Deformation Mechanisms of Polyolefin Hard-Elastic Films during Uniaxial Stretching

Polyolefin hard-elastic films composed of highly oriented lamellar stacks can serve as one ideal sample to study the intrinsic deformation mechanisms of lamellar stacks, the basic structural and deformation unit in semi-crystalline polymers. With the quick development of synchrotron radiation X-ray scattering techniques, we were able to track the structural evolutions of hard-elastic polyolefin films during uniaxial stretching with the aid of a home-made tensile device. The effects of strain, strain rate and temperature on the nonlinear mechanical behavior and structural evolution of oriented lamellar stacks were systematically studied. And the different dominant deformation mechanisms, including microphase separation within interlamellar amorphous, microbuckling behaviors, crystal slipping and melting-recrystallization, dominate in different external tensile fields. The roadmap of microstructural evolutions of oriented lamellar stacks was constructed in temperature-strain space, which might aid to guiding the real processing of high-performance polymer films.
References:
Macromolecules 2018, 51, (7), 2690-2705.
Polymer 2019, 178, 121579.
Polymer 2018, 148, 79-92
Polymer 2018, 154, 48-54.