PEEK-PEDEK嵌段共聚物非等温结晶动力学研究

PEEK以其优异的热稳定性和耐溶剂性被广泛应用在航空航天和电子电气等领域^[1].经过增强后的PEEK长期使用温度(UL温度指数)可达523 K.但在温度高于523 K的情况下,模量下降较快,这在一定程度上限制了其应用.在PEEK的分子链上引入刚性较强地联苯基团,可以有效的提高分子链的刚性,使聚合物的玻璃化转变温度得以提高^[2,3].我们曾合成了一系列含有刚性单体联苯二酚的嵌段共聚物,并对其热性能进行了研究^[4],本文着重对这一系列共聚物的非等温结晶动力学进行研究.     

联苯并环丁烯的制备及其聚合物的热稳定性

苯并环丁烯树脂具有优异的综合性能,可作为微电子器件中的高性能介电薄膜材料。其优异的性能满足大规模集成电路(MCM)、微电机系统(MEMS)、液晶显示器等器件的苛刻性能要求,在微电子领域有着极为重要的应用且前景广阔[1,2,3]。苯并环丁烯单体的种类较多,其聚合物大多具有优异的     

聚醚醚酮酮强电场下的熔融结晶

聚醚醚酮酮 (PEEKK)是在聚醚醚酮 (PEEK)基础上开发成功的一种新型特种工程塑料 ,由于酮基与醚基比例的提高 ,其耐热等级比 PEEK提高了近 2 0℃ . Zimmermann等 [1] 首先报道了 PEEKK的晶体结构 ,同 PEEK类似 ,也为正交晶系 ,Pbcn空间群 .众所周知 ,结晶聚合物材料的产品性能与其结晶条件密切相关 .我们先后对 PEEKK的等温及非等温熔融与冷结晶动力学 [2 ,3] ,晶胞参数及结晶度随结晶温度变化关系 [4 ] ,拉伸诱变多晶型5,6] ,溶剂诱变多晶型进行了研究 [7] .但电场效应对聚合物结晶的影响尚罕见报道 [8] .本文对 PEEKK强电场…     

高度可溶聚苝酰亚胺材料的合成及性能研究

聚酰亚胺是一类具有优异综合性能的聚合物材料 [1,2 ] .近年来 ,合成含荧光染料的可溶性聚酰亚胺材料在聚合物化学领域引起了广泛兴趣 [3～ 11] ,人们期望这类聚合物材料会比其小分子材料具有更加优越的性能 .小分子酰亚胺荧光染料具有极高的荧光量子效率、光化学和热稳定性 ,可广泛应用于光学开关[12 ] 、电致发光器件 [13,14 ] 和太阳能转换器 [15] 等领域 ,但是由于的大π键平面共轭结构 ,使得材料的溶解性能极差 ,难以加工 .最近 ,本实验室通过合成含叔丁基的芳香二胺 [4,4′-亚甲基双 ( 2 -叔丁基苯胺 ) ]与各种芳香四酸二酐反应…     

一种新型间位聚芳醚酮的晶体结构

聚醚醚酮 (PEEK)自英国 ICI公司开发并工业化以来 ,由于其优异的性能已在机械、航天等领域得到广泛应用 .但 PEEK的 Tg 只有 41 6K,影响了使用范围 .因此其它聚芳醚酮类聚合物相继被开发出来 .但这些聚芳醚酮的主链结构大都为全对位连接 ,使其熔点较高以至加工难度增大 .如果在聚合物主链结构中引入间位结构 ,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[1,2 ] .新型间位聚醚酮醚酮酮 (PEKEKm K)是其中一种 ,其玻璃化转变温度 Tg 为 41 7K,Tm 为 5 82 K.无论熔体结晶、冷结晶和溶剂诱变结晶 ,PEKEKm K都只出…     

发蓝光材料聚烷基芴的合成和性能研究

聚芴及其衍生物是一类极具光、电活性的重要有机聚合物材料 .早在 90年代初 ,Fukuda等[1,2 ]首先报道了聚芴的合成 .在过去的几年中 ,由于这类聚合物及其衍生物卓越的光电性能 ,使其在发光二极管、激光器件、导电光刻蚀、光电池、生物传感器件等方面得到了广泛应用 ,从而推动了这一领域的飞速发展 .国外研究者在这方面进行了大量的研究工作 ,合成了一系列具有光电性能的聚芴共聚物 ,并用于研制各种光电器件[3～ 10 ] .从单体合成方法来看 ,大多都有采用文献 [1 ]所述的方法 ,但该方法要求在无水 (正丁基锂 )、无氧 (Ar气 )、低温 ( - 78℃ …     

基于Diels-Alder反应的可交联空穴传输材料的合成及其在聚合物发光二极管中的应用

设计合成了一种侧链含呋喃的可交联共轭聚合物空穴传输材料聚{2,7-[9,9-二(6-(2-呋喃甲氧基)己基)芴]-共-4,4′-(4″-丁基)三苯胺}(P1)和侧链含马来酰亚胺的共轭小分子交联剂N,N′-二[4-(6-马来酰亚氨基己基)苯基]-N,N′-二苯基联苯二胺(M1).基于呋喃和马来酰亚胺间Diels-Alder反应,P1和M1共混膜可在150°C下热处理快速交联形成具有优异抗溶剂性的薄膜,同时薄膜的光电性能可以通过控制P1和M1的共混比例进行有效调节.器件研究结果表明,基于P1+M1交联的薄膜表现出了优异的空穴传输、电子阻挡性质,应用于聚合物发光二极管时可有效避免由传统空穴传输材料聚3,4-亚乙二氧基噻吩/聚苯乙烯磺酸(PEDOT:PSS)作为单一界面层引起的发光淬灭现象,使相应器件性能得到大幅提升.当M1添加量为10%时,相关器件表现出了最佳的器件性能,器件的最大电流效率为9.0 cd A~(-1),最大亮度为35681 cd m~(-2),启亮电压为3.2 V.     

基于膜厚与分子量优化策略实现高效近红外有机光探测器

利用基于[1,2,3]三唑并[4,5-f]异吲哚-5,7(2H,6H)-二酮(TzBI)共轭聚合物PTzBI-Cl为给体,非富勒烯小分子Y6DT为受体,制备基于倒装结构的有机本体异质结光探测器.基于高分子量聚合物PTzBI-Cl-H制备的器件比低分子量材料制备的器件具有更低的暗电流和更高的光探测性能.通过对PTzBI-...     

含氟聚合物共混对聚醚醚酮结晶行为的影响

通过示差扫描量热仪(DSC)对含氟聚合物与聚醚醚酮(PEEK)共混物的非等温结晶熔融行为和等温结晶熔融行为进行了研究.研究表明:不同的含氟聚合物以及具有不同端基的同种含氟聚合物对PEEK的结晶行为有不同的影响.端基为酰氟(COF)的乙烯-四氟乙烯共聚物(ETFE)能促进PEEK结晶时的成核,加快PEEK的等温结晶速率,而聚四氟乙烯(PTFE)则会减慢PEEK的等温结晶速率.     

低介电常数含氟聚芳醚的合成

计算机的高速发展 ,对于微电子器件 (例如印刷电路板的基材、多级金属互联结构的绝缘电介质层以及电子封装涂料等 )的耐高温材料的需求越来越迫切 ,因此对具有低介电常数、良好的热稳定性、低吸水率、溶解性好的芳香族聚合物的研究已引起极大关注 .其中低介电常数是至关重要的性能之一 .将含氟基团和大体积侧基等引入聚合物链中 ,是降低介电常数的有效方法 [1,2 ] .含氟芳香聚合物不仅在低介电常数微电子绝缘材料方面有重要的应用前景 ,而且在光波导器件和气体选择性透过膜等方面极具应用潜力 [3 ,4 ] .本文合成了一种高含氟量的新型聚芳醚 …     

Highly phenylated poly(aryl ether phthalazine)s

Two series of novel amorphous poly(aryl ether phthalazine)s have been prepared via an intramolecular ring closure reaction of poly(aryl ether ketone)s (PAEKs) with hydrazine monohydrate. Fluorinated PAEKs, which display solubility in solvents incorporating a ketone functionality such as acetone or ethyl acetate, were converted to poly(aryl ether phthalazine)s to observe if these polymers would display similar solubility characteristics. The poly(aryl ether phthalazine)s have glass transition temperatures in the range of 278–320°C and show 5% weight loss points greater than 500°C in air and nitrogen atmospheres. The fluorinated poly(aryl ether phthalazine)s were not soluble in ketonic solvents. A series of poly(aryl ether phthalazine)s incorporating pendant 2-naphthalenyl moieties has been prepared in an attempt to produce amorphous, thermally stable polymers with high glass transition temperatures. The polymers have glass transition temperatures in the range of 287–334°C and show 5% weight loss points greater than 500°C in air and nitrogen atmospheres. Poly(aryl ether phthalazine)s undergo an exothermic reaction above the glass transition temperature. The major product of this reaction is a rearrangement of the phthalazine moieties to quiazoline moieties, however some crosslinking of the polymers occurs. Cured samples of the poly(aryl ether phthalazine)s show a small increase in the polymer T_g and are insoluble in all solvents tested. © 1996 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 34:1897–1905, 1996     

含硫醚可溶性聚芳醚酮的合成及电子束辐照的研究

聚醚醚酮(PEEK)因具有优异的机械性能、耐热性、耐化学腐蚀性等优点而广泛应用于航空航天、电子器件、机械仪表等领域．具有刚性结构的聚醚醚酮有极好的耐溶剂性,不溶于一般的有机溶剂,并且需在较高的温度下进行加工．近20年来,人们不断开发性能优异的聚醚醚酮新材料,在聚合物主链上引入不同的功能基团(如萘环、氮杂萘环等)及侧基功能基团(如苯、三氟甲基等),以提高聚芳醚酮的溶解性,或者通过共聚和共混等方式进一步改善材料的使用性能和加工性能,     

Self-Crosslinkable poly(arylene ether)s containing pendent phenylenetriazene groups

Self-crosslinkable poly(arylene ether)s 6 , and 8 , containing pendent triazene groups were prepared by nucleophilic substitution reaction of poly(arylene ether)s 5 , and 7 , respectively, with 1-[4-(4-hydroxyphenoxy)phenylene]triazenes, 4 , in the presence of potassium carbonate in N,N-dimethylacetamide. A series of triazenes 4 containing various substituents have been synthesized. Self-crosslinkable polymer 6e containing phenyl-substituted triazene pendants can be crosslinked at 215°C, which is about 40°C lower than the glass transition temperature of the virgin base polymer 5 . The degree of crosslinking can be tailored by varying the concentration of the pendent phenylenetriazene groups in the polymer. After curing, the flexible polymer films (ca. 10 μm thick) exhibit high gel contents, increased glass transition temperatures, improved resistance to organic solvents, and little change in dielectric constant and thermal stability. These self-crosslinkable poly(arylene ether)s are potential candidates for electronic applications. © 1994 John Wiley & Sons, Inc.     

Novel fluorinated poly(aryl ether ketone)s

Two novel fluorinated monomers were prepared and polymerized with biphenols to produce amorphous, thermally stable poly(aryl ether ketone)s. The properties of the fluorinated polymers are compared to those of unfluorinated, amorphous poly(aryl ether ketone)s. The presence of fluorine in the polymers was found to cause a decrease in glass transition temperature and Young's moduli, however, no increase in thermal stability was observed. The fluorinated polymers are soluble in common organic solvents such as chloroform and methylene chloride at room temperature, and also show solubility in solvents containing a ketonic moiety, such as acetone. Evidence of polymer branching through fluorines considered to be unreactive under the polymerization conditions was found. Efforts were made to evaluate the reactivity of fluorine atoms under the polymerization conditions using both molecular modeling and ¹⁹F-NMR to ascertain if such branching could be avoided. © 1995 John Wiley & Sons, Inc.     

新型可溶性含氟聚芳醚酮的合成、表征及性能

制备了新型可溶性含氟聚芳醚酮高性能材料, 使该材料结合了含氟聚合物与聚芳醚酮两种材料的优点, 既具有很好的热稳定性、溶解性和阻燃性, 又有较低的介电常数和吸湿性[5,9,10]. 对于提高聚芳醚酮类材料的性能, 拓展其使用范围和加工方法具有很大的开发前景和实用价值.     

Synthesis of photoreactive isopropyl-substituted poly(phenylene ether ether ketone)

Isopropyl substituted poly(phenylene ether ether ketone) with a high molecular weight was prepared by nucleophilic substitution reaction of isopropyl-substituted difluoro diaryl ether with hydroquinone. This polymer was amorphous and soluble in common organic solvents, such as THF, chloroform, and cyclohexanone. Thermogravimetry of the polymer showed good thermal stability, indicating that a 10% weight loss of the polymer was observed at 470°C in nitrogen. The glass transition temperature of the polymer was 145°C. The polymer had a broad UV absorption band over 250–380 nm. The polymer acted as a photosensitive resist of negative type for UV radiation. The resist had a sensitivity of 40 mJ/cm² and a contrast of 2.8, when it was developed with DMF at room temperature. © 1997 John Wiley & Sons, Inc.     

The effect of ions irradiation on the thermal properties of poly(ether ether ketone)

The effect of irradiating amorphous poly (ether ether ketone), PEEK, with ions, 11 MeV proton (H⁺), and 25.6 MeV helium (He²⁺), has been investigated focusing on the changes in thermal properties. The extent of chain scission and crosslinking was evaluated using the Charlesby‐Pinner equation. Crosslinking increased the glass transition temperature (T_g) in line with the DiBenedetto equation from which the crosslinking constant for each ion was calculated. The effect of irradiation on the thermal degradation kinetics was studied in an argon atmosphere at a constant heating rate by mean of the Chang and the second Kissinger methods. Irradiation significantly reduced the thermal stability of the polymer and its service lifetime. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2212–2221, 2008     

Synthesis and cationic photopolymerization of new fluorinated,polyfunctional propenyl ether oligomers

New fluorinated, polyfunctional propenyl ether functionalized resins were synthesized, and their behavior in cationic photopolymerization was investigated. The photopolymerization proceeded efficiently with a high double‐bond conversion (>90%), giving rise to UV‐cured coatings characterized by low glass‐transition temperatures (?33 °C ≤ glass‐transition temperature ≤ ?15 °C) and hydrophobic surface properties. A fluorinated additive was also employed as a reactive additive in the cationic photopolymerization of trimethylolpropane tripropenyl ether, increasing the double‐bond conversion, polymer network flexibility, thermal stability, and surface hydrophobicity. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6943–6951, 2006     

Radiochemical ageing of poly(ether ether ketone)

Thin (60 μm) and thick (250 μm) samples of poly(ether ether ketone) were subjected to radiochemical ageing at 24 kGy h⁻¹ dose rate for doses up to 30.7 MGy at 60 °C in air. FTIR spectrophotometry (hydroxyl and carbonyl build-up), ATR microscopy (oxidation profiles), ammonia gaseous treatment (determination of carbonyl nature), density, DSC (glass transition temperature, cold crystallization and melting point changes), and gel content measurements (crosslinking) were conducted for examination of polymer degradation. Thin samples were shown to undergo principally chain scission process whereas thick ones undergo mainly crosslinking. This difference can be attributed to the kinetic control of oxidation by oxygen diffusion. A mechanistic scheme was proposed from radiochemical yields estimations.     

Thermal chemistry of poly(aryl ether phthalazine)s and the synthesis of poly(aryl ether quinazoline)s

Poly(aryl ether phthalazine)s were found to undergo an exothermic reaction at a temperature range of 360–440°C. We elucidated the origin of the exothermic reaction and the physiochemical phenomena associated with it, based on thermal analyses, model compound studies, and ¹³C solid-state NMR studies. At elevated temperatures, polymers containing a diphenylphthalazine moiety 4 underwent extensive thermal crosslinking reactions as a result of a nitrogen elimination reaction of the phthalazine moiety. However, polymers containing the tetraphenyl or hexaphenyl phthalazine moiety 5 and 6 were found to undergo principally a backbone rearrangement reaction, in which the phthalazine moiety rearranged to a quinazoline. Utilizing this efficient thermal rearrangement of polyphenylated phthalazines, we have prepared a novel activated difluoride, 2,4-bis(4-fluorophenyl)-,5,6,7,8-tetraphenylquinazoline 9d, which underwent high-temperature solution polycondensation with BPA to give the quinazoline containing poly(aryl ether) 14. Polymer 14 is amorphous, has a glass transition temperature of 264°C, and has high thermooxidative stability with 5% weight loss being recorded at 514°C in nitrogen. © 1996 John Wiley & Sons, Inc.