Recent Advances in Bismaleimides and Epoxy-Lmide/ Bismaleimide Formulations and Composites

Abstract

Abstract In recent years there has been a rapid development in the area of temperature-resistant thermosets. Polyimides in particular are gaining wide acceptance by the industry because they combine a number of unique features, including excellent physical property retention at elevated temperatures and in wet environments, almost constant electrical properties over a wide range of temperatures, and nonflammability properties. Their commercial success is based on the fact that the raw materials, such as aromatic diamines and tetracarboxylic acid dianhydrides, are relatively cheap and the chemical synthesis is, in most instances, straightforward. Polyimides still carry the image of being difficult to process. Considerable effort continues to be devoted to improving the processability without sacrificing thermal stability. The major application for thermosetting polyimides is as matrices in advanced composites.