Rheo-Optical FT-IR Spectroscopy of Polyurethane-polyolefine Blends During Cyclic Elongation and Recovery

Abstract

FT-IR spectra have been recorded during cyclic uniaxial elongation and recovery of films of thermoplastic polyester- and polyether-polyurethane elastomers (TPU) and their blends with polyolefines (polyethylene and polypropylene). From these spectra the orientation functions of the individual segments have been calculated. The TPU hard segments are built up to 4,4'-diphenyl methane di-isocyanate (MDI) units with 1,4-butandiol as chain extender. The soft segments used in this study consists of polyethers or polyesters. We find reduced stress and strain levels for the blends as well as weaker orientation of the segments. For polyether-polyurethane blends with polypropylene we notice extended strain.