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1.
等规聚苯乙烯的合成及其结晶性能 总被引:2,自引:0,他引:2
用负载型钛系催化剂MgCl_2/TiCL_4,NdCl_3/AlEt_3(SN-1催化剂)在甲苯溶剂中进行苯乙烯的定向聚合,单体转化率。催化效率和产物的等规度随单体浓度增大先是提高,达到最大值后,逐渐下降,等规度最高可达98%.产物的分子量则随单体浓度增大而增大.DSC测定表明,产物中的无规物(aPS)有利于等规聚苯乙烯(iPS)结晶,但对结晶的熔点有降低作用.向产物加入更多的aPS则由于稀释效应而使iPS的结晶度线性下降.在聚乙烯(PE)/iPS共混物中,PE含量对iPS的结晶度无显著影响;但在聚碳酸酯(PC)/iPS共混物中,PC含量对iPS的结晶度影响较复杂. 相似文献
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用新合成的3-(二乙醇)氨丙基硅氧烷(DEAP)、3-(氮杂18-冠-6)丙基硅氧烷(BCP)作固定相,对二取代苯异构物进行液相色谱分离,研究流动相组成,pH值及其K ̄+离子浓度对色谱行为的影响.探讨溶质保留机理,并比较DEAP、BCP与ODS的色谱性能. 相似文献
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褐煤蜡中树脂组分的化学研究:生物标志化合物 总被引:4,自引:3,他引:1
用气相色谱-质谱联用仪对吉林舒兰褐煤蜡树脂和云南寻甸褐煤蜡树脂,进行了生物标志化合物的研究。结果指出,三萜类化合物中含有四环三萜、五环三萜、芳香五环三萜和含氧化合物,其中以C25A,B,C,D环-四芳鸟散烷和C25A,B,C,D环-四芳奥利烷含量最高,舒兰树脂中这两种化合物的含量高于寻甸树脂约10倍;无羁萜和3-氧代别桦木烷量亦以舒兰树脂占优势 相似文献
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GC/MS分析煤抽出物中的含硫多环芳香化合物 总被引:9,自引:3,他引:9
煤的索氏抽出物中的含硫多环芳香化合物(PASH)由硅胶柱色谱与配体交换薄层色谱(PdCl_2/SiO_2)两步分离,用毛细管气相色谱(FID与FPD)和色质联用仪分析其组成、结构。通过与文献的色谱保留指数相比较、质谱数据验证,鉴定出贵定煤含硫芳香化合物以三、四环结构为主,主要是二苯并噻吩及其C_1~C_3烷基取代物、苯并萘并噻吩及其烷基取代物,其它稠环含硫芳香化合物较少。 相似文献
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GMA熔融接枝EPDM的研究 总被引:10,自引:0,他引:10
以甲基丙烯酸缩水甘油酯(GMA)为接枝单体,过氧化二异丙苯(DCP)为引发剂,对三元乙丙胶(EPDM)进行了熔融接枝,在烃链上引入极性基团,以改善EPDM与极性聚合物的相容性。用差示扫描量热计(DSC)研究了GMA的聚合温度,用富里叶红外(FT-IR)、凝胶渗透色谱(GPC)对接枝产物进行了表征。实验结果表明,产物的接枝率和凝胶量可以通过反应条件(温度、时间、反应物组成及加料方式)来控制。 相似文献
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PC/PBT共混体系的研究:(Ⅱ)PC,PBT熔融共混时的相容性 总被引:3,自引:0,他引:3
采用DSC测定了一系列PC/PBT熔融共混物的Tg,结果显示PC、PBT是部分相容的两相体系,PC、PBT之间的酯交换反应有利于相容性的提高。通过对PC、PBT两相中各组分表观质量分数的计算,发现PC溶于PBT的能力要比PBT溶于PC的能力大。通过对PC、PBT相互作用参数χ12的计算,发现在所研究的范围内(PC含量为30~70%)PC、PBT之间的相互作用参数χ12略大于其临界相互作用参数(χ12)c,表明PC、PBT在熔融共混时会发生相分离,亦即形成部分相容的两相体系 相似文献
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V. A. Nikanorov V. G. Kharitonov E. V. Yatsenko D. P. Krut'ko M. V. Galakhov S. O. Yakushin V. V. Mikul'shina V. I. Rozenberg V. N. Guryshev V. P. Yur'ev O. A. Reutov 《Russian Chemical Bulletin》1992,41(8):1430-1434
From the reaction mixtures in the uncatalyzed polybromination of [2.2]paracyclophane by the action of excess Br2 in CCl4, there have been found along with the known products — 4,15- and 4,16-dibromo[2.2]paracyclophanes — two new aromatic tribromides of this series, which have been isolated in pure form: 4,12,15- and 4,15,16-tribromo[2.2]paracyclophanes. Special experiments demonstrated that the mixtures of these tribromides are formed as a result of competitive monobromination of 4,15-dibromo[2.2]paracyclophane; the 4,15,16-tribromo[2.2]paracyclophane, together with still another newly isolated isomer of this series — 4,8,12-tribromo[2.2]paracyclophane — is formed as a result of competitive monobromination of 4,16-dibromo[2.2]paracyclophane. As an explanation of the features of the orienting effect of substituents in these competing reactions, a rule was proposed: On the conventional orientation (from the electronic point of view) of entry of the bromine atom into the substituted ring (para > ortho > meta), a steric limitation is imposed on its attack in the pseudo-gem-position, owing to the bulky bromine atom that is transannularly positioned above it in the neighboring aromatic ring. The structures of all of the tribromides were established on the basis of elemental analyses, mass spectrometry, and1H NMR spectrometry (including PMR using the homonuclear Overhauser effect). The data obtained in this work indicate that the 4,12,15-tribromo[2.2]paracyclophane and 4,15,16-tribromo[2.2]paracyclophane are predecessors of the two tetrabromides previously obtained by Cram — 4,7,12,15- and 4,5,15,16-tetrabromo[2.2]paracyclophanes; and the 4,8,12-tribromo[2.2]paracyclophane is a possible predecessor of 4,8,12,16-tetrabromo[2.2]paracyclophane, which is unknown up to the present time.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1837–1843, August, 1992. 相似文献
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Elena Yu Schmidt Alexey B Zaitsev Alexander M Vasil'tsov Gilles Clavier Robert B Pansu 《Tetrahedron letters》2004,45(28):5489-5491
Rearrangement of 5-(1-vinyloxyiminoethyl)[2,2]paracyclophane, the key intermediate of the Trofimov reaction (pyrrole formation from ketoximes and acetylene), gives (120 °C, 30 min, DMSO) 2-([2,2]paracyclophan-5-yl)pyrrole in 74% yield. The intermediate 5-(1-vinyloxyiminoethyl)[2,2]paracyclophane has been synthesised in 78% yield by vinylation of the Cs-derivative of the oxime of 5-acetyl[2,2]paracyclophane with acetylene under pressure in the DMSO-n-pentane two-phase system (70 °C, 5 min). 相似文献
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Lin Lin Yasuhiro Morisaki Yoshiki Chujo 《Journal of polymer science. Part A, Polymer chemistry》2009,47(24):7003-7011
We synthesized through‐space conjugated polymers with [2.2]paracyclophane and thieno[3,4‐b]pyrazine units in the main chain by the Sonogashira–Hagihara coupling reaction. The obtained polymers were soluble in common organic solvents, and homogeneous thin films were readily obtained from the polymer solutions by spin‐coating techniques. The polymers exhibited the extension of the conjugation length via the through‐space interaction. The polymers showed orangish‐red emission with peak maxima of around 610 nm in diluted solutions and their thin films, which were derived from the thieno[3,4‐b]pyrazine moieties. The optical and electrochemical behaviors of the polymers containing pseudo‐para‐ and pseudo‐ortho‐linked [2.2]paracyclophane were identical. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009 相似文献
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L. I. Zakharkin V. A. Ol'shevskaya L. E. Vinogradova 《Russian Chemical Bulletin》1997,46(6):1158-1163
Methods for the synthesis of [2,2]paracyclophane derivatives containingo- andm-carboranyl substituents in position 4, separated from the [2,2]paracyclophane system by one or two C atoms (alcohols and
ketones) were developed. The Clemmensen reduction of a number of ketones of the [2,2]paracyclophane ando-carbonane series occurs abnormally. The reduction of 1-benzoyl-o-carboranes to the corresponding alcohols by zinc in ethanol in a neutral medium was performed for the first time.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1206–1211, June, 1997. 相似文献
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D. Yu. Antonov E. V. Sergeeva E. V. Vorontsov V. I. Rozenberg 《Russian Chemical Bulletin》1997,46(11):1897-1900
An efficient three-step synthesis of [2.2]paracyclophane-pseudo-ortho-dicarboxylic acid by dibromination of [2.2]paracyclophane, thermal isomerization of the resultingpseudopara-dibromide topseudo-ortho-isomer, followed by lithiation/carboxylation was developed. The possibility of preparation of two other novelpseudo-ortho-disubstituted carbonyl derivatives, 4-carboxy-12-(1-oxopenthyl)-[2.2]paracyclophane and di(4-carboxy[2.2]paracyclophanyl-12)ketone,
was demonstrated when an excess of lithiation reagent (4 or 10 eq.) was used in the final step.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2001–2004, November, 1997. 相似文献
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4,16-Dibromo[2.2]paracyclophane (4) is isomerised to 4,12-dibromo[2.2]paracyclophane (1) by the application of microwaves in DMF solution. 相似文献
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An exploration into the scope of Suzuki aryl cross-coupling chemistry using derivatives of 1,1,2,2,9,9,10,10-octafluoro[2.2]paracyclophane is reported. The coupling of 4-iodo-1,1,2,2,9,9,10,10-octafluoro[2.2]paracyclophane with various aryl boronic acids and boronic acid pinacol esters was successful, with the exception of very sterically demanding systems, such as mesityl. The synthesis of the previously unreported 1,1,2,2,9,9,10,10-octafluoro[2.2]paracyclophanyl-4-boronic acid is described, together with various Suzuki aryl cross-coupling reactions of this new system. Using standard Suzuki methodology, it was possible to prepare dicyclophanes bearing two octafluoro[2.2]paracyclophane units separated by both one and two benzene rings. 相似文献
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N. V. Vorontsova V. I. Rozenberg E. V. Vorontsov O. L. Tok Yu. N. Bubnov 《Russian Chemical Bulletin》2000,49(5):912-919
Stereoselectivity of allylboration of 4-formyl[2.2]paracyclophane, 4-acetyl[2.2]paracyclophane, and 4-hydroxy-5-formyl[2.2]paracyclophane
was studied and the relative configurations of the homoallylic alcohols obtained were established. Optically pure (Sp,Sc)-(+)-4-(4-hydroxy-1-methylbut-3-enyl)[2.2]paracyclophane and (Rc,Sc)-(+)-4-hydroxy-5-(4-hydroxybut-3-enyl)[2.2]paracyclophane were synthesized. The possibility of using (Sp,Sc)-(+)-4-(4-hydroxy-4-methylbut-3-enyl)[2.2]paracyclophane as a recoverable chiral auxiliary in asymmetric allylboration of
aldehydes was demonstrated.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 914–921, May, 2000. 相似文献