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1.
以含均三嗪环结构的双氟单体2,4-二(4-氟苯基)-6-苯基-1,3,5-三嗪(BFPT)与4,4’-联苯二酚(BP)和9,9-二(4-羟基苯基)芴(BHF)为共聚单体,经溶液亲核取代逐步聚合,合成了一系列主链含三芳基均三嗪环结构和双苯基芴结构线性聚芳醚(PEPs).反应过程经优化,得到的聚合物数均分子量高达6.3×104.采用元素分析、FTIR、NMR和H-H gCOSY等对聚合物结构进行表征,并对聚合物进行溶解性、示差扫描量热(DSC)、动态力学性能(DMA)、热失重(TGA)、机械性能等测试.由于双苯基芴基团的存在,聚合物的溶解性得到明显改善.当双苯基芴结构单元含量高于20%时,聚合物可溶于N-甲基吡咯烷酮(NMP)、氯仿(CHCl3)、四氯乙烷(C2H2Cl4)、和吡啶(pyridine)等极性溶剂中,同时保持了优异的耐热性.聚合物的玻璃化转变温度Tg由DSC测得在269~307℃之间,由DMA测得在269~291℃之间,且随着主链中双苯基芴结构的增加而升高.N2气氛下,PEPs的5%热失重温度超过544℃,800℃残碳率大于48%.  相似文献   

2.
在以CuCl和四甲基乙二胺(TMEDA)作为催化剂和邻二氯苯作溶剂条件下,以二-(4-乙炔苯基)-4-辛氧基苯胺(M1)和3, 6-双(乙炔基)-N-辛基咔唑(M2)作为单体,通过Glaser-Hay氧化偶联反应合成了含有咔唑和三苯胺结构单元的聚芳烃二乙炔共轭聚合物.采用红外光谱、核磁共振谱、热失重分析、紫外吸收光谱和荧光光谱等方法对聚合物进行结构表征与性能测试.所得到的聚合物都溶于普通的有机溶剂(如四氢呋喃、二氯甲烷、氯仿、甲苯等).结果表明,聚合物具有优异的热稳定性,热失重5 %时,分解温度在400℃以上;在光激发的条件下,聚合物在二氯甲烷溶液中发射蓝光.  相似文献   

3.
合成了3个侧链含不饱和基团取代的硫代双烯型镍络合物,即双[4,5-二(4'-叔丁基苄基)硫-1,3-二硫杂环戊烯]镍(2a)、双[4,5-二(烯丙基)硫-1,3-二硫杂环戊烯]镍(2b)和双[4,5-二(3'-苯基-烯丙基)硫-1,3-二硫杂环戊烯]镍(2c)以及作为参照品的一个侧链含饱和基团的硫代双烯型镍络合物,即双[4,5-二(癸基)硫-1,3-二硫杂环戊烯]镍(2d).它们的结构经1H NMR和质谱得到了表征.这些化合物在甲苯中有较好的溶解性,最大吸收波长(λmax)在1000 nm左右,而且取代基对它们最大吸收波长的位移影响很小.它们在固态聚甲基丙烯酸甲酯(PMMA)中的λmax也在1000 nm左右,且浓度较低时,吸收曲线未见有宽化的迹象.固态循环伏安的测试结果表明,苯基的引入对提高这类化合物的氧化电位有影响.热重分析(TGA)的结果表明,这类化合物失重5%的温度都在200℃以上.氙灯(300 W)照射100 min,它们的吸光度在甲苯中下降不到10%,在固态的PMMA中下降不到2%,苯基的引入有助于提高这类化合物在溶液和固态PMMA中的光化学稳定性.  相似文献   

4.
四苯醚砜双炔聚合过程及其聚合物的动态力学行为研究   总被引:3,自引:0,他引:3  
本文用扭辫分析(TBA)和红外光谱研究了双[4-(4-乙炔基苯氧基)苯基]砜(简称四苯醚砜双炔)及其聚合物的动态力学行为.TBA热谱的结果可以明显地表征四苯醚砜双炔的熔融及其低温区和高温区的化学反应特征,以及其聚合物的玻璃化转变和分解反应等物理-化学转变行为.实验表明四苯醚砜双炔聚合物的玻璃化温度Tg极大地取决于聚合条件.  相似文献   

5.
星形聚硅氧烷的热稳定性研究和结构表征   总被引:3,自引:0,他引:3  
含六苯基环三硅氮烷 (P3N)的聚硅氧烷的低温性能与普通聚硅氧烷相当 .35 0℃ ,封闭氮气中老化2 4h后 ,含P3N 聚硅氧烷的热失重比普通聚硅氧烷低 4~ 10倍 ,随聚合物含氮量增加 ,其失重呈下降趋势 ,最低失重为 1 1% .六苯基环三硅氮烷三锂盐 (P3NLi)引发环硅氧烷聚合得到的含P3N 聚硅氧烷的2 9Si NMR谱、IR谱和分子量 (GPC)与特性粘数的关系证明其具有星形结构  相似文献   

6.
以4,4'-二羟基苯基正戊酸和4,4'-二氟二苯酮为原料, 二甲基亚砜(DMSO)为溶剂, 采用亲核取代反应合成侧基含羧基的聚芳醚酮均聚物, 进一步与1-萘酚和2-萘酚接枝制备新型含萘可交联聚芳醚酮. 用核磁共振(NMR)、红外光谱(FTIR)、示差扫描量热(DSC)和热重分析(TGA)表征其结构和性能, 含萘聚芳醚酮在常用有机溶剂如N,N-二甲基乙酰胺(DMAc)、DMSO, 四氢呋喃(THF)中有良好的溶解性, 并具有很好的成膜性. DSC测试结果显示, 在170℃热处理2 h的交联聚合物的玻璃化转变温度(Tg)提高40℃. TGA数据显示接枝后的聚合物的5%热失重温度提高40~50℃, 证明其发生交联反应. 结果表明, 新型含萘可交联聚芳醚酮具有热固性树脂的耐溶剂和耐高温特性, 进一步拓宽了聚芳醚酮的应用前景.  相似文献   

7.
由3,3′-双(4-羟基苯基)苯并吡咯酮(HPP)和4,4′-二氟二苯酮经亲核缩聚合成聚芳醚酮(PEK-H),再经与环氧氯丙烷(ECH)的亲核取代反应,制得了一种含量可控的环氧侧基酚酞聚芳醚酮(PEK-HE)。 改变ECH的投料量,可调控环氧侧基在聚合物中的含量。 采用FTIR、1H NMR和TGA等技术对聚合物进行了结构表征与性能测试,并考察了经自固化后聚合物涂膜的性能。 涂膜热稳定性较固化前明显提高,5%热失重温度均在450 ℃以上。 涂膜具有优异的热性能和机械性能:耐温(350±20) ℃;冲击强度高于100 kg·cm。  相似文献   

8.
采用格氏试剂法制备了苯乙炔封端型含硅芳炔(PTPSA),并采用傅里叶转换红外光谱(FT-IR)、核磁共振氢谱(~1 H-NMR)和差示扫描量热法(DSC)表征了其结构。以PTPSA和1,3,5-三叠氮甲基-2,4,6-三甲基苯(TAMIMB)为原料,制备了新型全内炔型含硅聚三唑树脂(P-PTA3)。利用FT-IR、DSC、动态力学分析(DMA)和热重分析(TGA)研究了树脂的固化行为及热性能,通过测试凝胶时间随贮存时间的变化研究了树脂溶液的贮存稳定性。结果表明:树脂固化物的玻璃化转变温度(Tg)可达304℃,失重率5%时的温度(Td5)达330℃以上。P-PTA3树脂溶液在35℃和25℃下贮存时间分别超过20d和40d。单向碳纤维T700/P-PTA3复合材料常温下的弯曲强度为1 875MPa,弯曲模量为135.5GPa,180℃下弯曲强度保留率为75%。  相似文献   

9.
以合成的1,3,5-三(p-羟基苯基)苯(TP)、烯丙基胺和甲醛为原料,合成了一种新型的含烯丙基的三元酚型苯并噁嗪单体——1,3,5-三(3-烯丙基-3,4-二氢-2H-1,3-苯并噁嗪基)苯(tp-ala).采用核磁共振谱、傅里叶变换红外光谱、紫外-可见吸收光谱和差示扫描量热表征了tp-ala的结构和固化行为,用热失重分析、动态热机械分析和荧光光谱测试了固化物P-tp-ala的热性能及光学性能.结果表明,烯丙基的引入使P-tp-ala玻璃化转变温度高达322℃,5%的热失重温度为351℃,800℃残炭率达到61.4%,与不含烯丙基的三元酚型苯并噁嗪相比具有较好的耐热性.在233 nm激发波长下,P-tp-ala的荧光发射波长为350 nm,具有荧光性能.由于P-tp-ala中的芳香含量高,使其折射率高达1.6325,在防折射涂层方面有很好的应用潜力.  相似文献   

10.
通过分子设计, 成功合成了一种含有三苯基膦结构的二氟单体--4,4’-二氟二苯苯磷氧(BFPPO). 在碱催化条件下, BFPPO与2-双-(4-羟苯基)六氟丙烷(六氟双酚A)缩聚得到一种新型含三苯基膦结构的聚芳醚材料(6F-PAEPO). 使用FTIR,1H NMR, 31P NMR, 和16F NMR等表征手段确定了聚合物的结构, 聚合物表现出良好的热稳定性、有机可溶性、机械性能和光透过性能, 其中聚合物的玻璃化转变温度高达211℃, 空气气氛和氮气气氛下5%热失重温度分别为512℃和523℃, 聚合物薄膜的最大光透过率超过80%. 尤其, 聚合物由于主链中三苯基磷氧结构的存在, 表现出了优异的阻燃性能, 有限氧指数(LOI)达到39.9%.  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

13.
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   

14.
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   

15.
A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.  相似文献   

16.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

17.
A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.  相似文献   

18.
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   

19.
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   

20.
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   

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