Development of the polymide resin system, known as B1, involved producing a newly synthesized monomer, 178A2, as a replacement for methylene dianiline used in the PMR15 system. Production scale quantities of B1 have been produced.
B1 composite property data has shown significantly lower weight loss at a high temperature (300 C) than PMR15; similar property retention to PMR15 in interlaminar shear and flexural property tests in a range of 250 C to 300 C for 6000 h; and similar microcracking properties as PMR15. The level of toxicity for the B1 formulation is less than that for PMR15.
B1 is currently being worked on in 2 prototypes: the leading cycle section of an Alpha jet tail plane and in a fighter plane engine duct.
THE THERMOSETTING POLYIMIDE, PMR-15, IS THE LEADING CONTENDER FOR USE IN POLYMER MATRIX COMPOSITES CAPABLE OF APPLICATION AT TEMPERATURES AROUND 250-300 CELSIUS DEGREES. ALTHOUGH THE PROPERTIES OF PMR-15 ARE GENERALLY GOOD, ITS WIDESPREAD USE IN AIRCRAFT AND AERO ENGINES HAS BEEN HAMPERED BY A NUMBER OF DRAWBACKS. AMONG THESE ARE MICROCRACKING DUE TO THERMAL CYCLING, HIGH TEMPERATURE PROCESSING, IRREPRODUCIBILITY AND THE TOXICITY OF THE CONSTITUENT METHYLENE DIANILINE.
THE MAIN AIM OF THE BRITE PROGRAMME IS TO DEVELOP A HIGH TEMPERATURE POLYIMIDE WITH EXCELLENT PROPERTIES FOR CONTINUOUS USE ABOVE 250 CELSIUS DEGREES. FEATURES OF THE NEW SYSTEM SHOULD INCLUDE LOW TOXICITY, EASY PROCESSING, TOUGHNESS AND RESISTANCE TO MICROCRACKING DUE TO THERMAL CYCLING.
Funding SchemeCSC - Cost-sharing contracts
EC2M 7BA London
KT22 7SA Leatherhead, Surrey