High-temperature And High Toughness Resistant Thermosetting Polyimide Resins And Their Composites

Polyimides have been used in many industries such as aerospace, microelectronics. Polyimides are an important class of thermally stable materials because of their excellent properties.When phenylethynyl terminated imide Oligomers were cured, the phenylethynyl groups react to provide a three-dimensional network. The cure involves a complex free radical reaction leading to chain extension, branching and crosslinking without the evolution of volatiles. the cured resins exhibit an excellent combination of properties including high Tg, good toughness, good thermal stabilityand excellent mechanical properties. Therefore developments in the area of phenylethynyl terminated imide oligomer technology have been produced promising results. The following work have been investigated:1. Diamine of 3,5-diamino-4'-phenylethynylbenzophe-none was synthesized from 3,5-dinitrobenzoyl chloride as a starting material.2. PI neat resin were prepared by isomeric dianhydrides (3,3',4,4'-BPDA)and variety mixture of 4,4'-ODA, MDA with the diamine DPEB, endcapped with PEPA.We studied the DPEB their effect on the neat resin.3. The effects of the molecular structure and the molecular weight on thermal stability and mechanical properties were studied.The results showed that the glass transition temperature of polyimides and the tensile strength of the neat resin was improved when the content of the diamine DPEB, and have good thermal stability. We expect to find a class of thermolsetting polyimide of good thermal stability properties by in these areas's study. Nowdays, there have little discuss in this field, thermosetting polyimide containing pendent phenylethynyl groups is not only a new research, but also it is conductive to high toughness and high-temperature resistant thermosetting polyimide resins.