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1.
聚氯乙烯断面特征区及粗糙度与断裂能的关系   总被引:2,自引:0,他引:2  
罗筑  徐涛  于杰  刘一春 《高分子学报》1999,118(4):494-497
以往对聚合物材料的断面粗糙度与力学性能关系的研究主要是针对断面总体粗糙度进行的,忽略了断裂的不同阶段及不同的断裂机制在断面上产生的相应的特征区对力学性能参数的影响,导致如文献[1]、[2]中得出的粗糙度参数与断裂能耗间的数据关系存在较大的分散性.本文...  相似文献   

2.
韧性聚合物材料断面分维与断裂韧性吕素平,漆宗能(中国科学院化学研究所工程塑料国家重点实验室,北京,100080)关键词分维,断裂韧性,聚合物,微裂纹,剪切带利用分形几何定量描述材料断面的粗糙特征[1-4]为建立断面形貌与材料韧性间的定量关系提供了可能...  相似文献   

3.
聚醚醚酮(PEEK)自工业化以来[1],由于其优异的性能已在机械、航天等领域得到广泛应用.各种聚芳醚酮类聚合物相继被开发出来.但以亲电缩聚路线制备聚醚醚酮醚酮(PEEKEK)的报道较少[2].本文以二苯醚和4-氟苯甲酰氯为主要反应试剂,采取付氏酰基化...  相似文献   

4.
含间位聚醚酮醚酮酮的合成与结晶   总被引:2,自引:0,他引:2  
聚芳醚酮类聚合物因其综合性能优异而在高技术领域得到广泛应用.这些高聚物的主链大都为全对位连接,使其熔点较高以至加工难度增大.如果在聚合物主链中引入间位结构,则可在对玻璃化转变温度影响较小的情况下降低熔点来改善加工条件[1].含间位聚醚酮醚酮酮(PEKEKmK)也是其中一种.本文主要研究PEKEKmK的合成、基本物性与结晶行为.样品的合成与制备:单体4,4′双(对苯氧基)二苯甲酮按文献[2]方法合成.聚合物参照文献[3]合成.将粉末样品在油压机上熔融后快速取出投入冰水中淬火得无定形样品,或将熔融…  相似文献   

5.
研究了在35±0.1℃、离子强度0.5mol/L(KCl)条件下,甲酸根、乙酸根、丙酸根和丁酸根分别催化Cu(Ⅱ)离子与四溴化间-四(N-乙酸甲酯基-3-吡啶基)卟啉(H2Tβ-N-ACMspyPBr4)的反应动力学及其机理,该类反应对卟啉和Cu(Ⅱ)离子均为一级反应,反应动力学方程为:d[CuP^4+]/dt=k{1.0+b[A^-])/(1.0+K3,4.[H^+]^2}[Cu^2+][P]T  相似文献   

6.
色谱保留值与流动相组成间关系的研究一直是色谱工作者关心的课题[1,2].灰色模型对于处理具有不确定关系的两因素间的关系问题具有独到之处,在容量因子(k)与流动相组成(φ)关系的研究方面已得到了应用[3~8].传统GM(1,1)模型将k与φ之间的关...  相似文献   

7.
聚醚酮酮/含萘环聚醚砜醚酮酮无规共聚物的合成与性能   总被引:11,自引:0,他引:11  
聚芳醚酮作为一类耐高温特种工程塑料,具有优异的热、电、机械性能,已被广泛应用于电子电器、宇航、原子能工程等高科技领域.对于聚醚醚酮(PEEK)及其改性的研究已有很多报道[1~4],然而有关主链含萘环的聚芳醚酮的报道较少[5].前文[6]采用亲电取代路...  相似文献   

8.
PPV-PDMeOPV共聚物发光性质的实验和理论研究   总被引:3,自引:0,他引:3  
具有优良电致发光性能的有机聚合物材料的研制及其发光性能和应用的研究是90年代新兴的高科技领域.聚对苯乙炔[Poly(p-phenylenevinylene),缩写为PPV,又称聚苯撑乙烯]是这一领域最先研制出来的具有代表性的材料[1,2].为改变PP...  相似文献   

9.
C60接枝聚(N-乙烯基咔唑)的合成、表征及光电导性能   总被引:2,自引:0,他引:2  
自从C60被发现和被制备出来以后,其特殊的结构和独特的物理和化学性质受到各研究领域学者的广泛青睐.聚(N-乙烯基咔唑)(PVK)体系经 C60掺杂后光电导性能有很大幅度提高.但掺杂体系不稳定,因而限制了对该类材料的应用.为了克服这种缺点,我们尝试用各种简单的方法把C60化学键合到高分子链中,制备具有光电导性能的C60高分子衍生物. 最近,唐本忠[1]和 Patil[2]等分别用常规的自由基聚合方法,将C60接枝到聚合物分子主链上,我们已研究了不含导电高分子的C60共聚物的光电导性能[3],本文采用…  相似文献   

10.
含萘环聚醚砜醚酮酮的合成与表征   总被引:4,自引:1,他引:4  
聚芳醚酮是一类综合性能优异的新型热塑性高分子材料,在高科技领域中获得了广泛的应用[1,2],研制新型的聚芳醚酮是目前十分活跃的课题[3~7].本文在亲电缩聚合成聚醚酮酮(PEKK)的基础上[8],利用合成的新单体—4,4-二(β-萘氧基)二苯砜(B...  相似文献   

11.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

12.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

13.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

14.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

15.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

16.
Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.  相似文献   

17.
用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.  相似文献   

18.
19.
A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu0 as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than CuI in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).  相似文献   

20.
(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C60, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.  相似文献   

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