THE CHARACTERIZATION OF POLYMER DEFORMATION BY RHEOOPTICAL FOURIER-TRANSFORM INFRARED-SPECTROSCOPY

The mechanical properties of polymeric materials are of considerable importance to their engineering applications. Apart from the chemical structure and the thermal history, molecular orientation has a major influence on the mechanical properties of a polymer. The increased need for more detailed data and a better understanding of the mechanisms involved in polymer deformation has led to the search for new experimental techniques to characterize transient structural changes during mechanical processes. With the advent of rapid-scanning Fourier - transform infrared (FTIR) spectroscopy, simultaneous vibrational spectroscopic and mechanical (so-called rheo-optical) measurements during the deformation of polymers have emerged as a very informative probe for the study of deformation and relaxation phenomena in polymer films in the late seventies and have since then been applied to obtain data on strain-induced crystallization and orientational and conformational changes during mechanical treatment of a wide variety of polymers.