Low-Temperature Rheo-Optical Fourier Transform near Infrared Spectroscopy of Poly(Dimethylsiloxane)/Polycarbonate Copolymers

Abstract

This communication outlines the potential of variable-temperature Fourier transform near infrared (FT-NIR) spectroscopy to study in situ the anisotropy induced in polymers by mechanical deformation. For this purpose, a series of poly(dimethylsiloxane) (PDMS)/ polycarbonate (PC) copolymers with varying compositions and block lengths were investigated by simultaneous mechanical and Fourier transform near infrared (FT-NIR) spectroscopic, so-called rheo-optical, measurements during cyclic elongation-recovery procedures between +22°C and-55°C. Depending on the composition and block lengths of the block copolymers, different orientation and recovery phenomena were observed for the hard (PC) and soft (PDMS) segments and, for the fi rst time, straininduced crystallisation of the PDMS-segments was derived from on-line FT-NIR spectroscopic measurements at-55°C.