共查询到20条相似文献,搜索用时 9 毫秒
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从2-氨基苯硫酚出发制备二硫代二苯胺,以此为原料与重铬酸钠在低温溶液中合成聚二硫代二苯胺,并对产物进行了红外光谱、热重、X射线、光电子能谱和扫描电镜分析表征。 相似文献
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以四(三苯基磷)钯(Pd(PPh3)4)和CuI为催化剂,在二异丙胺和四氢呋喃溶液中,采用宽能带的1,4-二乙炔基-2,5-二(十二烷氧基)苯(PE)和窄能带的4,7-双(5′-溴-2′-呋喃)-2,1,3-苯并噻二唑(FBT)合成了一系列新型聚芳炔。长链烷氧基的存在使得此类聚合物在常用的有机溶剂中具有较好的溶解性和成膜性。通过对上述聚合物的紫外-可见吸收、荧光发射及循环伏安等基本性能进行探讨可知,随着共聚物中FBT含量的增加,共聚物薄膜的吸收起始波长及荧光发射波长均有明显的红移。聚合物薄膜的最大发射峰位于600~650 nm,聚合物中的能量能有效地由PE单元转移到FBT单元上。 相似文献
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Ye GAO Xi Gao JIAN Jin Yan WANG Department of polymer Science College of Chemical Engineering Dalian University of Technology Dalian 《中国化学快报》2000,11(9)
Poly (aryl ether ketone)s (PAEKs) are one of the most important high performanceengineering thermoplastics, widely used in electronic, electric, aircraft and aerospaceindustries. ICI' PEEK has enjoyed much commercial success due to its high operatingtemperatUre and superior strength. It has a Tg of 143oC, a Tin of 334'C and it is quitesolvent resistant. There is a growing demand for new materials to meet increasedperformance requirementS in many areas. Thus there has been considerable r… 相似文献
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以邻氟对苯二酚和4,4′-二氟三苯二甲酮为原料通过亲核缩聚反应,合成含氟聚醚醚酮酮(FPEEKK)材料。 用FTIR、1H NMR和WAXD进行了结构表征,用DSC、TGA测试了热性能,并研究了聚合物的溶解性、吸水性、介电性能及光学性能。 结果表明,含氟聚醚醚酮酮具有较好的热性能(N2气气氛中,5%热分解温度为505 ℃);能溶于氯仿、四氢呋喃和N,N-二甲基甲酰胺等有机溶剂;具有较低的吸水率(0.24%)和介电常数(ε=3.0);在近红外区1300和1550 nm处吸收非常弱。 相似文献
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Mei-Lin Zhang Xiao-Jun Wang Gang Zhang Sheng-Ru Long Jie Yang 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):996-1005
Poly(meta-aryl sulfide sulfone imide imide) (m-PASSII) was synthesized by one-pot process using 4-chlorophthalic anhydride, 3,3′-diamino diphenyl sulfone and sodium sulfide (Na2S· xH2O) as starting materials in N-methyl-2-pyrrolidone at atmospheric pressure. The intrinsic viscosity of m-PASSII was obtained with optimum synthesis conditions is 0.21-0.27 dl/g. The polymer and the separated intermediates which generated during the synthesis process were characterized by elemental analysis, FT-IR spectrum, 1H-NMR spectrum, X-ray diffraction, DSC, TGA and dissolvability experiment. The polymer is found to have excellent thermal performance with glass transition temperature (T g ) of 224°C and initial degradation temperature (T d ) of 441°C. Moreover, the polymer is dissolvable in strong polar solvents. 相似文献
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Kaikai Cao Yujia Zhong Guohu Guan Chuncheng Li Wenxiang Zhu Yaonan Xiao 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(6):508-517
Poly(p-phenylene benzobisoxazole)/poly(pyridobisimidazole) block copolymers (PBO-b-PIPD) were prepared by introducing poly(pyridobisimidazole) (PIPD) moieties into the main chains of poly(p-phenylene benzobisoxazole) (PBO) in order to enhance its photostability. PBO and copolymer fibers were directly prepared from the polymerization solutions by dry-jet wet-spinning. Chemical structures and molecular chains arrangement of the block copolymers were characterized by Fourier transform infrared (FTIR) spectroscopy, solid-state 13C-NMR and wide angle X-ray diffraction (WAXD). Thermal stability of the copolymers was investigated by thermogravimetric analysis (TGA) in nitrogen. Thin films of PBO and copolymers were cast from methanesulfonic acid (MSA) solutions. Both the films and fibers were exposed to UV light to determine their photostability. Changes in the chemical structures and surface morphologies of the films were characterized by FTIR spectra and scanning electronic microscopy (SEM), respectively. After UV light exposure, the retention of strength for copolymer fibers is improved compared to PBO fibers. The results revealed that copolymers suffered less photodegradation in comparison with homopolymer. The mechanism for the improved photostability of the copolymers was discussed. 相似文献
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Poly(aryletherketone)sareoneofthemostimportanthighperformanceengineeringthermoplastics,widelyusedinelectronic,electric,aircraft,andaerospaceindustries.Initially,considerableeffortwasmadetomodifytheirchemicalstructure,essentiallytoimprovetheirthermalproperties'.Inthelastfewyears,moreattentionwaspaidtotheirfunctionalization2.Thiscanbeachievedeitherbychemicalmodificationofthepolymerorbydirectsynthesisusingfunctionalizedmonomers.Inthisletter,wesynthesizedanovelmonomer4byintroducingcyclohexeneringa… 相似文献
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Katarzyna Jaszcz 《Macromolecular Symposia》2007,254(1):109-116
Summary: New functional poly(ester-anhydride)s with allyl pendant groups in the side chains were obtained by polycondensation of sebacic acid (SBA) and poly(3-allyloxy-1,2-propylene succinate) (OSAGE) terminated with carboxyl groups. The carboxyl groups in OSAGE and in SBA were converted to mixed anhydride groups by acetylation with acetic anhydride. After that, prepolymers obtained were condensed in vacuum to yield higher molecular weight poly(ester-anhydride)s. The influence of SBA and OSAGE content in poly(ester-anhydride)s on their selected properties e.g. molecular weight, thermal and solubility characteristics as well as degradation rate and mode, were examined. Poly(ester-anhydride)s were degraded in aqueous buffer of pH 7.4 at 37 °C. The hydrolytic degradation was monitored by determination of weight loss of samples and by determination of ester to anhydride groups ratio. 相似文献
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在水相中,FeCl3催化对甲基苯胺聚合合成了对甲基苯胺三分子聚合物——(N,N′E,N,N′E)-N,N′-(2-氨基-5-甲基-2,5-环己二烯-1,4-二亚基)二(4-甲基苯胺)(1),其结构经X-射线单晶衍射仪表征。1属六方晶系,R3空间群,晶胞参数:a=21.116(2),b=21.116(2),c=10.364(2),α=90°,β=90°,γ=120°,Mr=315.41,Z=9,V=4002.1(10)3,Dc=1.178 g.cm-3,μ=0.070 mm-1,λ=0.710 73,F(000)=1 512,R=0.067 8,wR=0.112 6。 相似文献
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The synthesis of diblock copolymers of poly(N-isopropylacrylamide) (PNIPAM) and poly(vinyl acetate) (PVAc) was performed by macromolecular design via interchange of xanthates (MADIX) process. Following the preparation of methyl (isopropoxycarbonothioyl) sulfanyl acetate (MIPCTSA) as chain transfer agent, it was reacted with vinyl acetate to obtain PVAc macro-chain transfer agent. Then, block copolymerization was completed by successive addition of N-isopropylacrylamide (NIPAM). 1H NMR spectroscopy confirmed the presence of both blocks in the copolymer structure, with the expected composition based on the feed ratio. Size Exclusion Chromatography (SEC) was used to investigate the relative values of molecular characteristics. Only 20% of PVAc was converted to block copolymer. The resultant block copolymer structures were further examined in terms of their morphologies as well as critical micelle concentration (CMC) by using ESEM and Fluorescence Excitation Spectroscopic techniques, respectively. Morphological characterization confirmed amphiphilic block copolymer formation with the existence of mainly ca. 100 nm well distributed micelles. The thermo responsive amphiphilic behavior of the block copolymer solutions were followed by Dynamic Light Scattering (DLS) technique. 相似文献
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The new chromophore molecules with nonlinear optical (NLO) properties were prepared by Knoevenagel condensation from 1,8-dimethoxy-4,5-diformyl-9,10-dihydroanthracene and isophorone derivative in the presence of piperidine and acetic acid. In these chromophore, the ring-locked trienes were employed as the conjugation bridge and electron acceptor in D-π-A units. The key intermediate dialdehyde was conveniently prepared via a three step reaction, in which 1,8-dimethoxyanthraquinone was reduced with zinc/acetic acid and sodium/ethanol successively, followed by formylation with 1,1-dichlorodimethyl ether in the presence of TiCI4. The solvatochromism and UV spectra indicate that they have higher second-order nonlinear hyperpolarizability μβ values than the corresponding reference compound, without red shift of the charge transfer band. 相似文献
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4-Chloro-2,5-bis(4-fluorophenyl)oxazole monomer has successfully been synthesized using cyclization reaction of 4-fluorobenzoyl cyanide with 4-fluorobenzaldehyde. This monomer was converted to poly(aryl ether)s by nucleophilic substitution of the fluorine atoms on the benzene rings of oxazole monomer with bisphenol A. The influence of the reaction time on the molecular weight had been investigated. The polymers were identified by FT-IR,1H-NMR and TGA. The products exhibited weight-average molar masses up to 2.81 x 104g mol−1 in GPC. These poly(aryl ether)s showed very high thermal stability up to 363 °C for 5 % weight loss in TGA under N2. 相似文献