Mechanical Property Determination for Supported Polymer Films using Double Bending Beams

ABSTRACTA double-bending-beam technique has been developed to determine the mechanical properties (e.g., the elastic stiffness parameter and the in-plane coefficient of thermal expansion) of thin polymer films during thermal cycling. The mechanical properties of poly(methyl methacrylate) and a polyimide have been determined from the combined stress-temperature relationships of identical polymer films coated on two rigid beams (each with a distinctly different Young's modulus and coefficient of thermal expansion). The measured mechanical properties were found to agree with data obtained using conventional techniques. The double-bending-beam technique can be applied to a wide variety of dry and wet processing situations involving thin polymer films.