聚苯基单醚喹噁啉薄膜的性能与物理老化

研究了物理老化对聚苯基单醚喹啉薄膜的结构与力学性能的影响 .用差示扫描量热计 (DSC)及正电子湮没寿命谱 (PALS)方法表征了两种不同物理老化条件试样的凝聚结构以及自由体积的差别 .结果表明 ,物理老化使聚苯基单醚喹啉薄膜玻璃化转变温度移向高温 ,在其末端出现热焓吸收峰 ,分子链堆砌紧密使自由体积减小 ,分子可动性降低 .用动态力学分析 (DMTA)以及静态拉伸性能测试等方法研究了两类试样的力学性能 ,结果表明 ,物理老化后 ,试样的动态储能模量稍有增加 ,力学损耗降低 .而静态拉伸实验的断裂应变降低 ,屈服应力增加 ,断裂能降低 ,试样在宏观上由韧性断裂变为明显的脆性断裂 .     

物理老化对聚苯基单醚喹啉薄膜银纹化的影响

物理老化实质上是聚合物材料在 Tg 以下存放过程中 ,其凝聚态结构通过链段或更小运动单元的运动 ,从热力学非平衡态向平衡态过渡的一个结构弛豫过程[1] .在这一过程中 ,聚合物的密度、自由体积、焓、熵和力学性质随温度和时间产生变化 .因为银纹化是聚合物的特性 ,所以银纹化也将随结构回复过程而产生变化 .有关物理老化对聚合物银纹化的影响尚未得出一致的结论 [2～ 4 ] .聚苯基单醚喹啉 (结构见 Scheme1 )是一种高性能的芳杂环聚合物 [5] ,它可以在比较苛刻的条件下作为绝缘材料和膜材料使用 .有关这类高性能的芳杂环聚合物的物理老化…     

聚苯基喹噁啉的研究与应用进展

聚苯基喹噁啉(PPQ)是一类重要的热塑性芳杂环聚合物材料。苯基取代喹噁啉环赋予了PPQ优良的耐热稳定性、耐水解性以及在有机溶剂中良好的溶解性。本文综述了近年来国内外在PPQ材料基础研究与应用领域内的最新进展情况,从四酮单体的合成、PPQ的合成以及在高技术领域中的应用等角度进行了阐述。着重介绍了PPQ在集成电路层间介质材料、先进显示用电子传输材料以及燃料电池质子交换膜材料中的应用,最后结合作者的研究工作对PPQ材料在未来高技术领域中的应用前景进行了展望。     

Fluorene-bridged polyphenylquinoxalines with high solubility and good thermal stability: Synthesis and properties

<正>A novel fluorene-bridged tetraketone monomer,9,9-bis[(4-benzilyloxy)phenyl]fluorene(FLTK) was synthesized and characterized.The tetraketone was polymerized with various aromatic tetraamines to afford a series of polyphenylquinoxalines(PPQs).The obtained polymers were found to be soluble in common organic solvents such as N-methyl-2-pyrrolidone(NMP),chloroform and m-cresol.Flexible and tough PPQ films obtained by spin-casting their NMP solutions exhibited tensile strengths higher than 60 MPa.The films also demonstrated good thermal stability up to 500℃in nitrogen and glass transition temperatures higher than 280℃.In addition,the PPQ films exhibited good hydrolytic stability. High surface and volume resistivity retentions were achieved for the films after immersion or boiling in water for 24 h.     

芳杂环高分子分离膜分离、透过性能的研究——聚苯基单醚喹噁啉(PPQ)超滤膜的研制

随着超滤技术应用范围的不断开拓和新技术工业领域的相继出现,极待开发机械强度好并具有优良的耐温性、耐生物侵蚀性、耐酸碱和耐有机溶剂性等高性能的超滤膜材料,以满足在苛刻条件下的分离、提纯、浓缩与富集以及高温灭菌过程的需要。多年来,国内外学者陆续将多种合成高分子材料用于超滤分离技术中,特别是杂环高分子如聚酰亚胺等,其优良的机械性能、耐温性和耐生物侵蚀性颇引人注目。但是,在已开发的合成高分子超滤膜材料中,由于某些分子的主链上含有—CN、—CONH—、—COOR、—CH_2O—、     

POLYCAPROLACTAM MODIFIED BY POLYPHENYLQUINOXALINE

Three polycaprolactam samples modified by 0.05—0.50% polyphenylquinoxaline(PPQ)by weight were prepared.Their structure and mechanical properties were characterized by FT-IR, SEM, density, tensile, impact, DTAand visco-elastic method, PPQ induced the formation of "crystal grains" distributed evenly over nylon spherulites in modified samples, which were observed for the first time, and strengthened modified samples. Modified nylons had higher crystallinities, higher T_g, more nearly perfect spherulites than MC nylon itself, and showed typical reinforcing effect on mechanical properties.     

INCORPORATION OF METAL IONS INTO POLYPHENYLQUINOXALINE

FeCl_3·6H_2O, NiCl_2, CuCl_2, ZnCl_2 and CrCl_3 have been incorporated into polyphenylquinoxaline by a new method. High-quality, flexible, glass-cast films have been obtained which exhibit increased glass transition temperature and excellent thermal stability. Moduli and tensile strengths of the metal-containing polyphenylquinoxaline films increase surprisingly at elevated temperature. Electrical resistivities of these films fall in the same order range as polyphenylquinoxaline alone. X-ray photoelectron spectroscopic study of metal-containing polyphcnylquinoxaiine films shows that all metals in these films are present in the ionic state, there is charge transfer between nitrogen of polyphenylquinoxaline and Cu~(2+), Zn~(2+) of CuCl_2, ZnCl_2 containing polyphenylquinoxaline films.     

EFFECT OF WATER ON THE CONDUCTIVITY OF PPQ (ClO_4~-) COMPLEX

The preparation of conducting PPQ film was first reported in the previous paper. It is very interesting that this film is highly sensitive to moisture in air. The hydration and dehydration of the film are accompanied by change not only in color but also in conductivity and UV-visible spectrum. The conducting PPQ is reduced to PPQ and loses its conductivity after being soaked in water.     

含苯并呋喃环的聚苯基单醚喹噁啉

由含苯并呋喃环的芳族四酮与芳族四胺进行溶液缩聚反应，合成了两种新的含苯并呋喃环的聚苯基单醚喹啉，用红外光谱、元素分析、差热及热重分析对聚合物进行了表征，测试了力学性能，并对其在较低温度下形成的多孔薄膜进行了分离、透过性能的研究，实验结果表明，聚合物不仅具有优良的耐热性与力学性能，也具有良好的纯水透过率和截留性能．