Polymer Engineering and Science · 1978 · 22 citations · 0 references
Natural SciencesMaterials EngineeringMaterials SciencePolymer EngineeringPolymer MaterialsThin FilmsPolymer CharacterizationPolymer PhysicsPolymer StabilityPolymer Thin FilmsStress RelaxationThin Film Mechanical PropertiesAnisotropyDimensional StabilityMechanical Properties Of FilmsPolyimidesPolymer Relaxation ProcessesStability Of Thin FilmsStress Relaxation Of PolymersThermal Expansion In Polymers
Abstract In‐plane mechanical properties, coefficients of thermal and hygroscopic expansion, and dimensional changes due to stress relaxation were measured as a function of direction in one, three, and five‐mil polyimide films. Although these films were made by a casting process, they exhibited significant anisotropy in the properties tested. This anisotropy was apparently due to preferential orientation of the polymer which occurred during the manufacturing process.