Fabrication and optical characterization, 1998

In this study the mechanical and optical properties of polyphenylene sulfide (PPS) films of three different thicknesses (1 mil, 3 mil, and 4 mil) were investigated in order to characterize the behaviors of this high performance polymer. The project has two major components; characterization of the stress-strain properties of PPS films at room temperature and fabrication and characterization of oriented PPS films at temperatures above and below the glass transition temperature. The mechanical properties such as Youngs Modulus, True Stress, and True Strain at Break and Maximum Extension were identified by stretching at room temperature using the Instron 4505 Tensile Tester. The relationship between the mechanical properties and deformation rate was determined by varying the extension rate from 0.2%/min. to 300%/min. Oriented samples were fabricated by stretching at four different temperatures; two temperatures below the glass transition temperature (Tg), one temperature near Tg, and one temperature above Tg using an ambient environmental chamber. A Metricon 2010 Optical Wave Guide Coupling Instrument was used to identify structural information such as three-dimensional refractive indices, three-dimensional birefringence, and the molecular symmetry axis. A significant result of this study is that the Youngs modulus measurements show a decrease in magnitude with respect to increasing deformation rate for both parallel and perpendicular samples. Youngs Modulus for both parallel and perpendicular samples falls within error bars throughout the deformation range. The true strain results show that the perpendicular samples stretch and average of 14% more than the parallel samples before failure. The optical results show that PPS film is biaxially oriented and the in-plane indices are most sensitive when stretched at temperatures above the Tg. The average refractive index remains constant with strain, which implies that the structural crystallinity of PPS is not affected by drawing