Novel modified bismaleimide resins with improved ablativity

✍ Scribed by Guozheng Liang; Jing Fan

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 258 KB
• Volume: 73
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19990829)73:9<1623::aid-app3>3.0.co;2-z

✦ Synopsis

To improve the ablativity of bismaleimide-type resins, a series of novel allyl compounds containing boron in their molecular structure, designated as ACB, were synthesized and characterized. The copolymers made up of 4,4Ј-bismaleimidodiphenyl methane (BDM) and each ACB were prepared. The properties of the prepolymers and cured resins were all studied in detail. Results show that the prepolymers of BDM/ACB systems have similar processing characteristics such as solubility in acetone and reactivity to those of ordinary BMI resins made up of BDM and allyl compounds without boron, such as the famous BDM/BA (O,OЈ-diallylbisphenol A) system, while the thermal resistance and ablativity of the former are better than those of the latter. Thermogravimetric analysis (TGA) in a nitrogen atmosphere revealed that the BDM/ACB systems were stable up to 480°C and their char yields at 800°C under anaerobic conditions were more than 50%. However, the char yield at 700°C of the BDM/BA system is only about 21%.