiting area (0.078 nm2) per one repeating unit of polysilane (PSi) in monomolecular film and the large thickness of the film (6 nm) suggest that the polymer chains are not fully spread on water surface. The electrical and photoelectrical properties of Al/LB film/Au sandwich cells containing various numbers of the polysilane layers were studied. Holes were transported from the Al electrode through the LB film to the Au electrode when the light was absorbed by the polysilane. The highest photovoltaic effect occurred in the first monolayer of polysilane at the Al contact. The cell resistivity and the photovoltage were decreased by parallel conductance of defects in the films consisting of small numbers of PSi layers. 相似文献
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本文介绍了聚硅高分子的合成方法、紫外吸收、光敏性、导电性等一系列特殊性质,聚硅烷高分子的化学反应以及聚硅烷材料的应用. 相似文献
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The meso- tetraarylporphyrin has been anchored to styrene- divinylbenzenecopolymers by reaction of meso- tetra (4-hydroxylphenyl ) porphyrin with chloromethylatedresin under mild condition. A number of polymer transition metal complexes have beenprepared with the polymer ligand and metal salts. The polymeric ligand and its complexeshave been characterized by electronic spectra, and vibrational spectra. Cyclohexene can behydrogenated with the polymeric porphyrin palladium complex(P-THPPPd) as catalyst,and its catalytic activity was influenced by the polarity of solvents, the contents of water inethanol or reaction temperature. However, its catalytic activity was lower for nitro groups,carbonyl groups and olefins with steric hindrance substituents, and showed no activity foraromatic rings under these conditions. 相似文献
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Zhengcheng Zhang Leslie J. Lyons Ryan West Khalil Amine Robert West 《Silicon Chemistry》2007,3(5):259-266
New comb polysiloxanes with mixed substituents were synthesized by hydrosilylation of PMHS with 4-allyloxymethyl-[1,3]dioxolan-2-one
and tri(ethylene glycol) allyl methyl ether (AMPEO3). The effect of the incorporation of carbonate groups on ionic transport, viscosity and thermal properties has been investigated.
When doped with lithium bis(trifluorosulfonyl) imide, LiTFSI, the mixed substituted polysiloxane polymers with varying carbonate
content all exhibited conductivity higher than those for the polysiloxanes with pure carbonate or pure oligoethyleneoxy substituents.
The maximum ambient conductivity in this series was 1.62× 10−4 S/cm, occurring for the polymer containing 8.5% polar carbonate groups at a doping level of EO/LiTFSI = 15. The impedance
measurement results showed that polymers containing larger amounts of carbonate groups exhibited lower conductivity, probably
because of their increased viscosity and higher glass transition temperature. The conduction mechanism for these new comb
polymers obeys free volume theory, as indicated by conductivity data fit to the VTF equation.
We dedicate this paper to Professor Dick Jones, polysilane pioneer and valued friend. 相似文献