作者:M. Berrada、F. Carriere、Y. Abboud、A. Abourriche、A. Benamara、N. Lajrhed、M. Kabbaj、M. Berrada
DOI:10.1039/b205150h
日期:——
The present necessity to use heat-resistant materials in electronics justifies the scientific interest in different heterocyclic polymers. This paper is especially concerned with the preparation of novel heat-resistant polyimides having bisbenzimidazole moieties in the main chain and their applications as dielectric films. A soluble copolyimide was prepared by a two-step synthesis from aromatic dianhydrides and aromatic diamines. The bisbenzimidazole diamine was prepared by reduction of the corresponding dinitro compound. The diamine was reacted with various aromatic dianhydrides to prepare a series of alternating benzimidazoleâimide copolymers via the poly(amic acid) precursors and thermal or chemical imidization. Monomers and polymers were characterized by conventional methods and their physical properties such as solution viscosity, solubility properties, thermal stability and thermal behaviour were studied. All copolymers were obtained in high yields having inherent viscosities ηinh that ranged from 0.60 to 0.98 dL gâ1. Thin films of the copolymer were tough and flexible, having tensile strengths as high as 100 MPa. Glass transition temperatures were observed between 275 and 328 °C. Thermogravimetric analyses indicated that the thermal degradation of poly(benzimidazoleâimide) occurs around 530 °C, which is ca. 80 °C higher than polyimide, confirming that the introduction of the bisbenzimidazole component improved the thermal stability of polyimide.
目前电子领域对耐热材料的需求使得不同的杂环聚合物引起了科学界的关注。本文特别关注含有双苯并咪唑基团的新型耐热聚酰亚胺的制备及其作为绝缘薄膜的应用。通过对芳香二酐和芳香二胺的两步合成,制备了一种可溶性共聚酰亚胺。双苯并咪唑二胺是通过还原相应的二硝基化合物制备的。该二胺与多种芳香二酐反应,通过聚(酰胺酸)前驱体及热或化学酰亚胺化反应制备出一系列交替的苯并咪唑-酰亚胺共聚物。单体和聚合物通过常规方法进行了表征,并研究了其物理性质,如溶液粘度、溶解特性、热稳定性和热行为。所有共聚物都以高产率获得,固有粘度ηinh范围为0.60至0.98 dL g⁻¹。共聚物的薄膜坚韧且柔韧,拉伸强度高达100 MPa。玻璃转变温度在275至328°C之间。热重分析表明,聚(苯并咪唑-酰亚胺)的热降解发生在约530°C,这比聚酰亚胺高出约80°C,确认了双苯并咪唑组分的引入提高了聚酰亚胺的热稳定性。