POST CURING EFFECTS ON OUT-OF-AUTOCLAVE BMI COMPOSITE PANELS

摘要

Bismaleimides (BMI) are thermosetting polymers used in the aerospace industry because theyrnexhibit good physical properties at elevated temperatures and wet environments. BMI basedrncomposites are used as a replacement for conventional epoxy resins at higher servicerntemperatures. Out-of-Autoclave processing of BMI composites is similar to epoxies but requirernhigher cure temperatures. Post curing can be used to improve degree of cure which translates tornimprovement in glass transition temperature and resin dominated properties such as interlaminarrnshear strength. In the current research, carbon fiber/ BMI composite laminates are manufacturedrnby out-of-autoclave processing. The effect of post cure cycles on glass transition temperature isrninvestigated using a dynamic mechanical analyzer. The interlaminar shear strength of post curedrnsamples is measured at room temperature as well as elevated temperatures. It was found that postrncuring at temperatures upto 246 ℃ results in an improvement in interlaminar shear strength andrnglass transition temperature. Laminates fabricated via out-of-autoclave processing exhibitedrnproperties comparable to that of autoclave cured composites.