Investigation into the Injection Molding of PMR-15 Polymide.

摘要

The excellent high temperature mechanical properties of polyimide resins have lead to their increasing use in high performance applications. Present employment of this material includes fiber-reinforced composite structures, bearings, seals, valve seats, bushings, piston rings, electrical connectors, switch components, abrasive wheel binders, aircraft interior panels, circuit boards, and jet engine parts including engine cowlings and high speed fan blades 1-6. Both thermoplastic and thermosetting polyimides are commercially available. The thermosetting materials were developed first and are much more widely used than the newer thermoplastic resins. Early thermosetting polyimide systems were based on condensation reactions. They were difficult to process, requiring the use of high boiling point solvents. Solvent residues and reaction by-products lead to void formation and premature failure of fabricated parts.