Thermally-inverted strain-optical and stress-optical behavior of poly(4-methyl-1-pentene) in rubbery state

Abstract

The unique temperature-dependent strain-optical and stress-optical behavior of poly(4-methyl-1-pentene) (P4MP) is reported during uniaxial deformation in the rubbery state. For P4MP the birefringence is found to increase with an increase in deformation temperature, which is opposite to the behavior of other polyolefins such as polypropylene and polyethylene. Real-time stress-strain-birefringence measurements are supplemented with offline wide-angle X-ray diffraction (WAXD) and infrared (FTIR) measurements.