Thermal Expansion of the Crystal Lattice of Novel Thermoplastic Polyimides

摘要

The coefficient of thermal expansion of the crystal lattice of severalthermoplastic polyimides has been measured using wide angle X-ray scattering. A novel approach was used to measure the c-axis expansion, in which highly oriented samples were created by treatment in n-methyl pyrrolidinone. Exposure to NMP at the reflux temperature resulted in films oriented with their c-axis aligned along the film normal. The c-axis showed no shift with temperature indicating a very low thermal expansion coefficient.